HD 250, K240, K280, SR125 Measurements and Impressions

So on craigslist I just got this lot of headphones, 1 pair Sennheiser HD250 Linear MK1,2 pair AKG K240 Anniversary Edition, 1 pair AKG K280 Parabolic, 1 pair Grado SR125.

After a bit of cleaning, I decided to do some listening and some measurements.

Sennheiser HD250: I measured my old pair, as the new pair needs new pads. I put a bit of felt in front of the drivers, that's it for modding. Lots of info about these though in other threads, so I wont go to deep. They were my main and basically only headphones before though.

AKG K240 Anniversary Edition: May be different from the current AKG K240, not really sure. Released for AKG's 50th anniversary in 1997. Sound pretty good, but pretty big bass rolloff. Could be from old, flat pads.

AKG K280 Parabolic: Weird looking, 2 drivers angled towards ear, and weird plastic diffuser part sticking out. I am using Audio Technica Velour pads on these, as the flat pads on them were unusable as the weird plastic piece stuck out further than the pads. With the new pads they are very comfortable. Lacking bass, probably would be better with different pads. More experimentation to come.

Grado SR125: To come. Pads were destroyed, ordered some new ones.

I also included a measurement of the equally vintage (though mine are a new pair) Koss porta pro for reference, as my measurement system is not perfect (just some leather, felt, and a lamp I made in middle school)



Measurement rig:


Weird K280:




More to come as I listen more and try some mods.

 

Interesting. Did you made some more measurements/mods/impressions?