Let's talk Tweeters!

ATC have built their own tweeter in the last five years. Previously they used Excel and before that Vifa and before that Audax (40+ years of pro audio) 

It took many years years to develop and they regard Excel tweeters as extremely good - so improving upon that was difficult.

The ATC dome tweeter looks much like any fabric dome tweeter however it has NO Ferrofluid and had to be made with extremely tight tolerances in order to dissipate heat (large ATC are intended to play at realistic levels of real instruments like a drum set). A dual spider was necessary to avoid rocking motion which is a challenge in all dome tweeters due to their small size and why the majority use Ferrofluid.

Ferrofluid is not bad but it does dry out with time and changes the response and eventual reliability.

ATC like doped fabric domes and pulp paper or constrained layer damping type approaches to cones or domes. This is because these materials are intrinsically damped and therefore do not "ring" or affect the timbre of the sound reproduced as much as rigid materials. (Of course break up can be issue with softer materials and therefore expensive motors and large voice coils are needed which makes the transducer units overall extremely costly) 

I am not sure if it will ever be made available to the general market and other speaker manufacturers like other ATC drivers.

Feedback is good!

I am sorry if this is coming off as heavy handed. I have seen a number of good threads devolve into "my brand X is much better than your brand Y" or "you aren't getting 4D sound..."

So long as we can avoid that, all participation is welcome, especially from those with first hand experience, including and of course, especially @prof

I would like us to bend towards manufacturing choices and what kinds of pro's cons each has.

For instance, MBL's are pretty expensive, and seem to need lots of room. Just saying. :)

Best,



Erik

erik,

cool.

Sorry I'm not going to be able to add particularly technical info to the thread.  I only had listening impressions to give at this point.

I stumbled onto this thread and wanted to add my 2c.

I'm a horn guy, for mid/hi at least. I recently tried the new-kid-on-the-block ring radiator compression drivers (Eminence) since I'd always wanted to try a ring since seeing photos of the 075 looong ago. I put them on small screw-on CD horns I was using already, replacing a good standard-design compression driver. The results were very good. I won't go back.

As mentioned earlier in the thread, though, they can be overbearing. I used a Nelson Pass 'trick' I already employed on my prior drivers in which it was suggested that a certain resistive load in series with the driver, when using an amp that behaves nominally like a voltage source, will simulate the behavior of a current source. I made no attempt to perfectly match anything; I simply used a noninductive 8 ohm power resistor. As with my prior drivers, the 'edge' was taken off. It's not the slight amplitude reduction nor is it anything I see on a scope (either from the amp or from a microphone), and I don't care whether the amp acts as a voltage source or a current source, but the effect is very pleasing, and the new tweeter sounds better than anything I've used prior. It runs from 2400hz on. The crossover is active digital, a 90db/oct FIR filter, just to fill in the details.