|I personally do find that many headphones start to vary above 8khz in matching, but also at higher frequencies placement and ear canal differences start to make large differences as well.
Tim D, I agree completely here.
|If you want to find out yourself how much mismatch there is, make a tone test throughout the spectrum and throw on a pair of cans. Reverse L/R channels to make sure it isn't your ears. And fiddle with placement to see how much it really matters especially in high freqs.
Done MANY TIMES!
I know I have some differences to what I perceive at 1,2 kHz (seems coming a bit from the right side) and 1,6 kHz (that freq. coming a bit from left side), but that phenomenon is more or less the same when auditioning ANY HI-QUALITY phones. But I know more cheap phones to jerk quite wildly at other freq. areas too, indicating driver mismatch.
I ask: WHY GRADO MENTIONED THAT WHEN THERE'S NO REAL MATCHING TO SPEAK ABOUT?
Other brands don't mention that at all or, like Sennheiser, make sensible statements, like 3dB matching in HD-580 or 1 dB matching in HD-600, (what about Big O or STAX?), not like 0.1 or 0.05 dB like Grado does. I think it's MAYBE possible TODAY? in military areas or space research, not mass (even when not so mass like Beyer or Senn) produced gear like Grado are.