Magazine reviews and comments.

We have many very favourable customer comments, particularly from Norway, about MonoPulse, some of which are on this site.

However, due to our workload, it is over 2 years since we offered a Model A or Model S floorstander for review. For reviews prior to that, click Model A to follow the string of Model A reviews, and click Model S for the string of Model S reviews, or click on any in the list below to go to that review.

We have never submitted our most recent model, the Model S standmount , for review.

Some highlights

The Model A speaker at its second 'Best Buy' award from the prestigious Hi-Fi Choice.

Hi-Fi Choice"remarkably impressive coherence, especially through the voice band, which seems to be MonoPulse's stock in trade, more accurately and convincingly defining the position of a performer in space."

The MonoPulse Model S loudspeaker was given the top five star rating by What Hi-Fi.

What Hi-Fi"Extraordinary powers of timing and resolution ... the Ss are almost ridiculously good. Music is delivered with a precision that makes other loudspeakers sound blurred and hazy by comparison. The S's vibrancy, accuracy and and rhythmic presence is extraordinary enough to warrant five stars on its own." Five stars

Hi-Fi +The MonoPulse Model A received a fantastic review in Issue 42 of Hi-Fi +.

“sheer vividness of their music making … the shock of reality … a fine partner for low powered valve amps … remarkable immediacy of performance ... the sheer speed and integrity."

"Plenty of deep bass extension. A genuine audiophile product at a very realistic price.”

Keith Howard, consultant Technical Editor for the prestigious Hi-Fi News, about the Model S.

Hi-Fi news"Its fundamental honesty of sound is its key attribute and opens a window on a musical performance in a way that slugged-sounding speakers - of which there are still too many - never can. This is what real high fidelity is all about."

The full review list - click on each to read

HI-FI+, Issue 102, August 2013, Model S - Fine overall coherence, precise imaging, and 25Hz bass »
HI-FI WORLD, May 2013, - Model A - a wide stereo image and an almost holographic feel from the right recordings »
Mono & Stereo High End Audio, Oct 2010, Model S - England holds quite few unique audio jewels »
HI-FI CHOICE, July 2010, Model S - breaks the rules on stereotypes »
HI-FI WORLD, May 2010, ONE SHOUT - MonoPulse's Model S has had a major upgrade. »
HI-FI NEWS, April 2010, Model S - Restored Pulse - major upgrade to MonoPulse S. »
WHAT HI-FI?, AWARDS 2009, Model A awarded FIVE STARS - fabulously, uniquely brilliant. »
WHAT HI-FI?, July 2009, Model A in group test - MonoPulse Model A speakers grip and control information like the Stasi »
WHAT HI-FI?, Ultimate Guide March 2009, Model S - awarding FIVE STARS »
WHAT HI-FI?, December 2008, Model A awarded FIVE STARS - Pulsating floorstanders really do rock our world »
HI-FI CHOICE, December 2008, Model S - MonoPulse has revised the S »
HI-FI WORLD, October 2008, Pulse Rate. Adam Smith listens to MonoPulse's striking new Model A loudspeakers... »
HI-FI CHOICE, August 2008, Model A - offered as prize »
HI-FI NEWS, July 2008, Model A - stylish MonoPulse improved »
HI-FI WORLD, July 2008, Model A, striking design that has just been improved »
HI-FI CHOICE, March 2008, Model S - exeptionally elegant floorstander »
HI-FI CHOICE, Jan 2008, Model A - awarding BEST BUY »
WHAT HI-FI?, Ultimate Guide 2007, Model S - awarding FIVE STARS »
HI-FI NEWS, Aug 2007, Model S direct to the core of the music »
HI-FI CHOICE, Aug 2007, Model S impressively vivid »
WHAT HI-FI?, May 2007, Model S, giving top FIVE STAR award »
HI-FI CHOICE, July 2006, Model A - awarding BEST BUY »
HI-FI NEWS, February 2006, MonoPulse well behaved »
HI-FI+, Issue 42, December 2005, Model A superb transient integrity »
WHAT HI-FI?, December 2005, Model S awarded FIVE STARS »
HI-FI CHOICE, September 2005, Model A something very special »
HI-FI NEWS, July 2005, MonoPulse drivers connected in phase »
THE ENGINEER, July 2005, MonoPulse based on radar technology »
HI-FI NEWS, May 2005, Model S what real high fidelity all about »
HI-FI CHOICE, April 2005, MonoPulse beefs up rolled-steel surround »
HI-FI NEWS, Mar 2005, Model S inherent transparency »
HI-FI NEWS, July 2004, Model A fancy electrostatic sound »
HI-FI CHOICE, May 2004, Model A newly introduced »
HI-FI CHOICE, September 2003, Model S timing positively electrifying »
HI-FI WORLD, August 2003, Model A answer to life, the universe and everything »
HI-FI NEWS, July 2003, MonoPulse launches range of speakers »
HI-FI CHOICE, June 2003, five loudspeakers called MonoPulse »

hi>fi+ - August 2013. By Paul Messenger

Hi-Fi +“EQUIPMENT REVIEW: The MonoPulse Model S."

MonoPulse is one of Britain's smaller speaker makers, but it has been around for more than a decade, has a very distinctive range of speakers, enjoys a steady demand (especially from Scandinavia), and seems perfectly happy to remain a small operation.
The current line-up consists of three models – two floorstanders (A is for audiophile, S for slim) and one stand-mount (C is for compact). The £1 ,775/pair Model S is the smaller of the former, all of which share much in the way of technical features and physical presentation. In a business dominated by wood-veneered boxes, it's a pleasant change to find a cloth-covered speaker in a selection of colours.
Our examples came nearly all in black, decorated by cerise highlights. Most is cloth, though the back panel is leather and the top surface is a carbon-fibre panel; Just below the drivers, a matching badge embellishes the front.
Another distinctive (and welcome) touch is a carrying handle, usefully integrated into the back panel and facilitating moving the speakers around for best imaging and bass evenness.
Neater still in my view is the floor-coupling arrangement. Putting spikes directly into the base of a speaker as slim and shallow as this (18cm x 20cm) is a recipe for a knock-over disaster, which MonoPulse counters by means of a very neat arrangement using chunky steel outriggers. These are retracted for packing and transit, but each may then be pulled out to expand the footprint by slackening and re-tightening a couple of bolts. Thumbwheel-equipped spikes are then attached at the ends, ensuring a firm fix with no risk of stripping threads, and keeping the enclosure's port (that fires downwards through the base) clear of the floor.
Said port is tuned to a claimed 39H2, and worked fine under our conditions, but additional damping tubes are available FOC if required. The speaker is normally aligned for a listening 'window' about 90cm from the floor, though the spike heights may be adjusted to tilt this optimum axis slightly up (or down) to suit your favoured listening height.
The key technical feature here lies in offsetting the drivers with respect to each other and the listening zone.  The two drivers are electrically linked via what's described as a 'patented asymmetric' crossover network, the objective being to maintain accurate impulse synchronicity and precise musical leading edges through the crossover region.
The driver line-up consists of a 160mm (nominal frame diameter) bass/mid unit with a polypropylene cone, plus a 28mm fabric dome tweeter that operates above 3.5kHz and is fed via a fourth-order (24dB /octave) crossover network.
The accompanying leaflet might be brief, but it's very much to the point, and includes an unusual amount of useful advice.
The manufacturer's specified 87dB sensitivity is confirmed in our tests, which is a good figure in view of the speaker's fine bass extension to 25Hz (-6dB in-room).
The port output looks well damped and is tuned to 38H2, though the impedance also reveals a significant little peak at 210Hz, probably due to the vertical standing wave inside the enclosure.
In most respects the far-field averaged in-room response is rather impressive, though it's not particularly smooth, does tend to emphasise the higher frequency part of the spectrum. The Model S has a tonal balance that certainly favours low level listening.
It's certainly true that this presence 'forwardness' does offer certain advantages, especially in the way it makes speech unusually clear and intelligible even at very low listening levels. Despite a somewhat 'edgy' quality, it brings a welcome openness to the overall character, and there's no denying that one does adjust quite quickly to the departure from strict neutrality.
The manufacturer claims that this design delivers superior leading-edge definition, and I can't disagree with the assertion that the Model S has fine overall coherence, and in this respect is somewhat reminiscent of that achieved by loudspeakers using single full-range drivers. Stereo imaging is precise right across the soundstage, and even shows reasonable depth perspectives despite the forward tonal balance.
Dynamics could have more grip and a greater sense of drama, though in fairness this aspect of the performance is pretty typical of a speaker of this sensitivity and type. Much the same is true for the dynamic range, which is much as one might expect, but doesn't set any new records in this regard.
One obvious if perhaps somewhat surprising strength lies in the bass region, which is also impressively smooth, even and deep. This ensures that the speaker provides a firm underpinning to bass-rich material without any of the boomy exaggeration that is regrettably all too common, especially amongst modest port-loaded designs.
Sufficiently 'different' in both appearance and tonal balance, the MonoPulse Model S certainly justifies its existence in a marketplace that all too crowded with lookalike and soundalike clones. This is certainly not a speaker that's been designed either by committee or computer programme, and that alone must be a good thing.
The presence forwardness ensures plenty of explicit detail when playing at low late-at-night levels.  Add in the fine overall coherence, precise imaging and the even and extended bass and it all adds up to a very neat overall package. *

 

Go more Model S reviews »

HI-FI WORLD - May 2013. Timeline - MonoPulse refreshes its top-of-the-range, Model A loudspeaker.

