Quote:
Originally Posted by estreeter /img/forum/go_quote.gif
I know the T40RPMKII isn't well thought of here, but ... the thing that stands out to me is how little fatigue I am experiencing listening to metal atm. ... there is an 'other worldly' quality to them that's hard to describe.
I'll give them a hundred hours or so and revisit this thread - its just too big to read from start to finish !
|
I finally got hold of a T40RPMkII myself and slapped the new-style pads from my T50RPMkII on it and found the sound to be very nice, better than I expected, though the bass wasn't anything to tell the world about. "Polite" is often a pejorative, but in this case it isn't. So I think I understand what you mean about metal vs. softer stuff. There may be hidden depths to the '40 as-is, and it might be a good candidate for the Surgical Transplant style of modding that Smeggy specializes in.
Don't bother reading the whole thread-- read the first [I think it's] 6 pages to get an idea of what the operating principle is and what was wrong with the earlier examples of the breed, then use ludoo's
search engine to pick your way around to answer specific questions, then ask any question that's left over.
Quote:
Originally Posted by DefectiveAudioComponent
The TH700 will most likely [have more bass] with some new pads on. You will also probably need to seal it better to the baffle, if it is the usual PMB work. There is also probably a very thick damping pad inside.
|
NuBreed, DAC's advice is spot on. Any PMB headphone from the early '80s and before has cloth earpads because the synthetic earpad covering ("pleather") has rotted away. Bass does escape from the vents on the back of the earpieces, so a better earpad seal will give stronger bass.
The seal from the driver to the baffle, which must be airtight for maximum bass, is problematic with the typical PMB driver, which uses springy sheet-metal clips or clamps to hold the repelling magnet discs together, and these form a discontinuous surface on the magnet, making an airtight seal more difficult to achieve. In the TH-700, PMB used a narrow circle of foam for a gasket, and this foam, like most foam of the time, has almost certainly deteriorated. Try adhesive putty or RTV silicone. Just as with the earpads, we're trying to keep the driver's bass backwave from coming in direct contact with its frontwave.
The back of the driver has a center electrode in the form of a tiny metal dowel or pin that protrudes. Any damping layer must be in intimate contact with the back of the magnet, and this pin gets in the way. I suspect the thick felt disc PMB supplied is more of a backwave absorber than a damping disc, because my TH-700 sounds about the same with or without it, and the pin pushes it away from the magnet in any case.
It's a comfortable headphone and well-made. Let us know how yours sounds and how well it takes bass boost-- that's a good diagnostic. And of course we'll be interested to see whether the driver looks like the one in my TH-700.
Quote:
Originally Posted by NuBreed /img/forum/go_quote.gif
My friend told me that i can put some wool inside of them, but i think that bitumic tape would be better to decrease space in earcups.
|
Were you thinking of filling the space inside the earpiece with bitumic tape? There's not much space in there to fill. What was your friend's idea?
