Acelec Model One loudspeaker Page 2

Because of their extraordinary focusing and structuring talents, both speakers—the Acelec and the TAD—shared a knack for making me pay attention to, and oftentimes enjoy, music I did not appreciate previously.

One such piece, Richard Strauss's Metamorphosen, TrV 290, performed by the recently formed (2018) Sinfonia Grange au Lac, conducted by Finnish conductor/composer Esa-Pekka Salonen (24/48 FLAC, Alpha Classics/Qobuz), drew me all the way in and held my attention all the way through. This never would have happened with a lesser speaker. With the Acelec Model Ones, the orchestra's swollen, cloudlike textures entered my room mixing lush tones of doom with quick, well-defined transients. No blur or crimping between instruments. No gray graininess. Only dense, tactile tones floating through a water-clear soundspace.

Composed in Germany in April 1945, the harmonics-rich melodies in Richard Strauss's Metamorphosen intertwine in a manner suggesting roused dead souls weaving through the ether. With the intense tone and textural mass of 10 violins, five violas, five cellos, and three double basses, this late Strauss appears to express something brighter and more universally spiritual than would be expected from a German artist at that time.

Despite the fact that I was raised in a German-speaking household and therefore feel obliged to embrace this music, I've struggled to enjoy recordings of Richard Strauss compositions. I associate their relentless use of massed strings with schmaltzy orchestral scores for cinematic melodramas. Since my youth, my artist's taste and audiophile ears have rejected that type of orchestral poetics. Maybe all I needed was the right speaker.

The Model One's uncanny resolution seemed to wash away the schmaltz. These speakers' extreme clarity forced me to notice, then actively enjoy, aggressively romantic music that I'd previously avoided. I've now played this Alpha Classics' Metamorphosen all the way through at least five times, and only now am I starting to grasp its structure. I'm enjoying my time trying to comprehend its moods and heroic spaciousness. That I could listen to any piece of music, let alone one I didn't previously like, with that level of attention and intention speaks volumes about the loudspeaker I'm describing.

With 300Bs
I was seduced by the Strauss recording while trying the Model Ones with Elekit's 8Wpc TU-8900 amplifier equipped with Psvane T-Series MK II 300Bs. Before that, the high-powered Parasound Halo A 21+ was digging everything out of every recording, playing perfect bass, and sounding just right. The Parasound seemed like the perfect amp for the Ones, but when I played the Strauss with the 300B Elekit, it excavated a measure of sweetness and sharp-focus tactility that wasn't there with the Parasound. The Elekit's relaxed elegance made Strauss's Metamorphosen more palatable. Who in audiophilia would have predicted that this serious-looking speaker would respond so well to the petite urgings of only 8W? Not me.

I was so surprised that I wrote to Cees Ruijtenberg and asked him why this was happening. "Is it the crossover?" I inquired.

Cees replied via email: "That is extraordinary, that the 300B does this so easily, but did you perhaps use the 4 ohm tap?" I did. "It's probably because, unlike other designers, I use impedance correction, so the speaker behaves more like a constant load." "Impedance correction" means that the crossover was designed to avoid dramatic peaks and dips; it will be interesting to see what JA's measurements show.

At modest, small-room listening levels (approximately 83dB at 2m on average, 94dB peak, C-weighted), the Elekit TU-8900 drove the Acelecs with nary a quibble, even on dynamic high-density programs.

With the Pass Labs XA25
The Acelec Model One's specifications recommend amplifiers with 25 to 100W—so how could I not try the Nelson Pass–designed Pass Laboratories XA25, which I consider the pinnacle of solid state transparency. The $5000 XA25 is rated at 25Wpc into 8 ohms and 50Wpc into 4 ohms, but John Atkinson measured 130Wpc into 4 ohms. I had high hopes for my most invisible amp meeting this conspicuously transparent speaker. Would there be a wedding?

This amp-speaker pairing is where "shimmer" entered the sonic picture. It always takes 24 hours of warm-up for the XA25 to start sounding right, but when I switched from the TU-8900 to the XA25, the soundspace instantly got wider and the string tones on that Alpha Classics' Metamorphosen began shimmering in a most delightful way. The XA25 added a surprising touch of luminosity to the Model One's purity.