"a wide stereo image and an almost holographic feel from the right recordings."

Hi-Fi World"On the face of it you wouldn't think there was much connection between loudspeakers and phased-array radar systems. Well, think again - or just have a chat with Allan Hendry. For it was Allan's work on radar equipment in the aerospace industry that started him thinking about loudspeaker design and how it could be improved.   It took him 10 years but he finally came up with his solution - and the MonoPulse brand was born.
Now almost a decade on from the launch of its first model MonoPulse has become an established brand and the revised A Model here sits at the top of its range. The design rests on Allan's belief in the importance of ensuring correct phase relationship between the drive units in loudspeaker design. ln the MonoPulses this is optimised through the precise positioning of the mid/bass and tweeter drivers and their integration through the crossover network to achieve genuine wave-front time-alignment through the entire audible frequency range.
The result is a distinctive-looking two-way floorstander which is claimed to offer remarkable coherence. The sturdy cloth-covered cabinets come in a range of colours with the 28mm high-frequency units now housed in new isolated carbon fibre casings in place of the previous rolled-steel fixings and set back at a precise distance on top of the unit to give that coherent sound wave.
Sturdy outriggers house extendable spiked feet to allow for optimum room and height positioning as well as optimising the action of the downward-firing reflex port.  Around the back the classy leather-clad panel sports a pair of bi-wireable speaker posts.
MonoPulse say the changes make no difference to the loudspeaker's sound - but add to the look and feel of the product.  They've also announced a substantial price reduction - knocking almost £800 off the list price to bring it down to £2,775.
SOUND QUALITY
The MonoPulses major on three attributes - timing, detail and stereo imaging.  Voices are especially well presented with a wide stereo image and an almost holographic feel from the right recordings. Barb Jungr's vocals on 'The Men I Love' floated serenely into the room with her distinct intonation and style portrayed admirably.  lt's a style the speakers seem to particularly thrive on as Sinead O'Connor sounded similarly impressive.
Transients are fast and clean - the MonoPulses giving the leading edge of notes a real zing. It can be a double-edged sword at times though. While good recordings shine, anything with a bright top end can tip over into undue brightness – Noel Gallagher’s guitar on Oasis' ‘Definitely Maybe' being a prime example.
Bass, however, goes commendably low with the port adding extra reinforcement to the eight-inch mid/bass unit. Charles Mingus walking bass lines came across well and the MonoPulses never sound stressed or as though they were reaching the extremes of their ability. The only criticism here was a slight degree of boxiness on some recordings - but again it seemed very recording-dependent
To get to their best they do need a good degree of free space around them – which helps the stereo imaging tremendously as well as giving a greater sense of air and space around the music. Designer, Allan Hendry suggests a good class A amplifier of at least 20 watts will get them working at their best and also says they are happy to work further apart than other similar-sized designs.
Experimentation with the height adjustable spikes is also hugely recommended. A slight adjustment can really help snap the image into focus and bring out the best in the MonoPulses. When that's done and with the right recordings they can produce an extremely cohesive and well-organised sound."

Go to more Model A reviews »

Mono & Stereo - Oct 2010. England holds quite a few unique audio jewels.

"Listening to MonoPulse S speakers leaves you in special harmonious mood."

"MonoPulse S speakers. England holds quite a few unique audio jewels that are many times hidden from us. There are quite a few amplifiers, speakers, cables and other accessories that are less known to the majority of audiophiles and music lovers. I wouldn't say that MonoPulse is not recognized. They have already got some accolades in the UK audio press, but I'm not sure they're known to the many of audio lovers worldwide.

Contemporary Art Deco? I've been in this never-ending audio quest of high-end for more than 20 years and seen many different designs and approaches to building speakers. Each speaker company holds in their products that special inherent view about sound, and through the medium of speaker design and functionality; they convey their language of music reproduction.
The MonoPulse S is a uniquely designed speaker. I'm not sure how exactly to describe the shape of it, but my final word would have to settle somewhere between future and retro. Contemporary Art Deco? Elegant use of materials and construction hides the real value of materials used and gives the S a kind of classic-timeless appearance. I always check aesthetics of new gear with my wife for a second opinion. She gave an instant nod to the elegance and freshness of the S speakers.

Class A friendly I will leave the specs to speak for themselves, but let me note just the 87dB efficiency. Minimal recommended power for tubes amp is 18 watts and for solid state around 35 watts. This puts them into very interesting position. 18 watts might not get you pure triode class A, but 35 watts of transistor power will open up the world of pure class A. Lately quite few of legendary companies are bringing back this topology and MonoPulse have a great advantage here.

From warm to neutral Leben CS300 is one of my favourite tube integrated amplifiers. The musical character that somehow transcends the typical sound we often connect with tube amplifiers pushes Leben into the more contemporary audio league, which is a good thing. MonoPulse S was simply sweet (but, not over sweet) in this combination. All the attributes that trigger my audio review sensors positively were there. Music never failed to come alive, and connection with performers was always on the reach of the hand. Switching to the Burmester 051 integrated amplifier pushed the sound a bit further in the realms of audio reproduction. Burmester 051 might be one of the most transparent solid state amplifiers in their price range and above. While there is some hint of Burmester in-house sound imprint of X-amp technology, it's still minimized to the maximum. MonoPulse S speakers gained some more neutral flow with the Burmester and lost the slight warmness of the Leben CS300. It might be discussed what's more natural, but the point here is that the S performed with the level of authority that I surely didn't expect from the speaker in this price range and from such a slim design. It shows that MonoPulse have really thought everything out carefully and made well balanced sound possible.

The hall effect What does it take to make speakers disappear? I guess many things. There are lots of theories on how to achieve this, but at the end the speakers speak for themselves. I just love to put all the pressure on the new gear under review with the Stefanovski/Tadić remarkable Treta Majka CD album. It instantly shows the quality of reviewed item with its unforgettable syncopated guitar attacks and the reflections of the sound created. Recording maestros have really outdone themselves with this recording, as Cowboy Junkies did with their Trinity Session. You simply cannot fail to judge the correct behaviour of speakers with these two recordings. I'm not talking gibberish sound-stage, detail, image etc., but the actual feel of the space, reverberation and atmosphere in connection with the music. Not saying I'm "grande experto", knowing how some particular album should sound or how it was recorded, but I can sense that aura and sensation of space surrounded in musical impact with my so called audio mileage and my experiences attending numerous live shows and concerts. It helps to balance my view with reviewing.
MonoPulse S conveyed the atmosphere, feeling of music, and surroundings were very involving and with recognized anchors (so to speak). The S speakers disappeared unlike many I have heard over the years. I’m not sure what is the exact reason or technical solution behind it, but they manage to fill out the room around them without giving out their exact position. Salute! This works great for stereo and I vividly daydreamed about surround setup with MonoPulse S speakers. This would make any videophile more than happy and fans of SACD recordings (for example 2L recordings) would jointly embrace them without much consideration.

Rhythm master With music, at least for me these past few years, what matters mostly is musicality and the way that review components connects me with certain music and performer. Normally technical specs must make sense and stand on their own, but they mean nothing without emotional connection. Rhythm, pace, micro dynamics, transitions even the "mojo" will always prevail in my perception and importance regarding music played through any reviewed gear. Most of the time (unless one has his own recordings and know the exact momentum of recorded situation) we simply don't know the exact conditions at which some album was recorded. What we can experience and revive (when the system is correctly set up) are the true emotions, impact of passion and energy being involved when creating or recording the music. Arguably live recorded music makes this distinction much easier, but there are many great musical recordings that captured the real spirit, rhythm and energy of performing artisans.

Conclusion Alongside remarkable disappearance of speakers, MonoPulse strikes you with rhythm and pace of the music that is rarely found in this price range At a few moments I would swear that its micro dynamics are coming from a horn based speaker. These two aspects alone are more than worth considering when you're in the need of new speakers. These are not full flagged large dynamic speakers like my listening reference Acoustic Preference Maestozo 2. MonoPulse never even try to be more then what they are. They succeed to marry the two above mentioned characteristic in such a way that it's both instantly captivating and hard to forget. Listening to MonoPulse S speakers leaves you in special harmonious mood, like long decayed notes from masterfully played piano maestro does. Don't bypass these speakers.

Go to more Model S reviews »

HI-FI CHOICE - July 2010. MonoPulse breaks the rules on stereotypes.

