Hopefully this has more importance than just resell price. I've got a 2xxx serial one and the bass on it is quite impressive, I'd say one of the most pleasing types of low end without the typical box sound due to earpads. The punch is what gets me, you wound't expect the low end to hit as hard as it does with more than adequate grunt. LCD-3 has nothing on them but LCD-4 has better low end. The only drawback is rolloff, under 60hz tends to be quiet. So if the bass is impressive then it's bass heavy? That said I heard my pair on a Vitus SS-101 directly on the speaker taps and honestly I couldn't say it was better than my tube 2A3 SET or OTL amps. Still a fantastic experience and I would rather listen to it than the Wilson Benesch speakers we were auditioning.