Yes and no, the sub bass may be ruler flat, but the amplitude it can reach may not be very great so even if it can reproduce a very low frequency, it may be hard to hear. The LCD 2F is not making much audible at 20hz no matter what the measurements say, nor is the TH 600. I agree that the perception of deeper doesn't mean actually deeper frequencies are being produced well, there are always chamber reflections/refractions with closed headphones, and if what you mean is that the TH 600 sounds deeper, but it may be the extraneous effects of the chamber refractions making it sound artificially deep, then I agree that is possible if not probable. But we are talking about perception here and I do think that many people would hear the TH 600 as "going deeper". As well, I'm not sure that it doesn't go deeper in the real sense of the concept, and at a greater amplitude. I will need to have time to test which right now I lack due to other commitments. My comments, which I stand by, were in the context of people who are leaning toward bass-head preferences, which I do a little, and as does the OP I was responding to. So with that in mind, and acknowledging your correct point about perception and reality in a purely measurement sense potentially differing, I agree that it may be nothing more than perception of greater depth from the TH 600, but regardless, as it stands now, and it may change with more listening/testing, I perceive the TH 600 as being deeper sounding.