I would suggest making sure your speakers are well away from the side walls (shouldn't be a problem with your room) so the reflected sound shows up at the listening location with sufficient time delay to avoid smearing of the highs. I have avoided WAF unapprovable room treatments in this way and it works OK. Then....trade off the NHT. I found them terribly bright and if you still have brightness issues with Classe and cardas i don't think a tube pre-amp will save you. My 2cents anyway.