@pops @cascadesphil Thanks for the information. I do like that "laid back" British sound, LOL. I currently have Stirling LS3/6 in my main system and Harbeth P3ESR in another system.
My Thiel 2.3 speakers appear to have the first generation tweeters. They look like these:
In my main system I have Herron Audio M1 monoblocks (recently updated by Keith), Herron VTSP-360 preamp, Sota Sapphire, Herron VTPH-2A phono stage, Roon Nucleus/Aqua La Voce S3 DAC, Marantz KI Pearl SACD player.
My room sucks. I have some space limitations that keep me from getting the speakers too far out into the room, wood paneling, angled ceilings, and an irregular shape. I do have some diffusion and absorption panels, but my system is a mixed home theater / two channel system, so there are also electronics and racks in between the speakers and a wall mounted TV up above. Cabling is all good stuff, but a mish-mash of different brands, some Audioquest, some Kimber (no silver), and Verastarr or Duelund speaker cables. I think the room accentuates any brightness in speakers, and there are a lot of reflection points.
I really love the way the 2.3s sound in my main system until I turn up the volume, then I want the Brits back in.