Guess what guys? I got both the AD900 and the Pro700mkII, and I'm sending the pros back. I've found a way to make the AD900s have more bass than the Pro700MKII. Now that I'm listening to the AD900s, there seems to be more of a sub-bass bump than the "bass" bump in the pros. There is more separation in the mid-bass, and the soundstage is larger than the stock pros. To confirm this, I transplanted the working driver in my old pros (the ones I broke), and put it in the AD900 enclosure. Both of them sounded identical, but the AD900 driver sounded cleaner. There was less congestion in the mid-bass, and it sounded more correct, for lack of a better term, than my modded Pro700MKII drivers.
Both of them have a 53mm driver, but the magnet on the AD900 is more open in the center, whereas the magnet on the pros have a smaller hole in the center. The larger opening in the center of the magnet on the AD900s allows for more a more open upper midrange and treble.
So, here's what I did to the AD900s: I gave them much more clamping force, and I put the beyerdynamic gel earpads on them. The stock earpads doesn't create a seal around your ears at all, and there is very little clamp. That's why many people say that there's no bass on the AD900s. You need a good seal and good clamp to get the bass out. The gel pads are perfect for that. I had to bend the wire on top of the AD900s to get them to clamp good, but I'm still trying to work out how to get some more because when I lightly push the headphones against my ear, I get more focused bass.
I used packing tape to put them on since they're too small for the enclosure. Stock AD900 vs modded: MUCH fuller sounding, much more bass, and the soundstage is unaffected. M-100 what?
EDIT: modded pro700mk2 (converted to open) vs modded ad900: ad900 has more control in the lower frequencies, less congestion in the bass, and the soundstage is pretty much the same. Everything else sounds pretty much the same.
modded pro700mk2 (in my sig) vs modded ad900: the same as above but the ad900 has a wider soundstage.
blue box m50s (more bass than newer ones) vs modded ad900: lol
hfi 780 vs modded ad900: roflmao
Now that I think about it, this mod should work with the AD1000, AD2000, and the newer revisions of the AD series headphones.
EDIT 2: I fixed the issue with the bass not sounding focused unless I pushed the headphones against my ears. The problem wasn't clamp, but sound dampening. The bass coming out the back of the headphones was causing the headphone enclosure to reverberate the sound, which made the bass sound kind of flabby. The headphone enclosure, the way it is, isn't made to absorb any excess reverberations from the sound coming out behind the drivers, so I needed to use some kind of material that would help absorb those reverberations and improve the sound: Cotton pads.
I had to get this type of cotton, stab a hole through eight of them (four pads on each side), and stuff them inside the ring thad holds the driver in place. I had to put a hole in it because it would cover the opening in the center of the magnet, thus making the higher frequencies sound vieled. Now, the bass has much less reverberation, and it sounds tighter than it did before. I guess the headphone enclosure wasn't really aimed torwards being bass-centric, so they left out trying to dampen the sound in order to cut costs.
Edited by Trae - 1/10/13 at 6:43pm