Just bought one of these. Returned two of them 'til I got one that sounded decent. Everything in the Horwitz review (bass issues esp.) showed up in two of three units. I have found that the problem is not with the unit, sort of. First, this is an ipod player and I have found that mp3's vary widely in their dymanic range profiles; some are much louder than others, some have more bass, etc. This won't do on this machine. What I did was set the sound check option to "on" in itunes. After the files are processed, I click on music in the library window, then "select all",then "apple-info". You will be asked if you want to edit for multiple items. You do. Check the "eq preset" box and then go to the dropdown menu and select "flat". Do the same thing on the ipod (sound check on and eq to flat). In so doing, the need for constantly fiddling with the controls is eliminated. I press the "R" button on the Tango remote to set the bass and treble defaults and adjust volume to between 25 and 30 (the volume maxes out at +40). That's it. If you like tighter bass, just do what someone else did and stick some damping material into the reflex port. About 10" of foam strip. It works. It might also be a good idea to play at moderate volume for awhile and not try to rock the house right away to let the unit "run in" at first. In the beginning, I said "the problem is not with the unit, sort of". Before I got one I wanted, I opened up one of these machines and found so much excess glue holding the subwoofer flange to the chassis that some of it dripped onto the back of the bass driver cone. Not good. I removed the glob and all was well. Quality control issue. XtremeMac has been informed. Great unit. 'Nuff said.