Any fear of these being bass light is certainly unfounded. These cans really thump. Unfortunately my pair came with a nasty vibration in the right earpiece. Something inside the cup rattling or a blown driver (I doubt it's blown though, but that is sort of what it sounds like). I'll have to get a replacement.
Does it do it all the time or only with bass? A piece of hair finding its way to the the drivers and vibrating with certain low frequencies sounding like the driver is broke is a very common thing at least. Have had to that prob with these Q40 headphones 3 times in like a half year or a little less already, then again I use it with a ZO2 bass boost amp that strengthens bass quite a bit too so it raises the chances greatly for hearing vibrating piece of hair issue.
Also what's the bassiest headphone you've got experience with and how does Focal headphones compare like with those to get a better idea of the bass strength.
Edited by RPGWiZaRD - 3/12/12 at 6:33pm