I recently bought a pair of Sierra towers and am quite happy with their performance. When listening in stereo the detail and the imaging are excellent. However there is a null at 120 hz that makes the speakers sound bright and thin. There just seems to be a lack of warmth in the sound. When I switch to all channels stereo this was no longer the case but the imaging wasn't as good and the bass is a bit boomy. Listing to music is the only time this is in the issue. It doesn't bother me during movies. Currently I have all of the speakers crossed over at 80 hz. Would raising the crossover to 120 hz possibly possibly fix the null? And if so would it cause too much localization of the sub? I know I will need to experiment to see what sounds best to me. Just trying to get other people's thoughts of the situation.