Bill Epstein Messages: 1088 Registered: May 2009 Location: Smoky Mts. USA
Illuminati (2nd Degree)
Your complaint reminds me of the Piezo tweeter days. I'd look at the room.
The Vifa XT 25 tweeter is 2 dB less efficient than the Alpha 8 as Wayne said and, compared to other domes, is in the less-fatiguing/detailed camp. The Zaphaudio test called it "the smoothest and most extended response curve....".
Get some good room treatment advice at the Rives Forum; for instance, 1" thick stiff fiberglass (Owens-Corning 604) panels offset from the wall 2" will attenuate frequencies from 1500 Hz up. Add drapes, try live-end, dead-end, move reflective surfaces like glass-covered paintings and mirrors, etc.
If you must re-cap, I'm a big fan of the copper Obbligatos as well as old Aerovox motor runs in the oval cans. Use'm in all my stuff.