>Now this lack of high end was it on or off axis? If you took a look at the M7's frequency response you'll see that above 8khz the top end's polar pattern becomes extremely narrow. Does the original capsule have a peak or lift in the top end? At what frequency? Could this lack of top simply be a reduction of this lift? A U89 sounds very dull compared to a U87 but in fact it's frequency response is flatter. Once our ears hear something bright everything less bright sounds dull.<
Tim,
I tested it on-axis with close micing. In fact, I compared it to M7 in my UM70, but I payed attention that both its sides are different, so I have to check what is the problem, first. Also, the electronics and grill are different, so it is not a fair comparison.
Right now we have visitors untill the end of this week. After that I will run and record all of the tests with pink noise, and see on spectrum analizer what ACTUALLY is going on.
>Have you tried achieving the same effect by placing thicker spacing matierial between the two halfs of the capsule as you mentioned before?<
No, not yet, but I will. There is one, as I think, very important detail. The K67's spacer between backplates has a slot, so it is not an "O", like this of Chinese capsule, but "C". Isn't it for "capsule breathing", Oliver Archut mentioned on Klause's forum? I will definitely try to do the same for Chinese capsule spacer. Also, I need to check if the thickness of Chinese spacer is the same as of K67.
Meanwhile, I got back "Microphones" by Robertson, and "Elements of Acoustical Engineering" by Harry Olson, so I gotta do some homework.
Gus,
I will measure the screws later tonight. And please report back your second listening impression. BTW, did you pay attention that the output was noticably higher?