Accuton vs Audio Technology

[bssk]

I am building a 2 way monitor. I wanted to know which of the mid/bass drivers are better: Accuton OR Audio Technology. Suggestions please.

[ScottG]

http://www.soundstage.com/revequip/verity_sarastro.htm


"Where these two titans differed most was in the area most crucial to me -- the midrange. While the laser-cut ceramic midrange driver in the Kharma speakers provides images with pin-point accuracy, great focus and startling detail, the Sarastros’ midrange was harmonically richer and, to my ears, more tonally accurate. Thankfully, this harmonic purity isn’t delivered at the cost of resolution. Over the years I have noticed that ceramic midrange drivers like the one used in my Kharma speakers can ring at certain levels, leading to listening fatigue at loud volumes or over extended sessions. However, this never occurred with the Sarastros. On the vast majority of the 60-70 CDs I used to compare the two speakers, I preferred the silkier and richer midrange of the Sarastro. Voices, strings, and brass instruments all had a huskier, earthier, more organic presentation through the Verity speakers that gave music an immediacy that was both enticing and compelling."

Note that the mid ceramic he is referring to is NOT the same as the new neo motor ceramic driver. THAT driver should have considerably less "ringing" due to the two circular dampeners in its diaphram.

[Tenson]

The Audio Technology drivers are cheaper than that new Accuton though... You can also choose the parameters of the Audio Tecnology drivers.

I notice the Accuton drivers all have a grill built in, is that because the diaphragm will brake with the slightest touch? Is it possible to remove the grill?

[Curmudgeon]

In the Great Project, colleague and I spent quite a while looking for the right mid. Scanspeak Revelator 2905/9900, and 25W were successful first tries, but the mid search took a long time. Not least because we were insuffficiently immaculate in crossover component choices and construction technique. However....

We spent perhaps a year messing with the Accutons. These were not the current version, but the previous one, with the asymmetrical damping pad. We were pretty well committed to using low order multislope crossovers, and we never got the Accutons to sound really clean. Other problems were some dynamics compression, and one broke for no apparent reason. We found that removing the grille helped, both audibly and measurably. On ours, it just pulled off.

Later we would have been able to get a clean sound, from what we learned, but the compression would not have been solved.

On the other hand, our first pass with the Skaaning/Audio Technology convinced us we had our mid; it took work also, being incredibly transparent, but it allowed us to fairly easily clean up our act and use best (affordable) xo components, associated equipment and construction (star ground, good connectors, and silver hookup wire come to mind). We're using the C-Quenze 15 H 52 06 13 SD, with concave dust cap, and crossing over at about 150 and 3950 Hz. It does everything; slight ringing at 3900 is the only vice. Transparent, dynamic, clean, just outstanding. It does require excellent associated components, attention to diffraction, etc. (I understand that since we bought ours, the surround may have been changed, and that there is a Kapton voice coil former available now. )

I've posted a fair amount about our adventures in other threads on these forums. I hope the information there is useful.

[Tenson]

What was the idea behind the concave dust-cap? Was it by special request or was it just how they did the older ones?

I ask because I just enquired about the possibility of building a driver with an 'inverted' dust-cap for one of my projects.

May I see some pictures of your drive unit? If you have one from just above the side so I can see the profile of the cone and dust-cap that would be really good

[Curmudgeon]

Not a very good shot; camera on loan at the moment unfortunately. Let me know if this is not adequate.

[Tenson]

Hi,

Thanks that gives me some idea, but a better picture would be appreciated when you can do it.

Why did you go for an inverted cap though?

[Zaph]

Here you go, it's not big but it's clear. I just finished testing one of these today, Model number 18 H 52 06 13 SD. (underhung, SD motor) I'll have results posted soon, with about 12 other woofers.

[Tenson]

Thanks Zaph,

It is pretty timely you are testing one of those woofers!

I have been considering the possibility of having a unit like this built with a 77mm voice coil so that a tweeter (thinking the SS 3004/660000) can be mounted as close to the acoustic centre of the driver as possible; Per thinks removing the dust cap completely will mess up the response above 800Hz. With the face plate removed from the tweeter it is only 70mm wide, which enables a 2nd order Xover at about 1.5KHz.

I would have to buy one of the woofers and tweeter and try it out to see the effects of the waveguide loading from the cone, but as you have one of those woofers sitting there at the moment…. is there any chance you could mount a similar tweeter in this way and take some measurements?

I realise it is not going to act as a perfect waveguide, but I just need an idea of how much work will be needed to pull it off. Mostly I am not sure of the effects of the gap between tweeter body and cone, since most waveguides mount directly around the dome, not the body of the tweeter.

The throat mounting method is supposedly very important, so it may make or break the idea. If it works I think it has the possibility to be the ultimate coaxial midrange/tweeter.

If you have the time to do a quick experiment like this I would really, really appreciate it!

Thanks

[Zaph]

Originally posted by Tenson
If you have the time to do a quick experiment like this I would really, really appreciate it!

Well, let me ask the guy who borrowed them to me if he minds if I cut the dustcaps off his $500 woofers. I'll get back to you on that.