Holy Cow!! So I've done the Bass mod on several 428's before, nothing really new there. I've also modded my 439's before, no biggie right? Well every time I've done the Mod I have only opened one hole on the tape. So I scored another 439 off ebay for 38 bucks. Not a bad deal, they looked basically brand new. So I said eff it why not mess around with them??? I opened them up and pulled off the whole tape strip. Put them back together and cued up some Marley. OMG!!! These suckers have more Bass then the DT770. It is truely earth shaking. It hits so tight and deep the cans are shaking on my head. It is insane. What's even more crazy is nothing else is smeared up. The mids and highs are right where they should be. And the soundstage even has more depth!!! I think it might be too much for me really, One hole has always sounded pretty dang good to me. I haven't done a straight up ipod test, I'm running these amped thru my M-Stage so that could help out quite a bit, but my god!!! I don't see how so many of you Bass Heads can take this: This is crazy Bass levels!!!