Mdiaz - you are not alone. "Brightness" seems to be Thiel’s Achilles Heel. And saying it isn’t so can bring ire from non-believers. Critical consensus places Thiel as quite flat in response, without the common high-frequency droop, and Jim was adamant to not fudge the response to make them easier to take. But there is real stuff going on there, and that real stuff is central to my present work with rehabilitating classic Thiel designs.
I have developed a long list of upgrades that serve to tame that perceived brightness, and that work will see the light of day someday. But I must say that my first and largest recommendation is to work on your room. People say it, they say it here, and elsewhere, but it is hard to believe how big a deal it is. The reflections and chaos are often full-range, but the most obvious and irritating band is in the lower treble brightness range. About a year ago I spent a couple of weeks chasing weirdness in my playback studio, and when the dust settled the sound was so much more articulate, relaxed and alluring that I barely believed I was listening to the same system. This mitigation work is tedious and lacks the glamor of buying new equipment, but man is it cost-effective and satisfying.
But, even if your room is nearly perfect and you’ve chosen mellow gear, and you avoid over or poorly produced recordings, Thiel may still be too close to bright and forward for your tastes. I am certain that I am identifying causes and crafting solutions. I’ve mentioned some of them in this thread over the past couple of years. There are more. For example, right now I am working with wire. Thiel used an aerospace-grade top notch wire, and that was as far as we took it. Jim would settle an issue to his satisfaction considering hardcore science with listening verification, and then put that inquiry behind him. There is only so much bandwidth available if a one man design house wants to keep breaking new ground. But, I know that he did not consider the transmission line propagation anomalies in the wire runs, nor some of the subtleties of EMF interactions. Indeed those models and science were not very accessible then, and even today remain obscure and fringey. But they are real and sonically consequential, even if not thoroughly understood or modeled. A new wiring harness will be quite different than stock Thiel 18/2 solid in teflon. And there is always more. And as I've mentioned before, I believe the ear-brain is qualitatively more critical of such problems when presented with a phase coherent signal which it accepts and scrutinizes as 'real music'. A book could be written about that.
