I've seen and heard about this many times before and I'm now seeing the value in this because of yesterday's experiment. Yesterday, I wanted to tweek bass in my main system using the bass crawl method. I pulled out a test CD that I burned which had mp3 files of individual frequuencies. All of these frequencies have been recorded with the same signal strength,verified using Audacity. I disconnected one lead from each of the mains, inserted the CD, hit 7 channel stereo, and played 20, 30, 40, and 50 Hz frequencies. I noticed that 40 and 50 HZ locations were louder in different areas of the room compared to that of the 20 and 30Hz which was loudest at the original subwoofer location. If I bought a second Rythmik and put it in the location where the 40-50Hz location was the loudest, then would I would have a more even bass response compared to what I have now? It doesn't surprise me that the bass is loudest with different frequencies in different areas of the room based on wavelength alone.