Tuneslover
Headphoneus Supremus
Has anyone tried to measure the impedance of the HD6XX? I noticed that the HD6XX is a bit more efficient (2-3dB) than my old HD650 and it actually sounds decent with a old 4th gen iPod touch or Fiio X1. It could be that a slight difference in the impedance of the HD6XX is making it sound a touch brighter, slightly more detailed bass and better dynamics.
Ruled out the cables since I swapped the cables around just to check.
I also wondered whether the HD6XX was a bit louder than my HD650 when I was comparing these headphones on my Lake People (with 2 headphone output) amp. So I decided to use my Radio Shack Sound Level Meter to compare loudnesses. I admit that I did not employ a very scientific method of comparison because I simply repeatedly moved the meter between headphones and observed the readout. Based on this method I didn't notice any obvious difference in readout in output levels. In the end I assumed no discernible loudness differences. However, the HD6XX did sound mildly clearer in the upper frequencies. Swapping ear pads between the headphones narrowed the auditory loudness difference but even then I still sensed a slightly clearer sound from the HD6XX.