On Mon, 2006-09-04 at 23:05 -0400, Josh Koffman wrote: > On 9/4/06, Jesse Lackey wrote: > > Yes most are in that range, 25-35 ohms. However some higher-end ones > > are much more - 300 to 600 ohms. Quite a different thing to drive these > > without clipping, you need +-15V or more. (AKG 242, for example, are > > 600R and used in studios). > > My understanding was that the higher impedance ones were meant to be > used in parallel so that the effective impedance was brought back down > to a lower value. Then again, I don't remember much of my training in > this area, so I don't really understand why the higher impedance ones > are subject to clipping with lower voltages? Clipping is one of those terms which is thrown around too much IMHO. There are TWO types of clipping in this case, clipping in the earphones (meaning you are trying to move the diaphragm more then it can physically go) and clipping of the amp. In the case of higher impedance headphones we are talking about clipping of the amp. The amp simply doesn't have enough voltage to drive the headphones at a "loud enough" value and ends up clipping. Obviously you CAN use higher impedance headphones, they just won't get as loud as "normal" impedance headphones before your "normal" amp starts clipping. TTYL -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist