A better tweeter for my AP Avanti IIIs

[jeffreybehr]

I have a pair of Audio Physic Avanti IIIs, introduced around 2000 I believe. I bought them the summer of 2010, and their high sonic quality motivated me to improve many other aspects–parts in the preamp, all front-2-channels' ICs, poweramps, vibration control, etc.--of my system. It’s now sounding MUCH better than with the prior speakers.

I’ve since improved the Avantis greatly, outboarding the x-over boards, rewiring all drivers with much-higher-quality cable, removing inexpensive plastic-film MR-hi-pass caps from the x-over board and ‘replacing’ with smaller coupling caps in the amps, replacing all the MR and tweeter caps and resistors with much-better ones including huge Teflon-film caps in series with the tweeter, and tossing the bass x-over and replacing with separate monoamps driven by an active digital filter. I’ve added different, better spikes and diffractionbegone.com antidiffraction pads around the tweeters. The quality of the MR--and with the different coupler/MR-hi-pass cap, the MR drivers run from c. 80Hz to c. 2.5K, about 1-1/4 octaves further down than originally--is now simply excellent, the best I’ve ever heard at length from any system. The treble, however, improved from good to ‘just’ very good. (The newish poweramps, Monarchy SE-160s, sounded very good to me when new and stock, and I’ve started improving parts and sonic quality in them and will continue to do so.)

Yesterday I listened to two pairs of Vandersteens, the Quatros and 3A Sigs. The Quatros had slightly-better-quality treble and about-as-good MR, while the 3As were good sounding but not great-sounding anywhere. Got home and immediately listened to the same recordings--mostly SACDs--and was astonished as just how great the Avantis’ MR sounded but also how slightly coarse the treble was.

I’ve convinced myself that I can’t afford to buy a better-overall speaker system, so I’ve decided to improve the treble from the Avantis. Since this speaker was designed around 1999, I believe it ought to be easy to find a better-sounding tweeter than its 1"-ring-radiator, pointy-phase-plug model of indeterminate brand, but...

Of course there are physical constraints to replacing the Avantis’ 104mm-plate-diameter tweeters. I’d like to use the RAAL 70-10 ribbon, but it simply won’t fit, nor will any other ribbon tweeter I can find. I’m down to two Scanspeak 1"-ring-radiators with 104mm plates, the Revelator R2904/700009... https://www.madisound.com/store/prod...oducts_id=1581 ... and the Illuminator R3004/662001 ... https://www.madisound.com/store/prod...oducts_id=8518 . For various reasons, my slight preference between these two is the more-expensive (c. $350) Revelator. I’m also considering a couple Accuton 1"-ceramic-dome models, the C2 12/6 from Sonic Craft ... http://www.soniccraft.com/Drivers/Accuton/c126.htm ... and the C25-6-012 on Accuton’s site... accuton® Carefully selected loudspeaker drivers. . (For all I know these are the same but with a newer model-numbering system.)

I understand I’ll have to create the x-over, and with a single-order MR-lo-pass filter, I’d like to use a single-order hi-pass on the tweeter.

Any thoughts on my dilemma, choice of candidates, recommendation for other candidates, etc.? I’m especially hoping someone can opine on the quality of the Accuton’s treble, as (I think) I’ve never heard them.

PS. I considered building a 3-way system using excellent-quality drivers, but on the 10-scale of speaker-design knowledge, I’m at about 0.1, and I think it’d be a 2-year project that I still wouldn’t be happy with.

[jeffreybehr]

More thoughts.

Since I'm determined to at least start with a 1st-order hi-pass filter on the new tweeter, I'll determine if I can raise the lo-pass filter point (FP) of the MR driver, currently 2500Hz (I think). If that driver will still sound fabulous at, say, 3K, the 1st-order filter on the tweeter can be higher than with the original MR FP.

Also, I've determined that I can squeeze the RAAL 70-10 into the baffle with some modifications to both, so I'll be ordering one to experiment with.

[jeffreybehr]

Prior to the Avantis, I had DIY open-baffle linearrays, and the last tweeter I used was a single B-G Neo3PDR mag-planar. I sold those to a friend, and Saturday I borrowed them and clipped and taped them into/onto the A-IIIs. I am now finished looking for better-sounding tweeters. Massed violins no longer sound slightly coarse, and hard-blown trumpets are no longer slightly edgy.

The Neo3PDRs work VERY well with the A-III's 3rd-order crossover, at least according to my 3rd-octave RTA and ears. They need a little level tweeking, being about a dB too strong for most listening. Probably I'll redo my tweeter-level switch and use 2 resistors for 1 and 2 Ohms of resistance prior to the filter. I removed a small amount of material from the tweeters' bottom corners so they (mostly) fit into the 104mm recess, soldered and taped them in, reattached the diffractionbegone.com antidiffraction pads, and I'm finished.

I did nothing to the boxes, so everything's reversable if someone wants them original.

Not bad for $115!!!!!!!!!!!!!!!!!!



BTW, altho the MR drivers appear to be identical, they're not. The lower driver has only one magnet, while the upper has two. The lower also had a 500Hz lo-pass filter instead of the upper driver's 2.5KHz (or is it 2.2KHz?).

[piolaxo]

They could be the same, just that they added an extra magnet to the upper one to add more sensitivity. The crossover is just to make them 3.5 speaker system. Nice design.

Were you able to try the RAAL to fit there?

[Inductor]

Also look at LCY drivers, LCY-K100, LCY-108/110, LCY-130.
Welcome to E-Speakers.com - Very High End Loudspeaker Components
Ribbon Tweeters: Madisound Speaker Store
LCY-130 is on the new Mowgan Audio Etain loudspeaker.
(Hi-Fi World August-2011)
http://www.lcy.com.hk/home.php

[jeffreybehr]

Didn't buy the RAAL; was happy with the B-Gs. Soon after all this, I bought a pair of Vandersteen 5As and, after improving very few parts in their rather-complicated crossovers, I'm finished playing with speakers. Now I just listen.