Fine 'sweet spot' focus and coherence, with good definition

Hi-Fi Choice"The basis of MonoPulse loudspeakers, lies in applying audio lessons that were learned worked with phased-array radar systems, the prime purpose being to reproduce transient leading edges accurately.
This imposes some constraints on the driver layout. These are solved by placing the inset tweeter beneath the mid/base drive unit. This goes some way to explaining the decision to go for a fabric covering over the front and sides of the enclosure. One worthwhile consequence is that the speakers are, therefore, available in a wide range of different colours, perhaps chosen to match carpeting or curtains. Alongside to fabric, the top 'hoop' is polished steel, again with colour options.
Despite its very slim appearance from the front, the £1,995 per pair Model S still has room for a 160 millimetre bass/mid driver with a visible (through the fabric) come diameter of 110mm. The tweeter has a relatively large soft-dome diaphragm.
The enclosure is reflex-loaded by a downward-firing port in the base, metal fet keeping the port clear of the floor, with or without the use of thumbwheel-tightened spikes. Electrical connection is via twin terminal pairs.

Sound quality.
Sitting in the prime listening position, I was very impressed by the sound quality of the Model S. The MonoPulse is deliberately designed as a 'sweet spot' loudspeaker, and will, therefore, show expression and time coherence in a relatively small listening zone. Imaging is impressively spacious, with excellent focus and coherence.
Different in nearly every respect from the stereotypes, the MonoPulse Model S has unusual styling and presentation and its sonic performance orientated towards a sweet spot listener. It certainly represents an interesting alternative.

Go to more Model S reviews »

HI-FI WORLD - May 2010. One Shout - A major upgrade of the Model S.

"MonoPulse's Model S has had a major upgrade."

Hi-Fi World"It has now been optimised for use with valve amplifiers, particularly using vinyl sources.

The 8 ohm minimum impedance, touched five times across the frequency spectrum, gives an easy and balanced drive, while the 30kHz top end response is perfect for the wide bandwidth of modern vinyl.

The 300 watt maximum power handling means they also show grace under pressure."

Go to more Model S reviews »

Hi-Fi News - April 2010. Restored Pulse.

Major upgrade to MonoPulse Model S.

Hi-Fi News"MonoPulse's Model S has witnessed some key upgrades.

The top-end frequency response now extends to 30kHz while the load impedance in made easier, touching a minimum of 8 ohms across the entire bandwidth. This is all in aid of furthering the speaker's compatibility with lower-powered valve amplifiers.

On the other hand, the Model S now enjoys a higher 300 watt maximum power handling, ensuring it's just as suitable for use with substantial solid state amps.

Cake all round..."

Go to more Model S reviews »

WHAT HI-FI - Awards 2009. Best of both worlds?

Five stars

Model A wins top, five star, award. "fabulously, uniquely brilliant."

What Hi-Fi"MONOPULSE IS serious about its timing. The company's idea is to get the leading edges of all notes, from the entire frequency range, to the listener at the same time.
It's what single-driver speakers are famed for, but MonoPulse uses two precisely placed drivers in conjunction with a specially designed crossover to create a 'single impulse wave front'. The result should be a rhythmically seamless presentation. It is.

"Astonishing precision results in excitement by the bucket-load"

Play the scuzz-rock/disco-pop mix of Marmaduke Duke's Everybody Dance and the 82As astonishing precision results in attacking excitement by the bucket-load. Every note begins with pinpoint precision, but there's no sacrifice in texture or natural note degradation - these aren't clinical to the extent of sterility.

A joyful presentation

The As are chunky and full-bodied with sensational bass punch, depth and definition. Vocals are equally impressive - full of life and nuance.

The overall presentation has excellent width and three-dimensionality. Dynamics, both small-scale and large, are a joy, and although the rhythmic integration of instruments is seamless, it doesn't prevent separation in the soundstage, allowing you to identify individual strands with ease.

The As combine the best of a single-driver with the best of a more traditional multi-driver array. But care is required with positioning. MonoPulse recommends that 85cm between each speaker and a wall. We'd add that toeing them out a little more than usual helps them sound their best.

If you expect manufacturing perfection, walk away. But if you can overlook the odd flaw, and are happy with the materials, the MonoPulses are fabulously, uniquely brilliant.

Go more Model A reviews »

WHAT HI-FI - July 2009. Model A grips and controls information like the Stasi.

Precise speakers with a wide range of talents, timing being the most immediately impressive.

What Hi-Fi"THE MonoPulse As' specification (28mm soft-dome tweeter decoupled from the rest of the cabinet, offset mid/bass driver on the front panel, in a quest for class-leading time alignment) looks exiting.

Marmaduke Duke's Heartburn is a rapid, clattering test of timing and detail resolution, but it's meat and drink to the MonoPulses. The soundstage the As present is open, expansive and utterly coherent, and they present the song in fast, fluent and rhythmically adept measures. They're unflustered by dynamic shifts and, thanks to a midrange that's fluid and expressive, grant singers all the anima they require. Low frequencies may not have the out-and-out extension of some, but they're punchy, controlled and tonally articulate.

Superb sound

The real party piece, though, is the way the As enter individual notes and sounds - these speakers grip and control information like the Stasi, and have the precision to make a tune as unruly as Four Tet's Wing Body Wing sound organised and cohesive. As a listen they're endlessly satisfying.

Go to more Model A reviews »

WHAT HI-FI - Ultimate Guide March 2009. MonoPulse Model S, five star holder.

Five stars

What Hi-Fi"MonoPulse is a company dedicated to an idea. While some speaker manufacturers concentrate on creating a certain kind of frequency response, MonoPulse concentrates on timing."

What is timing? Well, if one driver is moving forward and the other moving backward at exactly the same instant, the ‘leading edge’ information of each sound – some in the frequency range of one driver, some in the range of the other – will hit your ears at different times.

If you can only do one thing...

MonoPulse says it has designed a speaker in which the drivers move in absolute unison. And it’s worked.

In terms of timing alone, the Model Ss are almost ridiculously good. Music is delivered with sublime rhythmic precision, a shapely sense of phrase and beat that makes other loudspeakers sound blurred and hazy by comparison.

From the jangly ‘60s inflections of The Shins’ Wincing the Night Away to the testosterone-fueled bombast of Nick Cave’s side-project Grinderman, the S’s vibrancy, accuracy and rhythmic presence is extraordinary enough to warrant five stars on its own.

So the Monopulse Ss are not a typical, jack-of-all-trades all-rounder. If you were feeling cynical, you could say they simply do one thing well – but in the sense that Jimi Hendrix did one thing well.

They do that one thing so staggeringly well that you could spend years enjoying that one talent.

In short, these are great speakers.

Verdict. If you didn't know how critical timing is to a speaker's performance, the 32Ss will show you."

Go to more Model S reviews »

WHAT HI-FI - December 2008. Pulsating Floorstanders really do rock our world.

Five stars

Model A wins top, five star, award. "Add class-leading sound staging to the plus points"

What Hi-Fi"WHAT MAKES THE Model As special? Well, the MonoPulse name gives a clue. The company's big thing is about responding to the leading edge of notes as accurately as possible.

To this end these floorstanders use an unusual configuration of crossover and have offset drive units to aid time alignment - the 28mm soft-dome tweeter is on top of the cabinet, the 20cm mid/bass sits conventionally on the front panel. The idea is that both drivers move together at every transient, giving a more precise, coherent sound wave.

Notes of many colours

Other technical highlights include a metal hoop supporting the tweeter (keeping it clear from vibration) and damping the wooden cabinet's sides. Another metal piece controls the front panel's movement.

There's a choice of colours for the cloth finish, and the metal can be painted to match or contrast.

When it comes to timing, detail resolution and stereo imaging, the As have little to fear from any rival. These MonoPulses are immensely musical speakers that latch onto a rhythm track with breathtaking confidence.

Strange looks, super sound

All that time alignment work pays off handsomely , with cohesive and well-organised sound that captures the start and end of notes with real precision You can add fluid dynamics and class-leading sound staging to the plus points, too. The wide-ranging talents mean the As are as happy charging along to Grinderman as they are replaying something subtler (and grander) such as Mahler's Symphony No1.

These MonoPulses are strange-looking speakers. But give them a chance with suitably talented electronics and we have no doubt they'll produce some of the most musically satisfying results around.

Verdict. Odd appearance apart there's an awful lot to like about these MonoPulses. Make sure you give them an audition."

Go to more Model A reviews »

HI-FI CHOICE - December 2008. MonoPulse Model S speakers revised.

Stereo images are well formed and focused

Hi-Fi Choice"Allan Hendry's MonoPulse loudspeaker designs were developed by applying lessons he learned when working on phased array radar systems. The decision to go for a fabric covered presentation was probably made to help achieve the required time alignment between the drive units, which imposed significant constraints on driver disposition. The use of fabric allows the speakers to be available in a wide choice of different colours, while the back is covered in a thin foam sheet.

MonoPulses come in two distinct ranges, the larger A Models, and the more compact S Models. We originally reviewed this pair of Model Ss in issue 304, with somewhat mixed results, but it has since undergone some revision and so has returned for an update.

Despite its very slim appearance from the front, the S still has room for a 160mm bass/mid driver with a large diameter voice coil. The main tweeter has a relatively large 31mm soft dome diaphragm.

