Quote:
Originally Posted by
Head Injury 
What mid-bass issue is this? The 840 (or 940) don't have much of a mid-bass hump. Objectively that's a good thing, but combined with a fair sub-bass roll-off they're going to lack punch on poorly mastered albums.
Actually I found the 840 mid-bass definitely had a hump - quite noticeable too once I'd heard a few other cans. The 940 on the other hand extends really (scarily in fact) well - but I thought it was slightly light on the mid-bass.
OP - sibilance refers to the "sssss" sound you can sometimes get (especially with higher voices - often female) - usually found on cans that are 'treble happy'. I never found it with either the 840 or 940. The 940 have a lighter sounding bass than the 840 - mainly because of the absence of the mid-bass hump. The sub-bass is better on the 940's though - more defined and more present.
Are you sure you're not referring to bass distortion? That could be the bitrate your music is ripped to, or clipping.