Originally Posted by Mshenay
Sheesh, well that's good to know... I honestly don't use a bass boost any bigger than 3 my self so I really have no idea how bad it can make things... thanks for the input
It will depend on the headphones and whether or not the driver was designed to produce low bass output.
I know with speaker and subwoofer design, harmonic distortion can jump dramatically near the driver's limits for the low bass output at or around its tuning point (generally where the speaker is starting to roll off) and get worse the further down you go. See this harmonic distortion plot of the Power Sound Audio XV-15
(taken from data-bass.com
At a 100 db sweep, looks good. 105db, distortion is starting to rise. Then by 110db, it's hitting pretty high distortion in its lowest frequencies--and it's an extremely good, powerful subwoofer meant to get low. To protect it, there's a limiter built into the amp which prevents it from going any louder below 20hz.
Since most headphones have tiny dynamic speaker-like drivers, I would imagine the same might be true. So trying to push a headphone to produce bass well below it's tuning point where it's already say -10 db down to produce an emphasized bass response could easily push it to its limits even though the driver might be below its max with the other frequencies, resulting in very heavy distortion of the bass. And it could possibly even damage the driver if pushed hard enough since there's no limiter to keep it from over driving.
BTW. This is also why I'm impressed by the DT880 and DT990s bass output. It's probably hard to get an open headphone driver to produce such good low bass and still have very excellent mids and highs, and especially when you can buy the DT990 for under $200.Edited by cel4145 - 9/3/13 at 12:37pm