opaqueice Wrote: > > > First, to characterize the original difference more, there is a loud > buzzing sound with both polarities, but underlying it there seems to be > a lower frequency, more pure-tone sound. It's the pitch of that > subdominant sound which changes or seems to change between the two > polarities. > > With the phones reversed (each speaker facing away from my ear), it's > much harder to hear the pitch of that lower sound. I think I can still > identify it, and it seems to be the same as with the phones in their > ordinary position, but I'm really not sure. If so, that would support > distortion in the electronics and/or speaker cones over some physical > effect in the sound waves themselves. >
The low frequency response of headphones is critically dependent on the seal that the earcushion provides against the side of one's head. If you are simply flipping the drivers over on the bails, you no longer have a cushion sealing the driver to the side of your head and the sound will change. The change is more complex than just rolled off low frequency response. The sealed/partially sealed chamber formed by the driver, earcushion, and side of your head also has its own resonance that contributes to the response. Unless your speakers are dipole radiators, listening to the back side will not change the polarity of all the audio. If they are dipole radiators (such as full range single driver ESLs) the polarity IS reversed, but in the reflective environment of a normal room, what you hear is always a summation of the front radiation + reflections of the front radiation + reflections of the rear radiation. As for DC offsets in music, yes, they sort of exist. Music contains many even order harmonics which by definition result in assymetries of a waveform about the 0 volt line. A sustained tone with 2nd harmonic will have a "DC offset". You can demonstrate this easily by summing a pure sine with another at twice the frequency. See image. TD +-------------------------------------------------------------------+ |Filename: even harmonics.jpg | |Download: http://forums.slimdevices.com/attachment.php?attachmentid=1321| +-------------------------------------------------------------------+ -- tyler_durden ------------------------------------------------------------------------ tyler_durden's Profile: http://forums.slimdevices.com/member.php?userid=2701 View this thread: http://forums.slimdevices.com/showthread.php?t=23759 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
