I am not sure how you would go about creating the test disk, and would be interested to know what solution you come up with. Regarding processing your music, there are two opensource packages that I have been playing with to try digital room correction. The packages are Brutefir - http://www.ludd.luth.se/~torger/brutefir.html and DRC - http://drc-fir.sourceforge.net/. Basically you would take sweep measurements at the listening position and from it create a filter for each channel that is used to process the signal to smooth out the room response anomalies. I find this works pretty well in smoothing out the bass and fleshing out the midrange in my system, as I have a wicked room hump at around 40hz and some dips around 80hz. You can set target response curves and I have found that I can get a reasonably flat response down to 25hz with a single well positioned subwoofer. The drawbacks are that the software is not easy to understand and implement, and there is a bit of a processing lag when the filters are in place. The processing lag isn't a problem for me because I only use it for music and I am not syncing a video signal. Alan ----- Original Message ----- From: badgers <badgers(a)daugird.com> Date: Sunday, March 19, 2006 9:35 pm Subject: [linux-audio-user] rezound, test disk and subsonic filter To: linux-audio-user(a)music.columbia.edu