Stereo MonoPulse

NOTE: My native language is Norwegian, so my English may be a bit sloppy here and there. Hope it’s possible to understand, but if not, give me a hint, and we’ll sort it out.

If there ever was a thing like a garage product, MonoPulse is the prototype. Made in a garage for real, but plays like it was made in high tech production facility. Join me listening to Monopulse A!

MonoPulse is Allan Hendry, Allan Hendry is MonoPulse. Allan Hendry owns a garage with a Jaguar in it, and he makes loudspeakers the only way it should be done in his garage. Or, let’s accept that some other speaker builders have different views on how to build speakers, but Allan Hendry, Audio Note, Blumenhofer, Kudos, Doxa, myself and a few others have rather similar thoughts on the subject.

The tested speakers visible inside the red circle…. Nude picture!

So, “the only way” of building speakers is:

• Two way

• Phase correct

• Simple (or no) first order crossover

• Top quality speaker units

Well, there you have it. Lately I have been listening to quite a few of the kind, and, surprise, I use exactly that type of speakers myself in my set-up. In my case it’s a Doxa 8.2 Signature, a way more costly design than the MonoPulse, but, as usual, the price difference is larger than the sound difference.

The MonoPulse Model A is, as most garage products, rather simple in design and finish; “form follows function”, smart and cost efficient it is, non obtrusive in a normally furnished home. Discrete is the word; rather slim appearance, width dictated by the 8 inch mid/bass, while the treble unit lives in it’s own little flat placed on the roof, and, this design detail is the distinguishing feature of the MonoPulse A, no doubt. Also, for the more creative between us audiophiles, you have no less than 10 different cloth colors to choose between,

On the rear we find the speaker connectors plus a very handy handle, you easily lift the speakers with this smart little design feature. The connectors can be ordered to customers specifications, the test object had a single wire, high quality set of connectors. Above them, you’ll find a couple of connectors for Brits; heavy furniture and thick carpets steal treble, put a jumper between the two, and get a couple of dB extra up in the highs. For the hard an cold Scandinavian homes, let the jumper rest in the box…

Under the speaker, blowing its rage down towards the floor, we find the exhaust pipe with its generous opening. That’s the bass port, of course; this is a bass reflex design, if you were in doubt. Also, we find four small supports down there, rather fiddly to put them in position and install the spikes, but hey, I said this was a garage product, right? Now, there’s a payback for that, too, hang on, and I’ll get there.

I have connected this easy-to-drive-design to 4 different amplifiers, all the way from 120 Watts class D, down to a ca. 15 Watts class A single ended valve amplifier, none of them showing even a hint of stress whatever music I threw on them. MonoPulse A will, with its 8 Ohm nominal / 7 Ohms minimum impedance, accept up to 300 Watts continuous power, while 18 Watts amps are considered minimum. Let me oppose to the latter; using the Audio Note P2 SE Signature shows with all possible clarity that controlling this 91 dB/1W/1m is a simple task indeed, as a matter of fact, this was a completely astonishing and powerful match.

The overall sound from the MonoPulse A is leaning towards the warm and cuddly, but not overly so. You’ll find the focal point somewhere in the lower midrange, still with nuances and natural timbres intact. It’s all about being natural and present also at lower volumes, in my opinion the tuning here is very clever and enjoyable, whatever volume you choose. And they can go loud, too, no need to fear limitations, even if having a party, every now and then. I mean, these beasts will tolerate short peaks up to 1500 Watts!

Generally I find them very relaxed, elegant, open and playful. To put it another way; just the way simple and good two-way designs shall sound! The best with all this? That MonoPulse achieves these results without costing an arm and a leg. In this price bracket, this is totally unique, and here’s the mentioned payback I was talking about. Some might react to my use of the slightly irreverently expression “garage product”, but here’s the answer for you. The likes of Allan Hendry are able to make products sounding like a million for just a dime, that’s the good thing about owning a garage with an old Jaguar in it!

I have, as mentioned, used a variety of amplifiers; the results I got was not necessarily as expected, though, but are they ever? To cut the story very short: the valve amp was the best, but I suggest a rather controlling version of the type. Like a very good parallel 300B interstage, if you are rich. If you can’t afford that curly and expensive way to the soul of music, use the short-cut; Rega, Heed, Naim, etc…

I got approximately what I expected from the fantastic Spec amplifier, but the very interesting thing I discovered, is that even a small Rega Brio had that little “something” about it, that made the music just that little tad more exiting. No, it wasn’t better than the 15 times more expensive Spec, but it was more enjoyable! It’s about tuning, of course, and matching. To me, NOS valves and/or 300B make these speakers literally fly, but tight and quick “PRAT” amplifiers comes close, very close.

The MonoPulse’s were easy to awaken; very often I have to use many hours of rather hard load to make the speakers relax and present their best sides, this pair was a breeze. I was, however, negatively surprised while fist connecting them; sleepy and grey would be a rather accurate description of what I heard. But, as mentioned, they loosened up quite quickly; a full bodied character came floating within the first 10 – 20 hours, after that, differences were rather limited. After thoroughly running them in a couple of weeks, it was time to hear if Mr. Hendry was right in his rather aggressive data; smallish speakers, easy load, efficient plus deep bass; does that add up in a real world? First, the 91 dB/1W/1m seems absolutely right. Not as efficient as the Doxa’s or the bigger Klipsch’es, but they still play more than loud enough with limited power at hand. Frequency sweep showed indeed useable output all the way down to 20, but something needs to be said about the lower parts of the register. The frequency curve is rather flat and controlled down to 35, where actually a port noise starts to appear, even clearer at 30 and 25 Hz. Then we face a rapid roll-off towards 20. For this size speakers, this is very good, indeed. I am, however, mildly critical to the port sound, although it is more difficult to hear it when large music works are presented, than when you listen to a pure low frequency sinus tone.