Watching the Acelecs play the Strauss with such pleasurably detailed resolve, I thought I'd try a more difficult test. I selected my favorite bass-demo album, Bill Frisell with Dave Holland and Elvin Jones (16/44.1 FLAC ECM/Qobuz), and was surprised by the amount of 50Hz–100Hz energy these 6" drivers were putting into my room. With my Falcon LS3/5As, the bottom octaves of this album play muddy and IM-distorted. The GoldenEar BRX reach a half-octave lower but struggle to achieve undistorted clarity in the 50Hz region. The similar-sized but more expensive Acelecs delivered Dave Holland's bass with more clearly structured resolution than either of those other standmounts—but only after I inserted the foam port plugs I found in the box with the aluminum cones.

In my room, on Bill Frisell with Dave Holland and Elvin Jones, I heard a fluffy, annoying, narrow-band "boom" centered around 50Hz. The gray foam plugs made this 50Hz puff disappear, permitting the Acelecs to play this recording without the low-frequency muddle I usually find distracting. When the Frisell-Holland finished, I took the plugs out, because I liked all my other music better without them. Overall, the Acelec's bass was tighter, cleaner, went lower, and was more musically satisfying than any of the other speakers I have piled in the hall (footnote 1). Compared to my Gold Badge Falcons, the Model Ones (with and without the port plugs) made bass notes feel louder, lower in tone, more sharply focused, and more physically powerful. The Acelecs reminded me how little energy the LS3/5a delivers below 80Hz and how, undoubtedly, the Model One's extra low-frequency energy helped me connect to Strauss's Metamorphosen.

Raving about Acelec's transparency is like saying water is wet; the first sentence on Audio Art Cable's website extols this virtue: "The Model One is possibly the most transparent conventional loud speaker available today." I can't dispute that. After I set them up, it took me less than a minute to realize: These speakers are playing whatever signal they're fed, with vanishing levels of coloration.

But many top-end speakers deliver vanishing levels of coloration.

What these small, easy-to-drive monitors do that the majority of top-level speakers don't do is play all genres of music with equal facility and a goodly amount of fun. Acelec's Model Ones play small (power- and energy-wise) but image big: Their clear, expansive soundstage was mesmerizing; it kept my focus on whatever music it was presenting.

Similarly, the Model Ones kick the rhythms forward effortlessly. That's what it takes to make all types of music enjoyable. The Acelecs liked Lester Young as much as Lester Flatt, and their excellent bass made a god of Leslie Claypool. The Ones soared with sopranos and played pianos as well as any speaker could with a woofer not much bigger than a CD. Even with that small woofer, they played giant classical orchestras with zero strain and flawless resolve. What more could anyone ask from two small boxes in a small room?

Most of today's speakers sound good. I haven't noticed any really bad ones. Unfortunately, most of today's speakers sound like each other. Only a rare few jump out of the deck and strut their exceptional-ness like Acelec's Model Ones.

The only speaker I know that can match this speaker for its precision and charm is TAD's CE1TX, which I described in my previous review (footnote 1). But while the TAD delivered a fuller, more complete harmonic palette, it was less radically transparent than the Acelec.

If you enjoy clean, high-rez monitor sound as much as I do, but you also need a strong rhythm-keeper with some sweet and juicy tone—especially if you want a rhythm-keeper that can play with low-power triodes—Acelec's reasonably priced Model One could be the speaker you've been searching for. Highly recommended

Footnote 1: The TAD CE1TXes are not piled in my hall.

Acelec/Sonnet Digital Audio BV
Daviottenweg 9-11
5222 BH's-Hertogenbosch
The Netherlands

tenorman's picture


georgehifi's picture

Nice review, but!
$6.5K usd for an 11" two way!! You guys are tripping? drunk? or bombed? Or is everyone in the US a multi millionaire?

