Is the Accuton driver that good?

It seems a lot of new speakers are using the Accuton or similar ceramic drivers (and I notice the diamond variant for tweeters). I've heard them (mainly in Kharmas), but not others. Evolution, Salk, Avalon, and like I said Kharma use them.
Do they have any particular coloration or quality that is making them gain popularity? In the Kharmas, it was pace and timing and a natural sound without overhang, but it was different than regular (non-metallic) cones & domes, which, fwiw, are less detailed but maybe more relaxing.
It's like for me with the Kharmas "this sounds great and real and not bright or hard either" but somehow it is not as relaxing as the Aerials or Von Schweikerts or Quad dynamics(or even Apogees) I have lived with). I can't put my finger on it.

I'm not sure if it was just the Kharmas or the ceramics in general, but I wanted to raise the question.
Yes, I have used them in raw speaker designs and they are that good in my opinion.
It's the lack of coloration that makes them so good.
They are an extreme - lightweight and extremely rigid. Unfortunately, this means they are not that good overall. The approach to building a driver is a balance of many conflicting properties. For sure they are extremely lightweight, so ceramic drivers absolutely excel at linearity (pistonic behavior) but the price you pay is in resonance from ringing. This tends to create what I call a splashy sound compared to well designed damped drivers (pulp/paper/doped/fabric/polypropylene etc.)

Those little dots you see on the accutons are there for a reason - to try and compensate for the overly strong ringing problem. Speaker manufactures will also use "notch" filter with lightweight highly rigid cones to help compensate.

Of course, all designs are a compromise but my opinion is that it is best not to go for an extreme in the diaphragm but to choose a material to try to balance conflicting objectives. A design that requires heavy compensation for unwanted properties is not good design to begin with.

Just two cents... I understand those who will say "oh but it measures so well" on a frequency response plot...
I have Selah Tempestas w/ the 2" Accuton dome midrange. In my opinion, it is the most natural, uncolored and detailed midrange I've heard in 42 years in the hobby. Just beautifully clear and natural. It "rings" at 19 khz., and in my speakers that has been very effectively neutralized. I can't speak for the larger mids or woofers. I've heard a 1" tweeter that is very detailed, but perhaps a touch peaky in the speakers heard. As with any driver, the implementation is key, but the drivers themselves have many wonderful qualities.
Yep Shadorne, splashy is exactly the word for it. Not hard, bright, etched, just like a vague reminder of Niagara Falls.
It actually does sound like there is more realism. In regular drivers, something is missing and thus less natural, but maybe I can't handle the truth.
Shadorne, a competent designer shouldn't have a problem eliminating audible ringing from Accuton drivers. They're much easier to work with than your typical aluminum or magnesium drivers. Choosing the correct slopes, appropriate crossover frequency, and if necessary adding a notch isn't rocket science.

They are indeed easy to work with but that was not my main criticism of the design. An approach that depends on the Correction of audible artifacts is simply not a great starting point for a design.
Well, Shadorne may be right that the Accuton takes things too far, but it seems to me the counterargument is: there is a tradeoff in any technology used to reproduce music. Belt drive accelerates like a boatload of pig iron. Ribbon tweeters are hard to match to dynamic woofers. So forth.

I happened to like the Accuton-equipped JAS Audio speakers I heard in Montreal a few years ago. They just sounded a lot cleaner than I thought my own speakers were. OTOH the crossover, although it looked very well-made, also looked extremely complex.
I've owned speakers with Accuton drivers and have a friend who has a speaker with them and the diamond tweeter. I believe the thing that makes them so appealing AT FIRST, is because of their low mass, they are very quick which makes them very nice during the "10 minute demo" as I call it. This impresses many people giving them the impression they are accurate. I like a more organic and natural sound and, IN MY OPINION, the ceramic drivers are far from organic and natural. If I'm going to listen to ceramic drivers, I would put tubes on them. Personally, I'd stay away from solid state. Just my opinion. YMMV.
I am using tubes and Accuton drivers with great success for almost two years. These drivers pass on what is being fed to it, neither adding or subtracting anything. It is a pairing I do not see myself parting with. The tubes make these drivers the most natural speaker I have yet to here.
If one has a chance to experience a good 300b SET mated to a Accuton driven speaker, I'm sure it will not be soon forgotton.