In the interests of time alignment, the main driver is mounted above the tweeter here, and the enclosure is reflex-loaded by a downward firing port in the base. Metal feet keep the base clear of the floor. Alternative length spikes (or indeed no spike at all) allow some re-tuning of the port frequency, which might be useful. Electrical connection is made via twin terminal pairs.

SOUND QUALITY

Generous in-room output from the port means the MonoPulse 62S is is better kept clear of walls. Otherwise the overall tonal balance is neutral.

Happily our criticism of the original (that it was too laid back to the point of sounding rather shut in through the presence band) no longer applies. As a result the 62S now has the fine crossover zone coherence that makes the larger models in the MonoPulse range such an interesting proposition and the overall sound now has a much more neutral voice band.

It's not the most dynamic speaker around but it is relatively smooth and lucid. Reflecting the fine coherence, stereo images are well formed and focused. The modifications have significantly improved the S.

Go to more Model S reviews »

HI-FI WORLD - October 2008. Pulse Rate - A review of the Model A.

"a fabulously integrated big and relaxed sound."

Hi-Fi World"There are many different schools of thought when it comes to loudspeaker design. Some believe that the drive units are the be all and end all, others say that the cabinet is the most important, another group point out the crossover as the make or break item, and a few individuals on the lunatic fringe believe that none of this matters as long as the drivers are strung together with cable that costs as much per metre as crude oil per barrel currently!

No matter which school of thought you subscribe to however, there is a general trend towards using one or all of these ideas to set up and modify a desired frequency response, with the general idea to get it as flat as possible, maybe with the odd spot of judicious tweakery here and there according to the design requirements, or the designers preference. One or two designers take a slightly different approach, however...

Allan Hendry of MonoPulse is such a designer. A hi-fi enthusiast since his early days, Allan worked in the aerospace industry for years designing phased-array radar systems, and it was this work that made him think about loudspeaker design and in particular the necessity of phase coherence from the drive units. Allan investigated the impulse response of a wide range of loudspeakers in a variety of situations and came to the following conclusions; firstly, that it was vital to time-align the treble and bass drivers in order that an impulse sent to both drivers would arrive simultaneously at a measurement microphone set in front of each unit (and therefore, at the listeners ears); secondly, that the connection of tweeters out of phase to compensate for the phase inversion of a second order crossover network causes more problems that it solves and, finally, that maintaining phase coherence in a loudspeaker becomes more difficult the more drive units you add.

With this in mind, he picked up pen and paper and the result is the MonoPulse range of loudspeakers, with the name being a nod towards the impulse-correct designs he intended to create. At the moment, there are two models on offer (plus matching centre channel and rear surround items) - the Model S series and the 'Audiophile' Model A which uses an 8" (200mm) main driver with a Kevlar cone and a four layer voice coil, together with a 28mm tweeter claimed to extend to 30kHz.

The A's design crosses over to the tweeter at 4kHz. In keeping with the time domain accuracy, the crossover uses a second order filter on the bass driver, but a fourth order design on the tweeter. Most interesting however is the cabinet, which is an MDF case fitted inside a rolled steel 'hoop' and isolated from it using a "high-hysterisis-loss polymer. The tweeter is suspended separately from the top of the hoop, isolated it from the main driver and cabinet, and set back by the time alignment. A steel damping bar is fitted to the front of the cabinet, and can be located outside as a styling feature, or tucked away inside if you prefer.

The cabinet itself is covered with cloth which is available in ten different colours, including Black, two different Blues, Red ,Green and Burgundy. The steel hoop can also be specified in Gunmetal, Black, Sand, Bronze or Burgundy. Build quality is very good and I personally like the styling but am less sure about the Dark Chocolate/Metallic Bronze colour combo that editor DP requested for the review (albeit unsurprising if you've seen his shirt collection). The rear of the main cabinet and the tweeter are covered with black foam, and two pairs of terminals allow for bi-wiring duties.

Finally, the As are supplied with spikes that fit into the feet and are sufficiently long to allow some experimentation with spacing of the loudspeaker from the floor, which will alter the behavior of the downward firing port. MonoPulse point out that setting them shorter gives more emphasis and less extension, and vice versa, which is useful for taking different flooring materials and thicknesses into account. Vital statistics are 1080x230x250mm(HxWxD) and 22kg per loudspeaker. "

SOUND QUALITY
A decently sized main drive unit usually means a decently large soundscape and this is indeed the case with the MonoPulse Model As. Their eight inch bass/mid unit endows them with a lovely, properly grown up sound that gives the bass and midrange a great sense of depth, ease, warmth and detail. That is not to say that the 42As are all soft, warm and fluffy at the low end as they certainly are not - bass lines were deep, confident, pacy and blessed with fine rhythmicality. However, whereas some designs with smaller drive units can give a similar effect with an underlying sense of 'see how hard I'm working to give you all this!' the 42As never seemed under duress.

Another most notable feature of the Model A's performance was their transient response. Allan's work on the phase coherence of the design has resulted in a loudspeaker with no hesitancy or wallow. Big-sounding unstressed loudspeakers can often be rather flabby in timing terms but not so the As; drum strikes are swift and snappy, bass guitars are detailed and well defined, and every instrument stands out from its cohorts. Although the image generated by the MonoPulse does not quite envelope the listening area from side to side in a way that some designs can, they still have a fine sense of spaciousness between them, and order everything very neatly in this space. Additionally, they do give fine front to back depth to the proceedings.

Mating a larger unit to a single tweeter can often be a hit or miss affair but MonoPulse has done well here. There is no sense of disjointedness between the two drivers and the As have a well defined and crisply spry top end.

CONCLUSION
In a world of loudspeakers populated by the equivalents of high-revving four cylinder engines, the MonoPulse As are a relaxed and smooth V8. They have a fabulously well integrated and big, relaxed sound that is also well defined, yet one that times with positively metronomoic precision. These are rare qualities to find together in one loudspeaker and, as a result, the As are something of a breath of fresh air into the loudspeaker market. combine this with their easy load and wide range of intereor-friendly finishes and they make a very strong case for themselves. Well worth checking out.

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HI-FI CHOICE - August 2008. MonoPulse Model A speakers offered as prize.

MonoPulse Model A loudspeakers worth £3,445!

Hi-Fi Choice"Monopulse hand builds all its loudspeakers, to ensure the product is bespoke as possible. But it's not just about hand-built cabinets and fancy finishes; MonoPulse supremo Allan Hendry worked with pulsed phased-array radar systems before retiring and concentrating on his first love, loudspeaker design. All of which means the MonoPulse designs are packed full of innovative, clever technology, the kind that wins Ultimate Group Tests in fact.

The MonoPulse has abandoned the conventional wooden cabinet, using an inverted-U of steel for the sides and top of the speaker. While the large 218mm bass driver and 28mm Morel tweeter on different time-aligned baffle boards.

When we reviewed the A in HFC 302 we gave it a richly deserved deserved Best Buy thanks to its fine performance, coupled with excellent dynamic headroom. And, as you might expect from such a phase-corrected loudspeaker, the temporal coherence was superb.

Go to more Model A reviews »

Hi-Fi News - July 2008. Colourful Bargain.

Stylish MonoPulse improved.

Hi-Fi News"Striking British loudspeakers from MonoPulse are now improved as power handling rises. The flagship Model A, at £3,445, has its maximum power increased to 550W.

The company also announces stylistic changes to reduce the 'boxy' appearance. Rounded front corners and slight features at each side have been added."

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HI-FI WORLD - July 2008

PULSE ON THE WIRE.

Hi-Fi World"News comes to us of MonoPulse's revised Model A loudspeaker, a striking looking design that has just been improved. Power handling is upped to 300W RMS, whilst the cabinet is revised - with a more angled appearance and rounded corners. What is retained are the ferro-fluid cooled HF units separately, mounted on the quarter-inch-thick rolled-steel surrounds, which are then clamped via high-hysteresis-loss polymer, to all-bonded cabinets."

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HI-FI CHOICE - March 2008. Elegant MonoPulse Model S. £1,995 per pair.

Compact speaker owes much to its larger siblings

Hi-Fi Choice"Despite (or because) it has dared to be different, new kid on the block MonoPulse, has succeeded both in presentation and engineering.

The application of phased array radar principles to loudspeaker design might seem unusual, but it has been the core foundation of the company's approach. No doubt, due to the fact that this was the field in which principal Allan Hendry spent much of his working life.

Applying this to loudspeaker design imposes significant constraints on driver distribution, which in turn is probably responsible for the the decision to go for a fabric-covered presentation with metal embellishments, which also allows for a wide choice of ten different colours.

MonoPulses come in two distinct forms, the much admired larger Model A and the more compact Model S.

Despite a width of only 170mm, MonoPulse has managed to squeeze a 160mm mid/bass driver with large diameter voice coil into the floorstanding enclosure.

In the interest of time alignment, the main is mounted above the tweeter and is reflex loaded by a downward-firing port in the base. Metal spikes keep the port clear of the floor, with or without the use of thumbwheel-tightened spikes. Electrical connection is made via twin terminal pairs. The main tweeter has a relatively large 28mm silk dome diaphragm.

