I've made some changes to my living room which improved both the aesthetics and the sound.
The new bookshelves (the type you have books in
) have finally arrived just in time for Easter to replace the old one!
With new square acoustic panels the floor (almost) to ceiling is covered instead of leaving the bottom quarter a bare wall. This improves the look and performance for both the front and back wall, especially the the performance of the back wall with panels now having an 8.5 cm air gap added. The back and front walls are now about 50% covered in panels.
The decay time seems seems to be fairly even and lowish but with some issues in lower bass. I should have had the volume higher during measurements and there was some distortions in LF probably due to external noise, but that was something I discovered after I completed the measurements. The XO 90 Hz is cleaner.
I removed the grilles of the front Canton Vento speakers, which improved the sound very much as it became more "open". An A/B testing made that very apparent with some classical music, for instance. This is probably due to the acoustic panels I've added at the back wall, and by looking at the backside of the grilles I wonder if they are intended to be used in rooms with little or no acoustic treatments.
By moving the subwoofer in the back right corner forward to the middle of right wall improved the response very much. A broad deep (21 dB) dip at 42 Hz became a shallow one of a few dB. Other peaks and dips more or less disappeared as well.
A disappointment is that XT32 did not handle front right speaker integration with the subwoofers very well, but looking at mono (the FL+FR sum) it seems to be OK below 120 Hz where recorded material is usually mono as well.