Where s the bass?

My guess is your speaker placement is in conflict with your room. Your sweet spot may be in a node of negitive bass frequency. Please tell us your room size and where your speakers are in the room, side wall dimensions and rear wall dimensions. Also tell us where your sweet spot is located (dimensions)

May I second chas' and Jadem6's posts above. Had similar experience and found this to be A)less other frequencies, B) related to 1st reflection damping on side walls & ceiling (speakers in conflict with room..). The info JD suggests will help.
Cheers!

The two most likely explanations, which have been suggested:
1. Ability of low frequency signals to pass through materials, thereby making it seem louder outside the regular listening area. (Example: the car audio "boom and thud" subwoofer systems that can be heard a block away.)
2. Wave interference or cancellation in your room. If this is happening, the low frequency signals at your listening spot are actually less that they could be. You might want to invest in having an A/V pro come to your house and do an RTA analysis.

Also keep in mind that Lower Freqs. have a longer wavelength, that allows them to travel farther away from your sweetspot.

IMHO the explanation of this phenomena (that incidentally
I was thinking about for few days now ) folowing the same
observation as yours is the following:
as Limabean observes, the lower frequencies have a much longer wave lengh that the other frequencies and in order
to reach a maximum has to travel accordingly that distance.
I understood that a full range trasducer with full bass
extension down to 20HZ ( not necessarly from recorded music,
but from an artificially generated recording/sampler as
the Stereophile Test Disc 2 or 3...)will reach it's peak
at about 40 linear feet traveling from the transducer.
I have a pair of speakers claiming such 20Hz reproduction
( Apogee Scintilla ) and indeed the sound in the 17' long
auditioning room doesn't reach the same bottom as the same
sound travelling through the open door another 25' or so,
right at the end of a corridor, were everythin vibrates and
shakes in burst of energy. I might be wrong, but that's my
explanation to what I've observed.