Room measurements indicate - and listening tests confirm - that the 62S is best kept clear of walls. The good news is that it delivers a fine performance through the bass and broad midrange. It's not the most 'grab you' sound, but it is relatively smooth and lucid, with a satisfying weight and drive. The bonus of presence restraint is that it does mean the speaker avoids sounding aggressive and likes to be played with a bit of volume.

"LAB REPORT. Happily the bass extends usefully down to 30Hz or so, with the port tuned to 45Hz, and the amplifier load looks relatively easy to drive.

"VERDICT. This exceptionally elegant floorstander uses a waveguide to reduce the crossover frequency and improve voice integrity. The result is lively, with a sweet top end and fine coherence when carefully sited.

Go to more Model S reviews »

HI-FI CHOICE - January 2008. Best Buy. MonoPulse Model A. £3,445 per pair.

Unconventional loudspeaker design is the name of the game

Hi-Fi Choice"It's less than five years since we first encountered MonoPulse, as a relatively new brand with a number of interesting and unconventional ideas about loudspeaker design.

Patron and hi-fi enthusiast Allan Hendry, worked for many years on pulsed, phased array radar and, after his retirement, applied his appreciation of the importance of phase relationships to loudspeaker design. These applied especially to the relative positioning of the drive units and their integration through the crossover network, in order to achieve genuine wavefront time-alignment through the entire region.

The styling is very original and striking, with a wide steel wrap in the shape of a tall inverted-U forming the sides and top and firmly bolted onto the outside of a fabric-covered wood-composite enclosure. This is also wide enough to accommodate the relatively large diameter 218mm bass/mid driver, while a reflex port is fitted into the base of the enclosure, firing downwards and held 4-5 cm off the floor by some purposeful and well-seated spikes.

The enclosure is roughly the same depth as its width, so the footprint is quite modest, but the hefty 28kg weight guarantees good physical stability.

As part of the time alignment, the two drivers are mounted on separate baffles, so the bass/mid driver fixing is slightly nearer listeners than the Morel sourced 28mm soft domed tweeter. This also provides mechanical and acoustic isolation between the drivers.

Although our sample came in a sober combination of metallic gunmetal and slate, the steel wrap and the two separate grille cloths are also available in a variety of colours. The lower part of the front panel was fitted with an offset metal damping strip that adds £100 to the price. Signal connection is made via twin terminal pairs, allowing for adventures in bi-wiring or bi-amping.

SOUND QUALTY. The Model A requires free space siting to deliver the best bass alignment, with the time-aligned crossover and precise drive unit spacing responsible for the remarkably impressive coherence, especially through the voice band, which seems to be MonoPulse's particular stock in trade. This in turn helps to sharpen the image focus and precision, more accurately and convincingly defining the position of a performer in space.

That's by no means the A's only strength. The large main driver helps deliver fine performance through the bass and mid band, with good overall balance and ultimate bass extension.

Best of all is dynamic expression, which is comfortably ahead of the pack and further enhanced by the superior timing and across-the-band time coherence.

LAB REPORT. Sensitivity is a pretty generous 90dB.

VERDICT. Splendid dynamic expression and wonderful time and coherence. Fine bass to mid balance and dynamics. Remarkably impressive coherence through the voice band.

(In this group test the MonoPulse Model A, with an 88% score, was well ahead of the 80% scored by the more expensive Dali Mentor 5.)

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WHAT HI-FI - Ultimate Guide 2007. MonoPulse Model S, five star holder.

Five stars

What Hi-Fi"MonoPulse is a company dedicated to an idea. While some speaker manufacturers concentrate on creating a certain kind of frequency response, MonoPulse concentrates on timing."

What is timing? Well, if one driver is moving forward and the other moving backward at exactly the same instant, the ‘leading edge’ information of each sound – some in the frequency range of one driver, some in the range of the other – will hit your ears at different times.

If you can only do one thing...

MonoPulse says it has designed a speaker in which the drivers move in absolute unison. And it’s worked.

In terms of timing alone, the Model Ss are almost ridiculously good. Music is delivered with sublime rhythmic precision, a shapely sense of phrase and beat that makes other loudspeakers sound blurred and hazy by comparison.

From the jangly ‘60s inflections of The Shins’ Wincing the Night Away to the testosterone-fueled bombast of Nick Cave’s side-project Grinderman, the S’s vibrancy, accuracy and rhythmic presence is extraordinary enough to warrant five stars on its own.

So the Monopulse Ss are not a typical, jack-of-all-trades all-rounder. If you were feeling cynical, you could say they simply do one thing well – but in the sense that Jimi Hendrix did one thing well.

They do that one thing so staggeringly well that you could spend years enjoying that one talent.

In short, these are great speakers.

Verdict. If you didn't know how critical timing is to a speaker's performance, the 32Ss will show you."

Go to more Model S reviews »

Hi-Fi News - August 2007. Slim City. MonoPulse Model S.

If you're looking for a speaker to take you direct to the core of the music, few rival this revamped MonoPulse at the price.

Hi-Fi News"Significantly smaller than previous models - 910 x 170 x 205 (hwd), the Model S lacks MonoPulse's rolled steel cabinet hoop, the only vestige of which is a short, wide channel atop the cabinet.

The Model S uses a 160mm Audax Kevlar-coned bass-mid driver (which has adhesive pressed between the back of the pressed steel chassis and magnet assembly to enhance the unit's ruggedness and possibly suppress structural resonances); and an aluminium voice coil, strontium magnet, silk dome tweeter; which is claimed to extend the response out to 30kHz.

In order to achieve time alignment of the drivers along a slightly uptilted listening axis (to suit typical seated ear height), the bass/mid driver is located above the tweeter - an arrangement we don't see so often today but was once popular, for example, with Mission.

The cabinet is constructed of 18mm MDF, with no internal bracing, and - like all MonoPulse's - has a downwards-firing reflex port.

Comprising three air-cored inductors and three film capacitors, the crossover network - which, as always with MonoPulse, puts design emphasis on impulse response - is hard-wired to the back of the input terminal plate. Separate low-pass sections (to the mid/bass unit) and high-pass sections (to the tweeter) are accessible via two pairs of input terminals with gold-plated links.

What earns it a place in my my affections is its essential lucidity and vitality."

Go to more Model S reviews »

HI-FI CHOICE - August 2007. MonoPulse Model S

MonoPulse's new baby features its unusual crossover and styling

Hi-Fi Choice"Relatively young as hi-fi companies go, MonoPulse was founded by one Allan Hendry who spent much of life in electronics working on pulsed, phased array radar systems, and then decided to to apply the knowledge he'd gained to his lifelong passion for hi-fi and loudspeakers.

The relevance of radar to loudspeaker design may not be immediately apparent, but Allan is particularly conscious of the need to maintain the correct phase relationships between the bass/mid driver and the tweeter through the crossover region, in order to reproduce the leading edge of an impulse accurately, and that's reflected in both the crossover network design and in the unusual way the drivers are positioned and spaced.

The MonoPulse stereo models come as the Model S and the Model A. Both eschew the usual real or imitation wood finish: the S Model is clad all over in cloth, with ten different colour options available, from the sober to the mildly outrageous, while the Model A combines cloth with a substantial contrasting steel hoop. Our Model S came in Cranberry - a sort of pastel magenta - which is certainly unusual, but rather attractive.

The Model S has a 160mm frame, Kevlar-cone main driver. The tweeter is a 28mm soft dome device, mounted quite low down, below the bass/mid driver.

A reflex port into the base of this enclosure, and held an appropriate distance off the floor by little feet with spikes. The small main driver enables the enclosure to be very slim. Connection is made via twin terminal pairs.

MonoPulse places its main emphasis on maintaining integrity and phase coherence through the crossover region, and it's true that the Model S is largely successful in this respect. Voices - both speech and singing - sound impressively vivid, coherent and expressive, highlighting the accents and tonalities of different individuals in a most persuasive way."

Go to more Model S reviews »

WHAT HI-FI - May 2007, giving the Model S their top, five star, award.

Quicken Your Musical Pulse.

What Hi-FiMonoPulse is a company dedicated to an idea. While some speaker manufacturers concentrate on creating a certain kind of frequency response, MonoPulse concentrates on timing."

"What is timing? Well, if one driver is moving forward and the other moving backward at exactly the same instant, the ‘leading edge’ information of each sound – some in the frequency range of one driver, some in the range of the other – will hit your ears at different times."

"MonoPulse says it has designed a speaker in which all the drivers move in absolute unison. And it’s worked. In terms of timing alone, the Model Ss are almost ridiculously good. Music is delivered with sublime rhythmic precision, a shapely sense of phrase and beat that makes other loudspeakers sound blurred and hazy by comparison."

"From the jangly ‘60s inflections of The Shins’ Wincing the Night Away to the testosterone-fueled bombast of Nick Cave’s side-project Grinderman, the 32S’s vibrancy, accuracy and rhythmic presence is extraordinary enough to warrant five stars on its own."

