The system calibration should help with this primarily - you calibrate the system for an even response from all channels, including the sub, so that you don't have that problem. Movie soundtracks get the vast majority of their deep rumble from the LFE track, whereas music (aside from pipe organs) rarely dips below 50Hz or so. If you are still worried, you may be a good candidate for the 990's two-channel sub offset - this is a feature that allows the sub to be tuned down a few dB (up to about 6dB of reduction) when in any stereo mode. I use this with about a -2dB adjustment for music listening.