Hi Montejay,
I `d love to directly compare an Accuton driver speaker and a PHY-HP 12" driver(considered supremely natural and organic with paper cone) with your Frankenstein amp. That would very interesting.
The Vandersteen 5A Carbon and the Model Seven use carbon fiber/balsa cones. Perfect Piston and no ringing.
Cheers Johnnyr
johnnyr is, of course, a Vandersteen dealer and really should disclose that financial interest.

Audioconnection is listed as a commercial user why the beef?
A reader must actually check his registration to know that; nothing in the post indicates a commericial enterprise.

How's that Mr. Lightweight?
As somebody exactly said- the xover must be built for Accuton, not drivers implemented in xover topolygy. that prevent from using some most interesting (sonicaly) xovers. other than that they are great drivers. i worked more than 2 years with accuton and audiotechnology (both very diferent yet very good drivers) the funny thing is to meke speakers sound neutral a diferencies about 4db is a must for theose brands. audiotechnology is lush, fat and "liquid" sounding and regions 60hz/ 100-200 and 650hz needs to be very carefull with not to overbloom sound. and 2nd discortion not so big as it sounds to ears by the way.

accuton vise versa - need to have slight bump is 50/ 100-300/ 650hz to sound balanced. both brands can sound very good. it more in the designer hands than drivers itself.
I have a lot of expirience with accuton .
You already gave the answer , a paper /composite mid sounds maybe a litle more friendly ,relaxing and less detailed sounding .
But my expiriece is at least with my own designs that the ceramic in the tweeter is the main suspect.
A combo with diamond tweeter is hard to beat , and yes maybe one has to adjust to clean high res. sound.
The accuton with the black ears is a very nice made unit with a powerfull neodymium magnetdrive , this high efficiency model makes the design more appropriate for tube designs .
I found a nice paper composite mid and gonna make a model around it for comparison in the future
Most speakers with Accuton drivers don't seem to be efficient enough for a 300B. But hey, I'd love to hear it.
I can design one no problem .
i can design one with 93 real dB s if i have to , mine go perfectly also with the ayon spark 35 watt triode they stay very dynamic .
Mike lavigne has also experimented with real low output designs
The Coincident Pure Reference/Extreme use this driver and work very well with low powered SET amplifiers.
I think that both the Coincident Technology Pure References and Pure Reference Extreme's sound great and they both have Accuton midranges and tweeters, but with Nomex 12" woofers, which are also great. Of course, the skill of Israel Blume in making the crossovers and the cabinets probably has a great deal to do with their extraordinary sound quality, particularly when paired with their own Frankenstein amps and Linestage.

I have Salk SoundScapes with Accuton midranges. Looking at the Accuton driver’s frequency response, I can see how the key to getting great sound from ceramics is a great crossover. Many speakers do not have crossovers that good. My SoundScapes have a great crossover. The frequency response is very flat. They sound very natural. I have the speakers playing all day long and get no fatigue.

My tubed Aesthetix Calypso preamp makes magic with these speakers with Telefunken tubes. They are very natural sounding. The transparency is as good as I have heard on any speaker. That being said, I can see that others might prefer colorations that other cone materials might bring. That has to be a personal decision. My previous speakers had Seas Excel Magnesium midrange/woofers. They added an excitement to the music that I loved. The speakers, that I had before them, had Audax TPX cones. They added a bloom to strings that was to die for. That bloom was not there in live music. You have to decide what you want.

Hi Devilboy,

In response to all the " ceramic sounds hard and thin " comments ,incl my own .

I think its actually a preamp problem not a membrane one .

Get a convergent ultimate mk 2 for example in the system and the hardness will be no longer an issue i reckon
I ran my ceramic drivers on a Bent Audio autoformer passive preamp and my friend runs his ceramic drivers with a music first transformer passive preamp and neither system sounds natural or "organic". I highly recommend a PHY driver if you want those characteristics. My advice: don't be "suckered in" to the ceramics. They fool you early, but prove themselves hard to listen to in the long run.
Andro: I don't think the solution to ceramics is a preamp, (as stated in my above post). They, IMO, are cold and uninvolving.
My ceramic drivers are anything but hard sounding. They simply reveal what's in front of them and they do it exceedingly well.