Cheers George

JRT's picture

A loudspeaker with MSRP approximately 5x multiple of the low volume retail pricing of the BOM components in total usually represents fair pricing. This loudspeaker is priced well below that, just considering woofer and tweeter, not including the crossover and other misc components, and without any consideration of the nontrivial enclosure. And it does seem to perform well.

The drivers are not cheap. Madisound's mailorder retail pricing for ScanSpeak Illuminator 15WU/4741T-00 is $381/each, and for Mundorf AMT21CM2.1-C (air motion tweeter) is $534/each. While I wouldn't know if this loudspeaker uses those exact off the shelf drivers or some OEM variants better optimized for the specific application, these drivers are sufficiently representative for use in coarse estimates.

$381 + $534 = $915 for the drivers in one of these loudspeakers, x2 = $1830/pair, x5 = $10980, nearly $11k. The MSRP is only $6.5k/pair.

Whether or not one might consider it to be well engineered is another very different conversation that must include the opportunity costs of what else could be achieved within the same budget.

georgehifi's picture

From Mundorf and ScanSpeak, in lots of probably 100 or even more, and the costs would be around 1/8th of those retail sellers prices, $228 for drivers for the stereo pair, plus box cost etc.

Cheers George

JRT's picture

Of course the manufacturer is not buying drivers at retail prices. That coarse approximation also does not include all of the other costs.

It is just a useful heuristic coarse approximation which uses a 5x BOM to MSRP with low volume retail pricing on the BOM components (which would include not just the drivers, but also the crossover, enclosure, lining and stuffing, wire, binding posts, screws, etc., which I didn't bother to include all of that because the prices of drivers alone clearly indicate a low MSRP relative to costs). It is just a sanity check on pricing of loudspeakers of moderate production volume.

Also... That 5x multiple does not apply to the very low volume high end statement products trotted around to the audio shows for marketing purposes, where high pricing adds to the wow, and the intent is to attact customers to other less expensive product. Those can exceed 20x BOM to MSRP.

My source on that was Siegfried Linkwitz, more than 2 decades ago in some discussions on the old Mad-board, either while or shortly after his involvement with Audio Artistry. SL's Audio Artistry Beethoven design was Stereophile's loudspeaker of the year in 1997. I have included a link to the review below. His heuristic coarse approximation still seems to hold up well enough to remain useful.

Dennis Murphy's picture

This appears to me a very well engineered speaker with expensive drivers and what is probably an extremely expensive cabinet. However, the woofer is not from the Scan Speak Illuminator series. It's from the older and less expensive Revelator models--the 15W/8530K-00 It retails for $221. To the very best of my knowledge, there are no neo magnets in any of the Revelator woofers.

Long-time listener's picture

One other thing I don't quite understand is why manufacturers now want to make all their bookshelf speakers SO small, when a slightly larger cabinet and woofer could bring better bass extension. Maybe they assume everyone will use a subwoofer if they want bass extension. Not me. One other example is Revel, who downsized their famous old M20, again limiting bass extension. Anyway, I just don't want to have to pay $6,500 and then have to get a subwoofer on top of that.

Archimago's picture

Not everyone. But apparently all Stereophile readers are.

Indeed. A wee bit pricy... At least the measurements look alright.

teched58's picture

The funniest thing re the closing line of the review: "Acelec's reasonably priced Model One could be the speaker you've been searching for..." isn't just that it was probably added in during the edit.

It's the no one who makes their living at Stereophile could "afford" this speaker, if we're talking about the money they make from this site. (Not talking about rich relatives or remuneration from other careers, e.g., the eminent, retired professor in Manhattan who is a contributor.)

So TO WHOM IS THIS tiny little but very expensive speaker AFFORDABLE?

It's also very funny that Stereophile thinks that the little editing tic of putting "affordable" into every review makes it so.

In fairness to the current regime, I think it was Mikey who started this practice years ago. Perhaps to convince himself that he could "afford" the $100,000+ turntable for which he took out a bank loan.

JRT's picture

"Not even the people at Stereophile could afford this" - teched58

If the reviewer buys the review sample, after the review, then it is no longer a new version in an unopened box. Rather the condition is that of a demo unit, because of the review.