"So t he Monopulse Ss are not a typical, jack-of-all-trades all-rounder. If you were feeling cynical, you could say they simply do one thing well – but in the sense that Jimi Hendrix did one thing well."

"They do that one thing so staggeringly well that you could spend years enjoying that one talent."

"If timing is your main musical concern, you simply have to check these out."

"Verdict. Extraordinary powers of timing and resolution; available in more than ten colour combinations. If you didn't know how critical timing is to a speaker's performance, the Ss let you know explicitly." Five stars

Go to more Model S reviews »

HI-FI CHOICE - July 2006. MonoPulse Model A awarded Best Buy.

MONOPULSE MODEL A

Hi-Fi Choice"The man behind MonoPulse, hi-fi enthusiast Allan Hendry, spent much of his working life on pulsed phased-array radar systems. This has made him particularly aware of the importance of phase relationships. He’s applied that understanding to his loudspeakers, using the geometry of the enclosure as well as the design of the crossover network to maximise the phase coherence through the crossover zone."

"All the MonoPulse models are two-ways, and all share the same very radical – some might say rather strange – styling. This is both original and striking. The dominant feature is a hefty steel wrap that forms an inverted-U around the sides and top – the latter portion provides the mounting for the separate and set-back tweeter baffle, while the whole adds mass and stiffness to the bass enclosure. Eye catching and, as it turns out, effective."

"The Model A has a generous bass/mid driver which features a large diameter voice coil that confers exceptionally high power handling. The bass enclosure is heftily constructed in MDF and covered in a wide choice of coloured fabrics; an additional layer of foam covers the back panel."

"A reflex port fitted into the base is held several centimetres off the floor by some very well founded and purposeful spikes, and the whole thing feels very solid and stable. The two drivers are mounted on separate baffles, so the bass/mid driver sits slightly nearer listeners than the 28mm soft dome tweeter. Connection is made via twin terminal pairs, allowing for bi-wiring or bi-amping."

"SOUND QUALITY. The first thing one notices when placing and connecting up the Model A is just how coherent and ‘real’ it sounds. It might not match the strict tonal accuracy and neutrality of some of its immediate competitors, but no time-smear, combined with a vigorous dynamic delivery, provides more than ample compensation. MonoPulse uses the phrase ‘transient synchronism’ to describe its particular strength, and that’s as good as any to describe the crispness and clarity with which individual instruments are defined."

"Timing is truly exceptional, and percussion in particular is notably well defined, making even drum solos unusually entertaining and musical! And the Steve Reich-like vibraphone work on Sufjan Stevens’ Come on Feel the Illinoise is notably deft and clear."

Go to more Model A reviews »

Hi-Fi News - February 2006. By Keith Howard.

Current Affairs.

Hi-Fi News"In 20 years nobody has tried to verify if speakers draw unexpectedly large currents on music signals."

The MonoPulse is even better behaved, with no excess current episodes recorded on either music tracks."

hi>fi+ - December 2005. By Paul Messenger

Hi-Fi +“EQUIPMENT REVIEW: The MonoPulse Model A Loudspeaker."

"I doubt many listeners will have encountered MonoPulse, as it’s a relatively new operation, and consequently still has only limited distribution. It’s yet another start-up company hoping to achieve success in a crowded loudspeaker marketplace, but at least this is one example that includes much more than its fair share of originality."

"The man behind the brand is Allan Hendry, a hi-fi enthusiast of long-standing, but one who has spent much of his working life as an engineer working in the field of pulsed, phased-array radar systems. That background, in which phase relationships and coherence are a prime ingredient, provided the inspiration to experiment with loudspeakers, and to try and achieve a design which placed the maintenance of phase linearity high up the list of priorities, including the problematic crossover transition. The ultimate consequence was the decision to manufacture the range of MonoPulse loudspeakers for commercial sale."

"The range today basically consists of two models, code named Model S and Model A, both based around a common engineering theme but growing progressively larger. The 20 litre Model S was the first to come to my attention, some two and a half years ago, and about six months back I tried the larger 40 litre Model A for the first time. Both impressed me a great deal with the sheer vividness of their music making – “the shock of reality” was how I described that original Model S."

"For all its virtue, I did have one or two criticisms when I initially tried the Model A. Allan has taken these on board, and made a minor crossover change to increase the relative treble output by about 1.5dB. He has also recently increased the price to £3,445/pair, though the speaker remains decent enough material value for money, irrespective of sound quality judgments."

"The cosmetics are very unconventional. Our samples came finished largely in black cloth, with grey foam covering the back and a silver steel inverted-U wrap reinforcing the sides; a wide variety of options, including a choice of ten colours for the full height grille, are available. The basic carcase is MDF, almost square in plan cross-section, and the whole thing is damped and reinforced by the etched, rolled steel wrap. This is 7mm thick and 100mm deep, and undoubtedly contributes to the very solid build and 28kg total weight."

"A vibration-damping steel bar is set into the front panel, either inside or outside the grille, to break up that panel’s main vibration mode."

"The whole thing sits on little steel feet that accommodate 8mm spikes and keep the ported base clear of the floor. Although it’s quite tall and not particularly deep, the whole thing feels reassuring stable. In engineering terms this is a large, 40 litre two-way, port-loaded through its base. It has a 200mm bass/mid driver – significantly larger than today’s norm. This uses a moulded frame and doped paper cone, and is positioned vertically very close to the 28mm fabric dome tweeter. The latter is mounted on its own sub–baffle, set back by a small but precise amount, in order to establish the precise phase integrity."

"The spec claims a generous sensitivity of 90dB, alongside an easy (minimum 7 ohms) amplifier load. Both these claims were confirmed on test, indication that this speaker should make a find partner for low power valve amps. The port is tuned to 37Hz, which should ensure good ultimate bass extension. The bass alignment favours keeping the speaker clear of walls, and the overall bass level is a little dry, but that’s partly because the mid-band is just a little too strong. And if the treble output was a little too restrained when I first checked this speaker out, it seems just about ideal now. The Model A doesn’t deliver the smoothest sound around, but it is pretty well balanced overall, and the vital crossover transition is handled impressively well."

"When assessing a loudspeaker, it’s always difficult to ascertain just how much of the sound it makes is down to the inevitable balance anomalies – there’s no such thing as a truly ‘flat’ loudspeaker. The A does have a measure of mid-band emphasis, to be sure, but that doesn’t disguise the remarkable immediacy of a performance that clearly has minimal time-smear and fine transient integrity. MonoPulse calls this aspect of the performance ‘transient synchronism’, which is as good a buzz-phrase as any for something that really does bring a crispness and a very welcome dose of realism to the proceedings."

"Furthermore, by preserving good leading edge integrity, dynamics somehow seem to sound punchier and more believable. In some respects I am reminded of the very special immediacy that one finds with speakers using single full range drivers, and if the 42A doesn’t go quite that far in terms of absolute coherence, it doesn’t sacrifice performance at the frequency extremes in the way that single-driver systems invariably do."

"If superb transient integrity is its main claim to fame, there’s very little to criticise elsewhere in the performance. My original complaint of some lack of treble has been entirely overcome, and the whole mid-to-treble balance and transition now sounds beautifully smooth and well ordered. Perhaps the most obvious consequence of the mid forwardness is a perception that the bass end is a shade lacking in weight, warmth and authority, though there’s plenty of deep bass extension here, and output throughout the bass region is relatively smooth and even. There are some ‘paper cone’ and ‘cupped hands’ artefacts, most audible with speech, but in my experience the subjective consequences of colouration are much less obvious in a speaker like this, where time-smear and overhang are both very well controlled."

"Interestingly, and tending to confirm the claims regarding superior phase coherence, the image focusing is very sensitive to head position, rather in the manner of panel speakers. If imaging’s your thing, take extra car in setting up these speakers, making sure they’re truly vertical, similarly oriented and exactly equidistant from your listening seat. The payoff makes the effort well worthwhile."

"The very essence of this speaker is simply that it makes listening to any source unusually easy and interesting. Speech is very intelligible, even at low listening levels, and individual accents and inflexions come through very clearly. Music sounds beautifully coherent and free from artifice, so that one is rarely conscious of any intrusion from the speakers themselves, while the brain focuses instead on the subtlety and delicacy of the music making process. All kinds of music seem well served, the 42A proving just as adept at conveying the texture of orchestral strings as it is with punchier and more percussive pop and rock material – indeed, drum solos come across as particularly convincing."

"I daresay the cosmetics will not find universal favour. In a marketplace dominated by a stereotype that comes clothed in a choice of real wood veneers, a speaker wrapped in polished steel over a cloth background will always look a little strange. And the lessons of history suggest that we tend to be a rather conservative lot when it comes to choosing loudspeakers. But those who take the trouble to audition this MonoPulse design could well find themselves seduced by the sheer speed and integrity of its music making and the sheer dexterity with which it handles the most complex material."

"This is a genuine audiophile product at a very realistic price.”

Go to more Model A reviews »

WHAT HI-FI - December 2005, giving the Model S their top, five star, award.