And BTW, my PHY drivers are sitting in their boxes. My PHYs haven't seen the inside of my listening room since my Indras arrived almost two years ago. If they "fooled" me early, their still doing a good job of it!
Fiddler, not doubting your happiness with your current speakers, but if you have`nt tried the PHY-HP drivers yet how can you reach a conclusion? Do you have the 8' or 12' PHY drivers?

If your ceramics are indeed more natural than a well implemented PHY setup, that`s quite impressive.

My Indras are far more neutral than my PHY drivers. The PHYs are much warmer and not nearly as detailed, nor as fast as my Indras. I consider my Indras to be very neutral and an open window to what's in front of them. It did take well more than 500 hours for my Indras to become as smooth and complete sounding as they are now. Early on they were much more sterile or analytical sounding. I suspect I currently have somewhere between 800 & 1,000 hours on them and they don't sound remotely like they did when I purchased them with about 300 hours on them.

My PHYs aren't even close to my Indras. The PHYs are the 12", KM 30 SAG.
sorry for the typo. Should be, "...they're still doing..."
I can understand why some people find ceramic to be sterile and uninvolving. However, the driver is just one small part of a total system, and with careful component selection, the Accuton can produce a holographic image that is spooky real, with potential for outstanding harmonic textures and clarity. For classical music, they are particularly excellent. There are many speaker designers with many speakers at all levels, so it is difficult to generalize.

Most such speakers require power, so an excellent SS amp or monster tube amp is required. A tubed preamp and gold interconnects helped my system tremendously. I've heard the seemingly most insignificant change, like a different fuse, make my system sound inconsequential and uninvolving. One needs to be open to experiment and build around the speaker. The weak link in the chain will be heard.

I didn't like the all-ceramic Kharmas. They sounded thin and lean, bass was lacking and not real sounding. Combining a ceramic mid with a Kevlar woofer seems to be a great combination. Add a diamond tweeter, and one is capable of the most extended, pure, and angelic top end.
I agree with Rtn1. Although I am biased as I own a pair of Avalon Acoustics Eidolon Diamonds. The Avalons driven by a pair of VAC Renaissance Signature 140's deliver a textured organic sound IMHO. Are they perfect? NO! But they make music!!!
Hi Develboy,
Read and prepare to be enlightened

If they are properly implimented they are not at all sterile. Also note the amps being used to drive them with best results.

Although all whats being said is true in my opinion , they will not sound as fat as a paper/composite mid will .
Good implemented off course , there are more roads to rome than one .
If by fat you mean distorted, then yes, you're correct.
they give more weight to the presentation , more fat , which one is the correct one i dont know
I think the comments about speakers with Accuton drivers sounding thin are due to a preference of speakers that have bloom. My Salks, with Accuton midranges, sound very transparent and have little bloom. I use them in their open baffle mode and use a tube preamp to give them bloom. That is a magical combination. I am very grateful to the quality of their sound. I just want to kneel in front of my speakers and kiss the carpet in worship.

The sound of any good driver depends on the skill of the speaker designer. The construction of the cabinet, the bracing, and the crossovers basically define how well the speaker will perform, given a high quality and suitable amp, pre-amp, and sources.

I have heard a number of ceramic and Accuton driver speakers. Believe me, they don't sound the same. Some are great and some aren't. In the hands of a great designer, such as Israel Blume of Coincident Technology, the Accuton midrange and tweeter drivers sound great in his Pure Reference Extreme speakers. With their 12" Nomex woofers, they are the best full range speakers I have heard. At $26,800, they are a bargain compared to far more expensive designs. Plus, they are very easy to drive, as they can be driven beautifully by Coincidents own Frankenstein 8 watt/channel amp.



The sound of any good driver depends on the skill of the speaker designer


So one can simply use cheapest drivers with small diameter voice coils, small magnets and with a long coil in a short gap and it will still sound great depending on the skill of the designer and the quality of the veneer?

