I purchased a pair of used 3.6 speakers a few weeks ago and try as I might, they are just too bright to live in my system.
I first drove them with Herron M1 150 watt monoblocks. I bought a pair of Ampzilla 2000 Second Edition monoblocks to see if they would sound better with more power. The dynamics improved, but they still sound bright. The Ampzillas are rated at 300/540 into 8/4 ohms. Stereo Magazine measured them at 390/680 and they are supposed to be stable into 1 ohm.
I put my Harbeth Super HL5 Plus speakers back into the system and they sound sublime with the Ampzillas. They had a little bit of a hard edge at times with the Herron amps, but that is gone with the Ampzillas.
My room is less than perfect, and could be contributing to the issue. The right speaker is near a side wall, but the Harbeths as well as my KEF Ref 1 and Stirling LS3/6 speakers all work great there.
I really like everything about the 3.6s except the brightness. If I could tame that, they might knock out my newer and more expensive speakers.
My options for placement are limited and I'm not going to spend even more on amplification for 20ish year old speakers. I had them about 9 feet from my listening position and just slightly toed in.
If there are other suggestions to tame them, I'd love to hear them. I've also reached out to Rob at Coherent Source Service to see if he has any upgrade or mod options.