Get your finger on the 'Pulse.

What Hi-FiIf your first thought was 'MonoPulse who?', you're not alone. This is the first time we've come across this manufacturer, and we're glad we did."

"Don't worry if the blue cloth/silver metal look of our pair isn't to your taste, because the company is flexible when it comes to colours. Build is fine, but these speakers lack some cosmetic polish compared to industry majors. But that's where the negatives end"

"Dynamics and detail impress. MonoPulse puts a great deal of emphasis on getting the phase accuracy between the mid/bass and the tweeter spot on. It's succeeded, with the result that Ss latch on to the leading edge of every note with breathtaking confidence."

"They time superbly, and can deliver a complex rhythm track such as Gorillaz's Dirty Harry in as surefooted a manner as any speaker at this price. Detail is impressive and dynamics vivid. Carefully matched, the Ss give the class champions something to think about."

"Verdict. Great for the money. A fast, dynamic sound; tracks rhythms superbly; fine integration between the drive units. Five stars

Go to more Model S reviews »

HI-FI CHOICE - September 2005. MonoPulse Model A, by Paul Messenger.

Unusual in every respect, does MonoPulse challenge stereotypes?

Hi-Fi Choice A relatively new name on the scene, MonoPulse loudspeakers were conceived and created by hi-fi enthusiast Allan Hendry, who spent much of his professional life working in pulsed-array radar systems. That experience made him particularly conscious of the importance of phase relationships, and he’s subsequently applied that know-how to the integration of bass/mid driver and tweeter through the crossover region."

"The result was the creation of a range of MonoPulse loudspeakers. We reviewed the first of these, the MonoPulse Model S, in HFC 245 two years ago, and with very positive results. So this time we’re checking out the top-of-the-line Model A, a radically styled 40-litre two-way floorstander that comes in a wide range of colours and finishes. The styling is certainly very original and striking. The thick and wide steel wrap forms a tall inverted-U, covering the sides and top, and is firmly bolted onto the outside of a wood-composite enclosure that’s wide enough to accommodate the relatively large 200mm paper-cone bass/mid driver."

"A reflex port is fitted into the base of the enclosure, firing downwards and held about five centimetres off the floor by some very well founded and purposeful spikes. The enclosure is roughly the same depth as it’s width, so the footprint is quite modest, but the hefty 28kg weight seems to confer good physical stability. As part of the time alignment, the two drivers are mounted on separate baffles, so the bass/mid driver fixing is nearer listeners than the 28mm soft dome tweeter. This also provides some mechanical and acoustic isolation between the drivers."

"The two separate grille cloths are available in a variety of colours. Connection is made via twin terminal pairs, allowing the bi-wiring or bi-amping."

"Sound quality. MonoPulse refers to a concept it calls ‘impulse synchronism’ as the key ingredient that distinguishes its loudspeakers from its rivals. And, as soon as the speakers were connected up, it was immediately obvious that they offer something very special in the way the leading edges of voices and musical instruments are defined. As a direct consequence, music is delivered with a dynamic vividness, integrity and sheer excitement."

Go to more Model A reviews »

Hi-Fi News - July 2005

Phase change.

Hi-Fi News"Your speaker's drive units may be connected out of phase. It isn’t faulty – it was designed that way. But, asks Keith Howard, is this really a good idea?"

"If you are familiar with the design of loudspeaker crossovers, you will know it is common practice to internally connect up drive units with opposite polarities. Average hi-fi users, with the familiar warning about connecting speakers to the amplifier with consistent phase (red erminal to red terminal, black to black) ringing in their ears, will find this odd."

"It turns out that the knee-jerk reaction to consider it strange may be the right one. Some loudspeaker designers have come to the conclusion that it is a bad habit the audio industry should break. Talking to a succession of speaker designers in recent months, they have mentioned a factor which isn’t often heard about – loudspeaker impulse response - and the impulse response of a typical multi-way loudspeaker is not a pretty sight."

"MonoPulse speakers have been designed with impulse response firmly at the top of the agenda."

"Allan Hendry [see the March issue review of the MonoPulse Model S] justifies his unusual choice of crossover filters on the basis that it allows the bass-mid unit and the tweeter to be connected in phase."

"If you put an impulse into a speaker with opposed driver polarities, then as one diaphragm moves forward, the other will move back – an intuitively undesirable situation, particularly given the established significance of leading-edge transients in music."

the ENGINEER - July 2005

Hi-fi entrepreneur Allan Hendry's loudspeakers garner high praise from music buffs .

"MonoPulse, a loudspeaker company that is attracting rave reviews from the critics."

"Is it a consortium of of German PhDs perhaps? In fact the answer is Allan Hendry, an engineer turned hi-fi entrepreneur. The name MonoPulse relates to the radar technology he was involved with."

"The specific technical issue to which Hendry turned his attention is the time domain accuracy of a speaker."

"They look as they are intended to function, style does not compromise function."

Hi-Fi News - May 2005

MonoPulse erratum.

Hi-Fi News"Regrettably, due to a production error, the final paragraph in Keith Howard's review of the MonoPulse Model S loudspeaker was omitted from the March issue. 'Its fundamental honesty of sound is its key attribute and opens the window on a musical performance in way that many slugged-sounding speakers – of which there are still too many – never can. This is what real high fidelity is all about, and it will deservedly win the Monopulse Model A many friends."

Go to more Model S reviews »

HI-FI CHOICE - April 2005.

MONOPULSE MODELS

Hi-Fi Choice"Independent loudspeaker specialist MonoPulse has upgraded its distinctive speaker range for 2005."

Founder Allan Hendry has beefed up the rolled-steel surround - a key feature of the cabinet's unusual steel and MDF design on the Model A"

Each custom-built pair comes in a choice of colours and finishes."

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Hi-Fi News - March 2005. MonoPulse Model S, by Keith Howard

With an unusual crossover design as well as distinctive looks, this loudspeaker aims to preserve musical 'attack' above all else.

Hi-Fi News"In a world of clones – which might be considered evidence of convergent evolution or lack of imagination, depending on your frame of mine – it is a pleasant change to encounter a loudspeaker that’s a little different, outside and in. The MonoPulse Model S, designed and made in the UK by Allan Hendry, is nothing if not distinctive, from the stretched cloth covering that defines its appearance, to the philosophy that underlies its creation."

"Hendry’s guiding design principle is the maintenance of leading-edge information – the ‘attack’ portion of musical notes that is known to be so vital to our perception of each musical instrument’s distinctive character."

"To achieve this, he deploys an unusual form of asymmetric crossover, quite unlike the Linkwitz-Riley (Butterworth-squared) symmetrical alignments so commonly used elsewhere. The low-pass roll-off of the bass-midrange unit – an aerogel-coned unit from Audax – is nominally first-order (6dB per octave), while the high-pass section feeding the tweeter (a soft-dome unit) is fourth-order. Moreover, it’s a fourth-order filter of an unusual type, which has been variously referred to a Papoulis, Fukada, Legendre, Papoulis-Fukada, etc. Whatever you choose to call it, its distinguishing feature is that it provides the most rapid roll-off possible consistent with a monotonic frequency response, that is, one without ripples."

"This combination of filter slopes has attractions aside from its favourable impulse behaviour. A first-order response on the bass-mid unit means the minimum of potentially nonlinear crossover components are required and allows the driver’s natural roll-off to contribute at least some of the filtering. A fourth-order slope for the tweeter protects it from low frequencies, improving its power handling."

"Buyers can choose from a variety of fabric colours for the cabinet covering. If you move house or redecorate then the covering can be changed to suit. Underneath the exterior is a conventional MDF box incorporating a downward-firing reflex port. To ensure sufficient space is maintained beneath the cabinet for this to operate correctly, tall spikes screw on to short lengths of studding. Nylon versions are available if the speaker is to be used on a hardwood floor. A split crossover, accessed by two pairs of upward-angled gold-plated binding posts, allows for bi-wiring. As supplied these are linked via gold-plated straps to allow use with a single speaker cable. Nominal impedance is 8 ohms, and rated sensitivity is 89dB."

"I favoured pointing speakers straight down the long axis of my room since this ensures a more even spectral match between the direct sound and first side-wall reflection, which results in a greater sense of scale both dynamically and spatially. Normally you wouldn’t be able to get away with this with a two-way speaker crossing over as high as 4kHz because listening off-axis would suppress the presence band too much, but as the 32 is a little over-endowed in this area I found it worked well. With different system balances, not to say different tastes in tonal balance, this arrangement won’t always be suitable but owners would do well to experiment with the angling of the Model Ss since this allows quite effective control over its voicing. I tend to prefer designs that are flat or even a little recessed through the presence band, soon-axis I found the 32 a little too forward-sounding. Angled as described, its sound became warmer and its imaging broader and more substantial – which happens to be the way I like it. Although the Model S sounds less obviously detailed when you do this, its inherent transparency still shines through."

