For those who have the Beyer T51p, what's the impedance on your cans? My first T51p said 60 ohms on the box. I had to return and replace those because it was defective (headband looked like it was shaped by a poorly trained monkey, the metallic earcup cover had crud and scratches on them, etc.). My replacement cans had 32 ohms listed on the box.
Various reviews of the T51p on the web are inconsistent on the impedance. Beyer's North American website says 32 ohms but the instruction booklet that came with the T51p says 60 ohms.
I wonder what's going on. I'd be curious why Beyer is making 2 variants of this headphone and not giving any explanation. Personally I don't recall any difference in sound between the two. I had to turn in the first pair to get the replacement so I couldn't compare at the same time.
My manual also states 60Ohm, the website now says 32Ohm for both the T51p and the T51i, so I guess they changed that midway... interesting move.
Yes, the nominal impedance depends upon the frequency its measured at, but while it sure can change quite a bit over frequency I doubt that Beyer changed their measurements, they always used 1kHz (and still do with the 32Ohm given now).