Found the perfect test for the TB/DJ100. I was just curious again..I guess to hear it lower than 10hz you have to turn it up a lot higher than normal:
http://www.youtube.com/watch?v=ftjZYd5S5gM
http://www.youtube.com/watch?v=ftjZYd5S5gM
Headphone Reviews and Discussion - Head-Fi.org
The only part I don't is that I think their low bass extension is very good and better than advertised (10hz - 25khz). I've tested this and it actually goes down lower than 10hz. So does my KRK KNS-8400 (which is another that claim is bass light). These actually have better low bass extension than my HD-600 and Q701, but that's not saying much. The bass on mine is very, very accurate and won't magically make a song bassier than it should be. Maybe very slightly. I do agree that it won't be good enough for semi bass-heads.