I would hope that a reviewer could acquire it at a discounted accomodation price in the vicinity of dealer cost or maybe further down near the distributor's/importer's cost, if the condition is simply broken-in from use in the review, but otherwise as-new in all functions and cosmetics, with original box, packaging materials, paperwork, full warranty, etc. If it has suffered some minor inadvertent cosmetic damage, then it should be further discounted accordingly.

And whomever is paying the freight on the review sample saves the cost of the return shipping, an argument which the reviewer might use in further improving the discounted transaction price.

And if delivered from the distributor or manufacturer from out of state inventory, there might not be any sales tax in the transaction price. Herb lives in Brooklyn, NY, which has a sales tax rate of 8.88%.

Anton's picture

If a seller/whomever offers in home demonstration of gear, then shouldn't I get 'used pricing' on it after trying it in my home? And, if I slightly damage it, I would insist on an even greater discount.

Count me in!

I'm gonna use this idea. After I take a car for a test drive, it is no longer new, and I should get used car pricing.

Kal Rubinson's picture

Worked for me. I did a test drive in a car, came back 2 weeks later for another and negotiated a lower price based on its use/mileage.

Anton's picture

I could 'save up' and get one. Maybe if they had said "reasonable accessible?"

I'd actually love to compare this to a vintage Infinity Intermezzo 2.6....aluminum enclosure, very easy to drive, not overtly large...

Class A sound, in it's day.

Even setting this new speaker next to a Celestion SL600Si (even though it is 30+ years on) might be fun.

Speakers this size are perfect for shoot outs. Our club has done some and they have been extremely eye opening.

Ortofan's picture

... speakers of essentially the same size or form-factor, how about a comparison with other speakers that are similarly priced?

What might be the outcome of a shoot-out between the Acelec Model One and the KEF R11 Meta, the Klipsch Cornwall IV and the Wharfedale Dovedale?

bhkat's picture

It would be interesting to see this manufacturer make a floor standing speaker that sells for around double. This speaker's FR measures better than the $100,000 speaker reviewed recently.

Long-time listener's picture

I appreciate Herb Reichert's reviews, as I appreciate all Stereophile reviews. Except when they say things that have no meaning: "a slight, eerie density hovering near the musical program..." NEAR the musical program? Where would that be? And "density" ... of what? If there's a problem with this speaker, language like this isn't communicating to me what it is.

johnnythunder1's picture

It's good writing. I know exactly what he means and I don't want to read a dumbed down version of HR's descriptive abilities. I think he perfectly described a VERY subtle type of coloration based on the construction and materials of that speaker. And "hovering near the musical program" simply means that this subtle coloration is affecting the music coming out of the speaker.
Or at least that's what it meant to me.

johnnythunder1's picture

Like a Monet painting as opposed to a detailed photograph. Herb doesn't write "white papers" thankfully. He's trying to express a "feeling."

Herb Reichert's picture

infuse the recorded program like cream in your coffee.

In my reviews, I do my best to describe what I notice in terms mastering engineers would understand.

When I say “faint” and “near” I mean the Acelec's box coloration is barely noticeable, and that if you listen carefully and you do happen to notice it, it is sitting off separate from the sounds of the recording. From a listening standpoint this is ideal.

I hope that clarifies "near."

As for “density” I always mean that as a measure of the amount of information being transmitted by a system combined with the apparent intensity of sound energy coming out of the speakers.

If you ever experience 30ips tape recordings played through big Genelec Studio Monitors you’ll know exactly what I mean.

I hope that helps because I want to be as specific and choose my words as carefully as I can.


jimtavegia's picture

I have an album, not the only one, where there were (many) 12 engineers involved with just the recording of the album's tracks. They are all over the place sonically. I don't understand the reason an artist would do such a thing and every track sound different with varying levels of compression, EQ, and limiting. Not a good album to use as a speaker test, sadly. I am a fan of this artist, but may be most of his fans could care less about recorded quality?

