I've owned a Monster, Panasonic and a Radioshack cassetter adapter and I just bought the maxell adapter and here's my review.  First off I also have a LOUD HUMMING sound coming from the adapter that I don't get from the other 3 adapters. Not so obvious when you have the music turned up but definately obvious when you are in between tracks. I was pleased to see that it has dual magnetic heads like my Monster adapter but it produces very low pre amp volume thus requiring you to turn up the volume and getting the loud humming.  There is absolutely no lower end bass unless you crank up the bass on the tape player.  The mids and the treble sound fine though.