Oh are sounding like a speaker manufacturer!!!!
Rtn1 wrote:
Combining a ceramic mid with a Kevlar woofer seems to be a great combination. Add a diamond tweeter, and one is capable of the most extended, pure, and angelic top end.
Are there any commercial speakers out there that offer that driver combination?
The Accuton drivers when used by a skilled designer can sound very good but they do have some limitations.
- As a dealer we have replaced them for customers but at least they are off the shelf and readily available.
-They have limited pistonic range and require steep filters in the crossovers so can not be time and phase correct.
-As already mentioned the diaphragm has significant ringing with its own sonic signature.
-Need to be careful mixing different materials because of this sonic signature. Best to use the same material 150Hz and above.
Cheers Johnnyr
"Need to be careful mixing different materials because of this sonic signature. Best to use the same material 150Hz and above."

Audioconnection, I don't agree on your last point. My Salks have a RAAL ribbon tweeter and it matches up very well. The sound just gets even clearer and smoother when it transitions to the ribbon at 2k.

I don`t think you read Allchemie`s post carefully. He stipulated a"good" driver(not any driver) and he`s right, a good speaker is the result of the total package, cabinet,crossover design, wire etc. A talented designer given the same parts will produce a better speaker than the less talented designer. Driver choice is important but surely is`nt the whole story by any means.

there are quite varied results with Accuton drivers depending on which designer is doing the speaker building.

Best Regards,

That makes perfect sense, ribbon's ring so its a good match. Its like having a mini reverb on every note. Verrry ooopen and aireeee!
Cheers Johnnyr

For a very short while you had me thinking that you might be right. As a trained physicist, any such ringing would be resonances that would show up in the frequency response curve. The RAAL’s frequency response curve is as flat as a ruler. I am sure that there is some ringing but it must be in the ultrasonic region. Even my dog doesn't seem to hear that high.

I just love all the wrong uninformed posts by those who feel they have a grasp on loudspeaker design. Keep it coming I need some humor.
He stipulated a"good" driver(not any driver) and he`s right, a good speaker is the result of the total package,

Yes, you are correct. I stand corrected. For some reason I read, "any good speaker" rather than "any good driver" - anyway it read like that to bad!
I`ve been very interested in a speaker than uses the PHY-HP 12", do you agree with Fiddler`s opinion that the Accuton is the superior driver(more honest and neutral). My highest priority is natural tone and timbre of acoustic instruments.I`d appreciate your perspective as a speaker builder.
Best Regards,
Charles1dad, I did offer PHY loudspeakers but I do find there to be other transducers that are better sounding for less outlay. That being said PHY km30sag and other PHY transducers are great for acoustic music but to me a bit colored and the baskets causes issues with difraction that other full ranges or coaxils do not have trouble with. I also design with accutons these transducers do require more work with crossovers to get the best out of them but this is common with many modern transducers so not just accuton and to give accuton credit there newer transducers are a bit easier to design with. One can design a good sounding loudspeaker with either. Myself I use massive horns or full-ranges with super tweeters or 2 way ribbon hybrid designs. I tend to be drawn towards lower power amplifiers so this also steers me into loudspeakers that work well with such. If your more into SS or high power tube etc. Then a Accuton equipped loudspeaker might be the better choice. If low power amplifiers and simplicity of design appeals to you then PHY might be a good option for you.
I have two systems, an Accuton based system and a Phy km30-based system. The Accutons are driven by 300 watts tube-hybrid in a large room. The Phy are driven by 10 Watt 300B in a smaller room. The speakers are by Marten Design and Musical Affairs respectively. I listen mainly to jazz and rock.

The Martens excel with all music types, but especially complex music and amplified music (ie. rock, electronica). They are crystal clear, and provide the necessary quickness and slam. I find them neutral in character.

The Musical Affairs are lovely with vocals and acoustic ensembles (small group jazz, chamber music), and some older classic rock recordings. They provide warm full tones and timbres, and surprisingly deep and tuneful bass. However they do not do well with modern (ie. loud/compressed) recordings of rock and electronica. With these musics the rendering is often flat and lifeless. Also they do not compete at the high frequencies with the full-range designs.

This is a classic matchup of medium sensensitivity multidriver versus high sensitivity full-range driver. They are both excellent designs, but quite different in my experience. In the future I hope to compare my Musical Affairs to Horning's Eufrodite.