I think of the sonic variances of Gould's 1955 and 1981 Bach pieces that had tremendous recording differences and pianos. I have both as many do and find the '55 recording thin and not very realistic. I think both were done to tape.

Do you define as your standard the 30 ips recordings as heard through the Genelec's? That certainly would give you a one-up on those of us who have not heard that.

I am going out this week to start the audition process for some new bookshelf speakers and my first one is going to be the small Magico's. There is a dealer not too far and I will take some music I know and begin the process of hearing what is near the best in that category. It would take a lot to "wow me" to drop this kind of money on speakers, but I am going to start there and see where it takes me.

As for the recordings, since we are not there in the room where the recording is made we have no idea if what the engineer did or the mic choices he made captured accurately what is going on in that room. I am sure something is always lost. Just a part of the process where choice determine the outcome.

I appreciate your thoughts on this. It is complicated is an understatement.

Herb Reichert's picture

I've only heard 30ips a few times and then only briefly.

I was using the 30ips/Big Genelec comment as an illustration of what information density and sonic intensity sound like together.


Glotz's picture

AXPONA had a very nice demo with Garth Leerer and ticked all of the boxes for a small mini, for me. Stunning and satisfying.

I would love to have Herb review them in context of the other monitor speakers he's been reviewing of late.

RH's picture


"As for “density” I always mean that as a measure of the amount of information being transmitted by a system combined with the apparent intensity of sound energy coming out of the speakers. "


I had interpreted your general use of the term "density" differently.

I thought you used the term the way I do: to describe when a speaker produces more of the sensation of a corporeal sound, especially in the sense that it's sonic images were "solid" and "dense," closer to the sensation you could reach out and touch the object, rather than having a ghostly, see-through, "wave your hands through it" quality.

The Devore O series speakers, for instance, for me produce more density, more "flesh and blood" presence, than I hear from your average skinny floor standing speakers, which transmit plenty of "sonic information" but produce a more spectral-like soundscape.

Herb Reichert's picture

"I thought you used the term the way I do: to describe when a speaker produces more of the sensation of a corporeal sound, especially in the sense that it's sonic images were "solid" and "dense," closer to the sensation you could reach out and touch the object, rather than having a ghostly, see-through, "wave your hands through it" quality."

But lately, I am noticing that the illusion of corporality can also display a force or intensity factor.

Corporality is surely the result of more low-level information getting through without being sucked

out during DA conversion or in a complex crossover.

Or maybe I've played "White Rabbit" too many times?


RH's picture

I hoped I hadn't been misreading you all this time! :-)

Btw, I wonder if your experience agrees with the following...

There seem to be different aspects of "density" and "body" portrayed in different systems.

For me, a sense of sonic density and palpability is a characteristics I'm always seeking. I ultimately prefer tube amps, and have been using CJ Premier 12 tube monos for many years. But I often grab different SS amps to try. My observations are that both the tube amps and the solid state amps provide density, but in a different way.

The solid state amp produces a sense of solidity and impact with leading edges of sound, and especially hard edged sounds. So for instance a hard edged "industrial" synth bass line in an old Depeche Mode track will appear as a very tightly controlled, narrowly delineated, solid column in between the speakers, with leading-edge force. I liken the solid state presentation to the type of solidity one hears when striking a solid object with a hammer. Very convincing in that sense.

Whereas the tube amp will slightly soften the edges and fill out the sound, but "round out" the sense of body, vs the "skinnier, more malnourished" version of the solid state presentation. Trading some hard edged convincingness and percussive power, for a more convincing, expanded, richer sense of body. More like punching a big heavy bag, vs a hammer hitting a narrower solid object.

Does that "resonate" with you? :-)


I own Joseph Audio Perspective 2 graphene speakers and have owned Harbeth Super HL5+ speakers (the Harbeth line being one of my favorites). I concur with your Joseph Pulsar review, where you described the Harbeth as having more corporeality, meat on the bones, and textural presence, vs the more detailed, razor imaging and timbral nuance of the Joseph speakers.

I was attracted to Devore O series speakers for similar reasons. But I was still besotted with the incredible grain-free timbral beauty of the Joseph speakers (and their juicy, fun bass response).

