HD555 foam mod

I decided to use some of my incoming holiday money on a new set of headphones, now that the ear cushioning on my HD485 has completely worn away.  I agonized for a long while on whether or not I needed to spend the money, considering the 485 still sounded great, and was simply uncomfortable to wear.  During that period, I naturally missed an Amazon lightning sale of the HD595 for $95.  So I ended up buying the HD555 (Sennheiser has earned my brand loyalty) at the same price.  According to design specs, it's basically the same headphones with marginally less frequency response, and since I'm not an audiophile this seemed acceptible.

Well, they arrived today.  I understand that most high-end headphones have a burn-in phase, but I was dissatisfied with the bass.  This is perhaps a result of having proper ear cushioning so the driver isn't sticking directly into my ear canal, but the sound seemed rather dead on the low end.  My 485 shakes my skull, and as with most forms of change, I was unhappy.

Some google searching later, seeking validation for my grievances, I discovered that somebody in the world of headphone hobbyism had devised a quick-and-easy mod to transform the 555 into a 595.  Apparently the audio drivers on both models are identical, and the cause of the 555's restricted response range is because Sennheiser glued a strip of high-density foam onto the mesh behind the driver.  Supposedly, this foam deadens the bass and inhibits incoming airflow, which fucks up the "soundstage" (the positional framing of sound, i.e. whether the origin seems like it's inside your head or positionally outside your ears) and doesn't let sound "develop" like sound waves are a fine aged French wine.

I watched a how-to on Youtube.  Thanks to the HD5-- series' modular design, every component of the headphone is removable and replaceable.  It was a simple procedure of prying off the foam cushion ring, then the inner mesh shield, unscrewing three screws, and lifting the driver assembly to reveal the interior side of the exterior mesh shell.  And sure fucking enough, a giant foam strip, 1"x2", was sitting right there covering maybe 60% of the available intake holes.  I peeled them off and reassembled both cups, and fired up some Pandora to test the difference.

NIGHT
AND
DAY

Holy shit, they sounded amazing.  The bass was hugely improved.  There's a little more leakage, since these are open headphones and you can hear from the exterior, but that's a small price to pay for performance.  I wanted to be shocked that Sennheiser is intentionally retarding their midrange model and jacking the price on the higher end of the series, but this is a standard practice for certain models of multicore CPUs too.

If my dad is to be believed, my sister is getting me the 595s for Christmas anyway, so I guess I'll be able to make a direct comparison in the near future.