Here's one Chinese or Japanese website, i came across it while browsing through the HD540 thread, with pictures and data and such: http://20cheaddatebase.web.fc2.com/sennheiser/sennheiserindex.html

Well I steered you in the right direction, and you found the info you wanted, so just a little searching for yourself can do wonders. :)

Maybe look at open-back planar magnetic headphones, planars are know for their punchy and extended bass.

My rank of open-back headphones that I owned for long enough to form a good view on: 1. HD580 (flat name plate) 2. HD600 3. HD650 4. HE400S 5. K7xx 6. K612, DT880-250 (tie) 8. Philips X1

Well contact Beyerdynamic or one of their retailers, and they'll for sure tell you, or search the website.

There are (fake) leather pads for the DT250 from Beyerdynamic, possibly you can order them on their website. If you live near Germany, i see Thomann has them.

Cool that you can measure them! The adapter is here, and it does sound smoother, like this cable is better wired (that specific tinny sound isn't really there anymore), but yeah still no bass, kinda sounds like the measurements.

Ah okay. Well the pads were completely gone so i put on a couple of DT100 pads and they fit ok but there's still 0 bass, so it's either a really flawed headphone or wiring issue affects the sound so much. I ordered the adapter cable so I will hear soon if there's a difference. How have you used...

It;s a Telefunken th-500, now that i listen again it does sound a bit weird, "tinny", kinda like when you don't push the plug all the way in the socket, so it could be incorrect wiring. Or it could be that's how the headphone sounds. It seems exactly that 5-pin wurfelstecker yes, it's a german...

So I bought an old ~1970s headphone that has a 5-pin connector. It came with an (I think home-made) adaptor to 3.5mm, but when connected (to a good source) the sound is very crappy, telephone-y and there's literally no bass. Do i need a good quality 3.5mm adaptor (where can I get those?), or do...

Philips X2 (or X1) has plenty of bass, and seems to be good for games and movies. It is a big headphone though.

The older pair i'm not sure how old, but was a few years old i'm guessing. The new pairs, especially the Pro model I have right now, has less sharp treble, much more smooth I think. Don't have them to A-B now, but from memory I'm pretty sure there's a differnce. Also a new Edition model i heard...

Are new 880's warmer sounding than older ones or is it just me? I've heard a couple of new DT880's lately and also an older one, and the newer ones all seemed obviously warmer sounding with darker / smoother treble (which is a plus). Maybe newer pads are different?

^Here's a recent review of the 880 (also the all-black one) on youtube:

^Think they're a special edition, not the manufaktur, since the headband covering seems a little different. The metal headband seems the same though, as the Edition and Manufaktur odels. (So I don't think it has the (clampier) Pro headband). So yeah, it's gonna sound exactly the same as the...