FWIW: I have found that the CJ tube amps flesh out the sound of the Joseph speakers somewhat, and I've discovered that adding a curved diffusor behind and between the speakers has a fairly startling effect of bringing focus and density to the sonic images! So I'm enjoying the incredible detail and smoothness of the JA speakers, their enormous soundstage and precise imaging, but the instruments that occur around the speakers have a very convincing texture, and reach-out-and-touch it palpability. So far, close to the best of both worlds! (Though the Harbeth still pull ahead in the sheer human quality of vocals).


RH's picture

One reply per customer, I guess :-)

Ortofan's picture

So, how does HR prefer his "coffee" - with or without "cream"?

Would you choose this Acelec speaker over the Harbeth Monitor 30.2 XD?

Long-time listener's picture

I appreciate that.

I realize it takes a few more words, but "a barely noticeable box coloration, which in any case remains separate from the program material" would have been far more understandable to me than what you originally wrote.

But again, thanks for your reviews and for Stereophile as a whole, which I've been reading for decades.

Long-time listener's picture

Are they the primary target audience for this magazine?

jimtavegia's picture

This must be one of the least resonant speaker cabinets that JA1 has ever measured. I would guess that this IS a desirable thing in speaker cabinet design?

It would be the opposite of most string instruments where there must be wide range of resonances inside a violin, viola, or cello where there are posts that can me moved around to obtain the desired sound the instrument owner wants and they do move from playing, vibration, and humidity over time.

As for the price, I am over the higher prices as I get it as the builder does get to set that based on his costs and work. It is less than the bookshelf Magico model and that would be a good comparison in a side by side test.

It is clear that this is much different than the engineering of the newest versions of the BBC monitors of today. This is where the potential customers will have to audition and decide for themselves. Most of those customer can afford either one. The improved clarity of the vocals is not to be missed or ignored.

A good review and testing.

georgehifi's picture

"This must be one of the least resonant speaker cabinets that JA1 has ever measured."

So is a "Besser" building block
And both around the same size.

Cheers George

jimtavegia's picture

You could have separate chambers for the tweeter and the woofer.

Glotz's picture

Been a good comparison in the resonance discussion / comparison sections of the review?

I think transparency is simultaneously obvious and obscure when speakers are compared, but perhaps the lack of a cabinet could have drawn a useful comparison.

But perhaps not, in the realm of planar vs dynamic definitions of transparency to source. I do believe they are a moving target.

jgossman's picture

At some point we have to just roll our eyes. I have been sort of out of it since getting married and having a kid, but I don't want to hear a review of these against another 6k tiny speaker. I want to hear a review (honest to goodness review) of this against a Focal Aria 906, a Kanta at a still pricy for most people 3k+, and then a 6k floorstanding. The truth is, as I read the review all I could think is pull back the treble, then is there still all that "detail". I've heard a pair of Spendor BC-1's and I own a pair of vintage BW Matrix (before those awful kevlar cones). I know what REAL midrange detail sounds like. I'm guessing we aren't talking about the same thing with these modern tiny little monitors. I'm sure they sound fine. At some point we need to say "Really? I mean, really?".

MBMax's picture

Herb, you made no mention of comparison with the beloved Falcon LS3/5a's. Yes, half the price, but similar form factor and application methinks.

I just purchased a pair of Falcon Gold Badges to replace my beautiful pair of DeVore O/93's that I just couldn't get to work in my small space (HUGE 40-80hz resonance that I could not dial out). My placement options are very limited and the O/93 rear ports fed the nightmare bass hump, even when stuffed.

The Falcons have solved that issue (even on the rare occasion when I turn on my REL sub) and they are glorious. Every glowing word written is true in my estimation and the DeVores will have to find a new home.

That said, I wish I had heard of these before buying the Falcons, though the rear port and the 2x price probably would have killed the idea. Oh, and by the way, my 15W Shindo Montille drives the Falcons just fine.

Just for kicks and grins, how do the two speakers compare?

bilguana's picture

Please review the new ELAC Vela 404s.