TOPIC:

Where can I find instructions on how to set the compressor?

The nanoAVR user manual has a bit more info than the PWR-ICE125 manual, might be helpful? I'd assume it's the same code. www.minidsp.com/images/documents/nanoAVR%20User%20Manual.pdf

If not, perhaps it would help if you posted more about what you are wanting to do?

Thanks
That helped a lot. The link to Wikipedia was also useful. What I want to do is to protect my subwoofer from very loud low frequent sounds. I use it for music through the digital input with no compression, but for movies and TV I use the analog input from the sub output of my receiver. Movies like Tron have extreme amounts of very load low frequent sounds and I'm afraid that the woofer could be damaged by the long excursion. What I'm looking for is the optimal compression setting so that the woofer does not exceed the 14.3mm excursion, but of course I do not want too much compression. BTW I have set the XO to 15 Hz / 48dB/oct HP and 70 Hz 48dB/oct LP. I have also applied some EQ to extend the LF response, since I use a 12" Dayton in a small closed enclosure.