looking for a chair

I would suggest contacting J-10 of former Stereophile fame to ask about the infamous "ribbon chair" he so foundly chubs up on. LOL.

I use a highback chair in my main system and a lowback couch in my second system and I don't find any sonic drawbacks. I do favor the comfort of the highback chair. I used a Lazboy chair in the past that was covered in a soft fabric and replaced that with a Hjellegarde chair that is leather and the sonic difference between coverings is neglible. My advice, don't worry about the sound. Go for maximum comfort first and you will be on your way to many happy listening sessions.

If you sit close to a reflective rear wall a high back nonreflective chair may have some benefit.

I made the mistake of moving from an old and ugly low-backed chair to a new high backed leather chair ---big mistake. I couldn't stand it and had to sell the chair. The difference was very noticeable. I was more comfortable, but felt like I was hearing sound reflected off of the chair. Cup your hands about 4 inches behind your ears while listening for a similar effect. Now I'm looking for a comfortable, low-backed leather chair. So far, all I've been able to find is the Embassy by Cinematech, but $1700 is a little steep for me to pay for a chair...and then there is the matching ottoman. Good luck in your search.