About 6 months ago I found that the Maxell DHP-II's memory foam pads could be used on the DT-235 to convert them from supra-aural to Circumaural.
I found that this made them into one of the most comfortable headphones there is. At the time though I had wished the sound was a little better. It still sounds very good, especially for the price.
For me putting on the Circumaural pads made the headphone too bass heavy! I have no idea how this is possible, but it did. It was so bad that I had to EQ them just to like them. I wanted to see if I can reduce the bass without an EQ (my stupid Ipod Touch has no good custom EQ) and make them sound even better.
I think perhaps the plastic shell hurts the sound quality overall in some way. First thing I did was take a single package of Blu-tack ($2.50 at Home Depot) and put 2 strips in each cup. You don't need to be perfect. One for each side. It's annoying, but it only takes a few minutes.
I then did some crazy experiments with the fabric covered holes around the driver. I covered up 6 with plain masking tape and the headphone suddenly became extremely shouty and hurt my ears. Bass was there, but extremely light. I had to crank the volume up really high. I kind of expected this. Duh.
I then covered 3 holes and it was slightly better, but still not good. It seemed to make them a bit too treble happy.
After lots of experiments I've found this configuration is perfect for me:
Cover up the tiny "vent" hole right above where the wires are soldered in place. Then right directly above the solder points across the magnet cover up only 2 of those holes that are already covered up with fabric. I did the left two.
The mids now are pretty impressive. They're even kind of forward to me, but never shouty like before. All the treble is still there. Bass is still good, but now it doesn't ruin the sound. The sound signature still feels well balanced. Wait until you here the result with female vocals. Jpop and even Cantopop is quite impressive! I think the amount of air the driver gets, the more bass it has. At least with this closed design. Air doesn't seem to go through masking tape. The sound feels more clear and I don't have a clue how this is.
Now I'm about 95% sure this couldn't effect the soundstage, but this headphone with these pads has a pretty good soundstage for being closed.
I tried these with gaming and they're quite good for $50! Did you know that Beyer sells a gaming headphone with a mic that has nearly the same design?
Maxell doesn't sell the pads separately, but the HD-497 pads also fit, but they're much less comfortable and smaller. I believe the HD-497 was replaced by something else. I'm 95% sure the HD-202 and HD-212 pads are the same. If you know how good the DT-235 sounds, the cost of new pads is worth it. HD-497 pads might not be circumaural for everyone. I absolutely HATE supra-aural headphones!
I'd like to compare the sound to the DHP-II. BTW if you thought the Grado SR-80 was a nice improvement, wait until you try this!
I don't know if you will get the same results without the DHP-II or circumaural pads, but it's still worth experimenting. With the default pads I always felt the DT-235 wasn't anywhere near bass heavy.
This is one ugly headphone if you are forced into getting the white pair like me. They make them in black and that version looks much better. Here is the ugly white version with the new pads:
I'd take pictures of the actual mods, but my camera battery is dead. It's actually very easy. Just be careful to not pull out the wires!
To attach the new pads you pull on the earpads and they're attached to a piece of plastic that snaps into place. It's extremely easy to replace the the pads. You need a skill level of 1/10 to do it. The pads wrap around the plastic piece.
The resulting headphone when fully modded sounds better than my modded UR-55, AKG K44, HD-497 and probably my Grado SR-80. SR-80 has less detail but is probably a tad more clear. Possibly better than the DHP-II, but I'm going to compare them this week. Seems like the mids are just as forward as my DJ100, but maybe not. Doesn't come close in sound quality, but still fun to listen to. DT-235 is definitely much brighter. It's also pretty easy now to pick out the garbage tracks in my collection. Make sure you test this out with some high quality lossless files!
This mod is also 100% reversible!
Edited by tdockweiler - 3/6/11 at 8:07pm