"It seems to have an unusually ‘quiet’ cabinet for a floorstanding speaker in this price category. Despite the relatively large area of the cabinet’s panels there is little sense of it contributing unwanted output, the sound being free of tell-tale boxiness. This helps you appreciate the Model Ss even response down to what are quite low bass frequencies for its size. At the other end of the frequency range the decay spectra confirmed that the tweeter, despite its soft dome, is free of the diaphragm resonances that used to add a sibilant tizz to drivers of this type. As a result, the Model S's treble is clean and detailed. Set up as I’ve described the Model S gave a fine account of itself, at least as good as any speaker I’ve heard at this price. Its fundamental honesty of sound is its key attribute and opens the window on a musical performance in a way that many slugged-sounding speakers – of which there are still too many – never can. This is what real high fidelity is all about, and it will deservedly win the Monopulse Model S many friends. Keith Howard."

"Hi-Fi News verdict: This distinctive British-made two-way majors on a transparent, honest, musically involving sound. Tonal balance is a little mid-forward but this can be improved with careful set-up. Good bass extension."

Go to more Model S reviews »

Hi-Fi News - July 2004. MonoPulse Model A, by David Alcock

Fancy electrostatic sound from a sharp-looking conventional speaker? Meet the MonoPulse Model A.

Hi-Fi News"Could it be that this unconventional looking two-way floorstanding is every audiophiles dream?

Slim and unobtrusive, the Model A initially looks like a panel speaker, yet the aesthetics derive from designer Allan Hendry's belief that to work correctly speakers must not only be time-coherent but also phase-coherent, too."

"The Model A has two clear elements to its design. The 200mm mid/bass is mounted at the very top of its enclosure, bringing its centre point as close together as possible to that of the tweeter, while the tweeter itself is set back from the main baffle to time align the two drivers. Each 40 litre cabinet measures 1140 by 250 by 250mm (hwd), weighs 28kg and is constructed from a combination of 20mm and 26mm MDF with 6mm steel plate wrapped in an inverted 'U' around the side and over the top of the enclosure. This combination has been chosen to produce an inert cabinet for the drivers."

"The Model A offers 90db/W/M sensitivity (particularly suited for use with valves and class-A amps) and a power handling of up to 550 watts."

"These speakers have to be positioned very much as you would electrostatics, with the 42As being positioned in the location vacated by my reference SL-3 speakers. The Monopulse clearly tells you when you hit the right spot, the images locking into space."

"The bass was both very agile and richly textured, and the ability of the monopulse to capture the texture of a string vibrating or the body of an instrument resonating was far greater than I expected at the price. It brings the kind of resolving capability and imaging one would normally associate with small electrostatics like the Martin Logan Aerius i to a far wider audience."

"The ability of these speakers to capture subtle nuances and inflections in vocal performances is outstanding. True out-of-the-box imaging was apparent from the first notes heard, with the lateral stage extending well beyond the outer edges of the speakers and giving the illusion of imaging beyond the physical room boundaries. The lead guitars on the track 'Boxes' are located on the far left and right edges of the stage, and with the Model A these guitars were precisely located outside the room with the images portrayed solidly and with real presence."

"Image focus was also excellent, with a real feeling of air and space around the images. The depth of the image was good, too, though contained within the boundaries of the listening room. Yet once again in the delineation and separation of images in the depth perspective was far beyond what I expected at this price point. Moving to Dave Brubeck's Time Out [Classic Records CS 8192], the speaker showed excellent dynamic tracking, with the rapid run of saxophone notes midway through 'Blue Rondo A La Turk' being reproduced with outstanding clarity, each note existing within within its own space and without truncation of the initial transient or the decay of the note, with the variations in the power of each note played by Paul Desmond being clearly portrayed."

"At the other end of the spectrum Anastacia's 'Not That Kind' [Epic 497412 2] is a recording that is intolerant of over-emphasis in the high frequencies, a trick used by some designs to give the illusion of resolving ability – but this is clearly not a device used here. High frequencies were richly detailed and rendered with a level of textural detail, ensuring that cymbals and high hat were delivered in a convincing and realistic manner. Even triangles and tambourines on 'cowboys and kisses', instruments buried way down in the mix, are clearly discernable as individual instruments and are never allowed to dissolve into a high frequency hash as is so often heard on lower cost speaker designs. Once again this speaker showed its affinity for vocals, with even the most subtle inflection in Anastacia's voice being captured and portrayed with ease, while the raw power of her delivery was conveyed in an appropriately startling manner. There is no doubt in my mind that in his pursuit of phase accuracy in the overall design of a speaker, Allan Hendry has identified a key component of delivering realistic sound."

What's more, while it's suggested the Model A be used with valve amplification, it makes an excellent match for many solid state integrated amplifiers. This speaker proves itself to be highly articulate, boasts excellent resolving and imaging capability, and is highly transparent throughout the critical midrange and high frequency band. If these abilities are high on your list of priorities for your next pair of loudspeakers, then the Model A should be a mandatory inclusion on your shortlist. And, thanks to its lower cost and ease with which it can be driven, I feel that it brings the kind of resolving capability and imaging one would associate with small electrostatics like the Martin Logan Aerius i to far wider audience. From me, that is more than enough to elicit a firm recommendation.

"Technology. The 200 mm bass/midrange driver and 28mm tweeter used here are both conventional designs, but far from conventional is the use of a fourth order crossover on the tweeter with a Legrandre filter and a first order crossover on the bass. This arrangement is key in maintaining the phase relationship of the signal. Setting the tweeter in its own enclosure on top of the cabinets allows alignment of the tweeter and the mid/bass drivers' acoustic centers in the time domain, while the crossover is claimed to prevent any anomalies being introduced in the phase domain, allowing the musical waveform to leave the speaker intact in both phase and time domains. Few speakers achieve this, save for electrostatics panel types such as Quad and Martin Logan."

"David Alcock."

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HI-FI CHOICE - May 2004.

PULSATING SOUND - New Flagship MonoPulse Model A

Hi-Fi Choice"MonoPulse has introduced a new flagship speaker. The new MonoPulse Model A with a new bass driver said to give greater extension and control, and a claimed sensitivity of 90dB."

"The Model A uses a steel-enclosed construction bolted to a wood composite enclosure in choice of colours."

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HI-FI CHOICE - September 2003. By Paul Messenger.

MONOPULSE Model S. A radical look and sound from a newcomer with bright ideas.

Hi-Fi Choice"A brand new name on the scene, MonoPulse was founded by long-time hi-fi enthusiast Allan Hendry, who has experimented with speakers for decades, but until recently, earned his living in electronics, working on phased-array radar systems. It's experience that may not seem to have much relevance to speaker design, but it has made him particularly conscious of the phase relationship between bass/mid driver and tweeter through the crossover region. That's very much reflected in the way the network is designed and the drivers are spaced."

"No less interesting is the styling here, which is very original and also decidedly attractive to these eyes."

" A reflex port is fitted into the base of this enclosure, firing downward and held an appropriate distance off the floor by some very well founded and purposeful spikes – the footprint might be modest, but stability seems good here, helped by the 12kg total weight."

" Like the metalwork, the grille cloths are available in a variety of colours, while connection is made via twin terminal pairs, allowing for bi-wiring or bi-amping."

" There are many exaggerated claims for superior performance in this business. Happily, the MonoPulse fully lives up to its claim that it will supply superior stereo precision and focus. The sound is pretty well balanced overall, and delivers a coherence and timing that's positively electrifying."

"A vivid sound that gets you close to the music It's a vivid edge-of-seat experience, which somehow seems to 'direct-couple' the music to the brain much more effectively than most."

" Playing Christy Moore's Live At The Point, it was almost as though one had been transported to that famous Dublin venue."

"The exceptional image precision, alongside the fact that small head movements result in significant shifts in the perspectives, are very reminiscent of what one hears with wide-range electrostatic speakers – and a sure sign that this speaker does indeed have phase accuracy that's very rare indeed in a regular box speaker."

"This Model S is an exceptionally creative design, not just in its unusual appearance and methods of construction, but more especially in its vivid sound quality, which simply gets you closer to the music than most of the competition. HFC"

HI-FI WORLD - August 2003

PULSE POWER.

Hi-Fi World"MonoPulse is a new British loudspeaker company which wryly states that 'the answer to life, the universe and everything is a combination of precise detail and clean, undistorted bass power', which its new Model A loudspeaker delivers."

Hi-Fi News - July 2003

New brand steels limelight.

Hi-Fi News"New speaker manufacturer MonoPulse has launched a range of speakers."

"These solid floorstanders are made from MDF clad in 6mm-thick steel plate."

"Using two offset drive units and sophisticated crossovers, the MonoPulse units are designed to express transient sounds with great accuracy."

"Bi-wire terminals and adjustable M8 spikes come as standard."

HI-FI CHOICE - June 2003

FINGER ON THE PULSE - SPEAKERS FROM ALLAN HENDRY

Hi-Fi Choice"Specialist privateer speaker manufacturer Allan Hendry has announced details of his latest project - five loudspeakers called MonoPulse, available from a small number of dealers."

"MDF cabinets enclosed all round with steel plate giving a high mass and greater damping properties."