So lets go on to the music examples. Mostly I refer to the amplifiers making the best results in each case; often being the Audio Note P2 SE Signature, but in some cases also one of the others; a Rega Brio integrated, A Micromega class D 120 Watt power amp, and last, but not least, a Japanese 60 Watt powerhouse in shape of Spec RSA M3EX. In general the MonoPulse Model A is a very entertaining speaker, it makes huge soundscapes, it has a very good clarity of speech; meaning that it possess the kind of precision distinguishing phase correct speakers. Tuned slightly dark, treble unit not as good as the very best of the kind, same can be said about the bass. In some set-ups you might feel that the filters are not steep enough; creating a slightly overly focus in the area around crossover. But again, give them the right signal and amp, and you’ll have no issues, whatsoever. And, let me be clear on this, when I rise these minor issues, I compare this after all reasonably priced speaker, with anything money can buy.

So, let’s listen to Candy Dulfer, then, and her playful “N.J. Turnpike” about a highway in New Jersey, no less. The MonoPulse A presents this very involving, expressive, dynamic, with beautiful balance. The Rega and the AN wins this round hands down; steel glove control is not always as cool as you might think, so the most controlling amps are shamed by the fun and life presented from the small guys. Further, the saxophone gets that extra body and soul through the valves, the MonoPulses happily serves the meal steamy hot and spicy. I just love it!

So, to a completely different challenge. “Shake my tree” with Coverdale / Page is a complete disaster of a recording; I have no idea how they managed to make something so terrible, but they obviously did. This does not really sound good on anything, but it is very interesting to hear how different equipment solves the challenges presented to them. Early digital equipment (cd-players) are often struggling the most, but these problems are normally not present on newer gear. I have used this test for many years, mostly because it reveals so clearly what works, and what doesn’t. I have heard extremely costly, detailed and wonderful high end speakers completely demolishing this track, making it screech and whine, totally useless for enjoyment. And, I have heard simple designs presenting the music, instead of the recording, to my ears that is the whole idea, as a matter of fact. The MonoPulse takes this disaster as an English gentleman. It is smoother than most, muddy as hell, but still enjoyable. More or less entertaining depending on the amplifier in use, before the magic Audio Note touch settles this once and for all, bringing this terrible recording alive, incomprehensible how this happens. One might be able to like this crap! Have I ever heard speakers presenting this song better? I doubt it. The slightly warm balance of the MonoPulse in combination with the silky smooth treble, makes this more than tolerable, I am impressed.

Now to the total opposite, ’cause the Stockfisch recording of Chris Jones, “No Sanctuary here”, sounds good on absolutely all equipment I’ve tried it on. Disputable whether this recording is just an overly warm and soft “impresser”, but whatever you think of it, there are a few things you can find out by playing that, as well. One of the pitfalls speakers tend to fall into, is sounding too fat and lacking nuances in the deep notes, but the MonoPulse does not go there. They deliver deep and mighty, with beautiful vocals, this is spot on. The hint of extra weight in the deepest notes is audible, but actually I find that just giving this recording the small but important step ahead. Again, I find the match with the Rega puzzling; it just plays too good!

Now, over to music for adults, in shape of “Pesante”, Bela Bartok. A complex, rather difficult recording, lots of things going on, speakers must deal with several challenges. Here vi get beautiful timbre, open and airy, although violins may sound a little over the top, here and there. No need for the extra top energy jumper, that’s for sure. Each individual instrument has its own place, all in all I find the total result seriously good. Also, results underlines the fact that MonoPulse A represents an easy load on the amplification, again none of the amps had any issues to speak of. Here the quality of the signal was obvious and noticeable; you need more than just a good balance to make recordings like this really shine.

Still in the adult world, we calm down, listening to Scarlatti’s “Finale”, with Maria Kristina Kiehr behind the microphone. This Harmonia Mundi recording is a tad difficult on the voice, demanding elegance and quality from the source and amplifier. Again the MonoPulse takes this straight, but, as mentioned a couple of times, the top is slightly towards bright here and there. It balances just on the right side, though, making this an emotional and insightful experience.

Lots of musical examples were tried, I’ll mention two that really showed the qualities of this speaker, beginning with Hans Zimmer’s “ dark knight” from the Batman movies. It comes across deep, mighty and threatening. IT was obvious that the better amp we gave the speakers, the more mighty, insightful and gigantic the result was. The MonoPulse speakers may look small, but they sound anything but small, when filling the room with the huge waves of Batman!

Then I want to talk about Molly Johnson and her interpretation of Billie Holiday’s intense song “Don’t explain”. Especially with the Audio Note amp, this became a raw demonstration of emotional power, like Molly Johnson graces us with her presence, her emotions, her ability to deliver the lyrics with unbeatable conviction. To be able to deliver wit such intensity, the speakers must have the aforementioned clarity, a clarity I connect with phase correct behaviour, simple, high quality crossovers and high class speaker units. MonoPulse hits on all those targets, that’s not something you normally find in this price bracket, if at all.

So where does this put the MonoPulse A compared to the rest of the best? Very high. Ok, so the finish can be discussed. The port noise too. Apart from that, these are splendid performers, with ability to make music an emotional tour de force, with details, rhythm and enjoyment. There are competitors, but hard facts are that you wont find them for the price tag we’re looking at here. They shine with typical British amplifiers, and blossom with good valve gear.

The MonoPulse Model A is, to put it short, a garage product to die for!

Monopulse Model A, floorstanding speakers, £1,795 UK, EU 2,295.

For prices outside EU (as Norway), ask at info@monopulse.co.uk