i saw a calyx (d'n'b) and teebee video once where they used a sub and used that to check whether the sub of their tunes matched 'REFERENCE' tunes with bass/mixdown they loved. plus touching the speakers or the 'cones (?)' in the speakers may be useful as well, in order to feel if it thumps enuff. i'd deffo say REFERENCING. i once heard that in loads a techno records the bass is below 320 Hz mainly --> that made melook at tracks in a freuency analyzer and it really seemed to slope down very very often at that freq. when i tried it myself i noticed i could make the bass as loud and fat as i wanted, if i then put a lp filter to make this massive bass only play beyond say 320 hz aprox it would be mahosive like the bass of so many records and not clouding or muddying up all the rest of the track. won't be nay help to you mate, though, i reckon. i'd say do a search on bass/ sub whatever over at dogs on acid the grid. that's the bass place, imo!!