More information you may need to formulate an opinion:
All Focal Utopia Be speakers operate the same tweeter at a crossover frequency of 2500 Hz and 24 dB/octave, from Micro to Grande. All Focal Utopia speakers have a minimum impedance around 3-4 ohms, with the exception of the Micro which is published at 5 ohms (maybe it really is lower). 6 ohms is nominal min impedance for a nominal 8 ohm speaker, so 5 ohms is actually close if it is actually the case. I did not see Stereophile's complete review and measurements.
The Red Wine amp is quite capable of driving 4 ohm speakers and has more current on hand for more punch with higher damping factor than about any other amp out there. It may not hold up continuously, but surely it will do so for a long note. Listening is convincing enough.
I was able to clip my amps very audibly in the midbass where most clipping happens in full range speakers and not hear it in the tweeters.
I changed the frequency of operation from "full range" to the Focal "satellites" to a 6 dB/octave rolloff starting at 70 Hz and sent 70 Hz on down to the sub. This increased dynamic range for the satellites.
Does it get to 103 dB at 1m? No, but in an ideal world it could. 30 linear watts should get me 14.77 dB above 1 watt. And 89 dB/1W/1m should get to 103.77 dB/30W/1m if uncompressed. Add a nominal 5 dB compression and there's the peak before clipping: 98.77 dB output 1m back from each speaker. What's that at the listening chair? Too much to calculate, it would need a special quasi-anechoic measurement. With that type, it should be circa 95 dB at 2m back peak output, both speakers driven. It should then be playing at a max approx 85 dB median volume level.
All that is still loud enough for me. At 10W/ch it drops to a median 80 dB max plus the lesser compression and at 100W/ch it raises to a median 90 dB max minus more compression. I know it's not the 100W/ch amp that was clipping, although not paying attention might make me believe I was doing it all the time at 30W/ch. If it clips at 30W/ch why is all the clipping happening at 6-8 KHz in some resonance fashion and nothing in the bass? It's a harsh ringing tone of dome break-up sound, not hard clipping hash or soft clipping hash.
Dropping the low frequency -3 dB cutoff to "full range", 50 Hz, compresses the woofer more, but is less at 70 Hz.
In the Diva Utopia, the midrange is exactly the same driver as the bass driver in the Micro Utopia. And when applied there, that midrange is operated 100 Hz - 2500 Hz where I operate it at 70 Hz - 2500 Hz. It would appear to me that I should have very close dynamic performance as the Diva. Is that bigger sounding? I don't know.
There's one thing I believe in most from all the info put forth and from my experiments. There are brightness difficulties associated with this tweeter at higher than average volumes that is occurring through resonance problems just like beryllium horn drivers also have. And it's not at ridiculous levels, just the higher volume end of listening. Listen to horns do that horrible harsh ringing at a live event PA address system some day and it's not killing the tweeters there either. It's driver modal breakup and resonance. And it hurts my ears every time. So I avoid those situations.
I would not try another amp change. I already did that once. I would either learn to listen always at moderate levels even if the dynamics of the recording want to go high, or look for another pair of speakers once again. And that is going to be challenging.
Perhaps DeVore, since those are favored by the owner of Red Wine Audio for his amps.
Thanks for everything. I hope this discussion is useful. I think it was for me. I don't feel my theory was destroyed, so I can act more confidently in my next decision, whenever I can afford that.
Kurt
