Which Proac would sound better

Go for the D38. An absolutely wonderful speaker. They should integrate well in a room of your size.

Have you considered the Wilson Benesch Curves? In the 8k range...I have heard these speakers with Levinson pre/pro combination, Ayre Universal player, SME 20/2 turntable, Audio Research phono preamp. Very sweet system...and this was in an acoustically correct room about the size of yours. You will not find alot of reviews of the WB Curves...the best way to know is to demo them yourself.

In your price range, you might also want to check out a used pair of Wilson Sophia 1s or a new pair of Proac D38 (I do love the Proac sound!).

Best of luck.

My best bud has the Response 3 driven by top notch ARC tube gear and a topflight analogue front end. Great speaker but dated. Will probably require refoaming the woofers at this stage. A very nice speaker and a great bargain (can be gotten around 2K at this point) but if you have between 5-8K to spend the DA-1's are soooo much better. So are the D38's (but not the D25's). Why not consider the 3.8, which can be gotten around 4K and is nearly the equal of the D38 and way better than the D25? Of course, all IMHO.

consider the response 3. i think it's the best pro ac ever made.

I've auditioned both extensively and had a pair of D25's in my system for several months. The D38's are far better than the D25's but may be too much for the size of your room. If your current speakers have "too much bass" then I wouldn't recommend the D25 since that speaker does not perform as well as it should in this region. The D25 has a bump at the bottom end of the range which tends to slow things down and add excess weight. No matter where I put them I wasn't satisfied with the bass performance of that speaker. FWIW, I have a great room and have never had the kind of bass anomolies I experienced with the D25's. In your price range I would strongly suggest you check out the Daedalus DA-1. I own them and they are the best all around speaker I have ever heard below 12K. They will simply embarass the D25's at the same price and will easily hold their own with the D38's, which are far more expensive. Be prepared, however, the DA-1's sound like live music while the Proac's sound like nice hifi and as such may not be your cup of tea.

I have heard the D25s in several systems, and really enjoyed their performance, but none had the specific equipment that you own. The D25 has excellent bass extention, smooth midrange, and nails the highs. Very impressive, and it would certainly be on my short list to demo when it comes time to upgrade from my D15s.

Best of luck.