Hi Dennzio:
Two subs are an improvement over one in just about any room, even at low levels. The advantage of multiple bass sources is that it breaks up standing waves that may be present in the bass, smooths the bass by "filling in" dips that may occur due to room interactions, and adds a spaciousness to the whole soundstage presentation. It also adds at least 3 dB more gain in the bass frequencies with 2 subs working together, which can allow you to reduce bass levels and enjoy lower distortion. Two subs also gives you a lot more flexibility in room placement, as you learn to "work" the room for best sound (corner placement vs wall placement, even stacked subs.) With recordings that are not typically multi-tracked studio productions ("multiple-mono"), you will discover stereo bass effects, typically in orchestral recordings with minimal mics used. This preserves phase information, and allows it to be reproduced in your listening room as recorded, with real space and dimension,(an argument against stacked subs, which will not do the space thing.) You don't need monster subs to get all of these benefits; this is a case where 2 smaller and more agile subwoofers can potentially outperform a single large one. Good luck and have fun with it!
