The Headphone Driver Pics Thread - Page 10

Any one next ? Any chance buy normal quality 701 ? I need one.

Ohhhh :o(  http://www.akg.com/forum/index.php/topic,3098.0.html

China

Hi, I have same problem :(. I bought K-701 on thomann.de

akgfan: is 26 mm the exact measure of the K242 HD and K530 drivers? Judging from the AKG manuals it should be the XXL driver, but it's not exactly big. Maybe the AKG engineers have a weakness for irony.

The picture a few posts back is from my AKG K3 manufactured in the beginning of the 1980s. Diameter 27,5 mm. This is how it looks from the back:

It's only 7 mm thick and, as you can see, fairly open.200 ohms.

MDR30: It's hard to measure it right because I can't and don't want to remove it. But the inside diameter of the grid is 26mm. Yes, varimotion "xxl" is a joke and they use it in eight (?) headphones now. There are much bigger drivers, like 55mm and k701 have 40mm?

But you can measure the back of the capsule, it'd just be interesting to know if this driver is derived from the K3 driver.

MDR30: Looks like it has 30mm from the inside. When I look at the diaphragm it is a bit more in diameter than that protection grid, so it must have more than 26mm. But only a wee bit more, no big deal. Probably 27mm or so, but I can't be sure, just guessing.

AKG K400, transparent and quite stiff membrane. This is the DKK 45 capsule, 45 mm wide.

K701, DT880, Japan 70s - but which one is the last?
 

Quote:

Originally Posted by MrJohnny 

Now it brings back a memory - crystal telephone microphone. Right?

Quote:

Originally Posted by MDR30 

Now it brings back a memory - crystal telephone microphone. Right?

Granular carbon telephone mic.
 

AKG K50 from 1959. "World’s first supra-aural, open-back, lightweight headphones." (AKG web site). Diaphragm 22 mm, voice coil 11 mm. Note that it's cone shaped, like a dynamic loudspeaker.

Modded MDR-F1 drivers(foam taken out from back of drivers).

Very interesting. That white paper ring is the "bass lens" - plan to remove it? And the 12 ohm impedance filter? My theory is that the elastic cloth cover damps the treble response, but I have not yet started to modify my FR1, which I think has an outstanding soundstage.

If you go further with the mods, start a new thread. Good luck!

Quote:

Originally Posted by MDR30 

Very interesting. That white paper ring is the "bass lens" - plan to remove it? And the 12 ohm impedance filter? My theory is that the elastic cloth cover damps the treble response, but I have not yet started to modify my FR1, which I think has an outstanding soundstage.

 

If you go further with the mods, start a new thread. Good luck!

I've read a lot about the MDR-F1 and have experimented a lot with it. Removing the bass lens(there's two) will kill the bass response. Actually the resistor in the picture is not part of the circuit in the headphone, I just soldered the wire somewhere else to exclude the 22 ohm resistor. I've removed the other resistor as there's no way of avoiding it. The cloth cover, as you've stated, does dampen the highs. Removing the thin acoustic foam from the back of the drivers really made the soundstage and instrument separation better IMO. 

I've also done other mods but since the F1 is not a popular headphone due to being rare, I decided not to make a thread about it. If you want to know more just PM or ask me in this thread.

I'd just be curious to know how it sounds after the mods (did you leave the bass lens unaltered?), and how you'd compare it to the stock version. Did the transient response improve when the impedance network was bypassed and are you happy with the treble balance?

The FR1 is certainly not common, but there are quite a few owners out there and I think it's still manufactured. We'd be grateful if you'd share your experiences with us.