Opaqueice - have you tried any other frequencies...could you be hearing an intermodulation effect...it's odd that you notice a change in pitch, implying some harmonic interaction... Have you tried 60hz, 100 & 120? Your signal could be "beating" in or out of phase with another low-level sound somewhere (eg mains hum) - you might only hear the effect because of the harmonics being generated - the hum might otherwise be so low level as to be inaudible...
It would be visble on a scope though... I think I posted elsewhere that the sound made when a cone only moves inwards in MOST speakers is going to be slightly different from the sound when it only moves outward...because of the effect of the cabinet and the air trapped inside behind the cone...this will mostly affect the bass (not much air i smoving at higher frequencies) and is one reason why isobarik (sic) units are nice... -- Phil Leigh ------------------------------------------------------------------------ Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 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