Currently have Thiel CS 2.3s driven by Krell KAV-300iL with Audioquest CV-8 speaker cables.  Front end is Oppo BDP-103 used as transport, PS Audio Perfect Wave DAC and Bridge II, working on converting cds to NAS, running Roon and Tidal.  PS Audio UPC-200 for power, AC cord for Krell is an Audioquest NRG 3 with 20 amp plug, converted to IES with Black Voodoo converter.  Silnote Morpheus XLR cables.  Room is 11.5' x 22' x 8.5', no treatments yet.

Loving this system so far, have greatly enjoyed each improvement.  However, I am looking to improve highs which sometimes lack crystal clear clarity, especially when the music gets complex.  Also would like to improve the vocal/midranges, make these warmer and deeper.  What should my next upgrade be? I am thinking that a significant improvement is going to cost $2000-$3000, in the meantime I was going to try some DIY room treatments. 

Background - dove into two channel hifi at the beginning of 2018, goal was to put together a decent sounding system in a dedicated listening room using used, discounted, even vintage equipment, all for less than $5000.  Geoff Poor at Glenn Poor's Audio and Video in Champaign IL demonstrated the magic of time and phase aligned speakers and after some research I Ianded on the CS 2.3s.  I had been using my brother's old Maggies and had already purchased a Krell integrated amp for these along with Audioquest cables, also had an Oppo universal player from an old HT set-up, so that's where I started.