Musical accuracy in subwoofers


I'm hoping some members who are more musically & technically knowledgeable can answer my questions about subs. While sub shopping, web research and sales people make referrence to subs with accurate timbre. The Linn & REL lines were reported to be more accurate than Sunfires in this respect. After playing my sub at a 45-48 hz. crossover without the main speakers, listening leaves me wondering how timbre ( at this low a crossover point) can be an attribute of a sub when most aspects of timbre are a product of higher frequencies. It seems that pitch accuracy, lack of bloat & "overhang," freedom from cabinet resonance, and the ability to tune crossover, volume, & phase accurately are paramount. But timbre?
photon46
I've only been to about 1000 professional live classical performances and counting. Aside from degrees in physics and EE so I know some math, I also completed a major in musicology and played french horn in a student orchestra. I have also have measured a fair amount of live and reproduced music. I stand by my example, 3%-10% harmonic distortion will significantly shift the reproduction of timbre in the lower bass octaves.
while low-frequency extension is obviously important, i agree that thd is a critical spec for subwoofers. perhaps that's why the vmps subs, when used w/a quality outboard electronic x-over, are such over-achievers at their price-point. vmps' published distortion specs are, if not the lowest in the industry, right up there w/whoever is. most subwoofer mfr's don't even publish their distortion specs.

doug s.

10% distortion from a sub playing at a sound pressure level of only 70db is ridiculously high, assuming the sub is engineered for 30hz performance (alot aren't sadly enough, then again they aren't true subs), which shouldn't be a problem for the $1k+ subs like REL, Velodyne, VMPS, etc. Now then again, maybe I don't know, I haven't seen all their specs. But, I can only see those type of massive acoustic anomalies plsl mentions kicking in at somewhere towards the subs maximum output, not normal listening. This is all assuming we are talking "real" subwoofers since Photon mentions REL, Linn, and sunfire, along with others in the price range like the Velodyne's (which claim very low distortion values) not the $449 msrp Jamo's.
fyi, vmps' most expensive sub, w/options, lists for <$800, which includes shipping - not an insignificant amount, considering it weighs ~140 lbs & is *big*. dealers *will* discount, as well. specs for this sub are 17hz-250hz, w/0.5%thd at 92db/1w/1m; 2.5%thd @ >115db. at this price, ewe can get two, a good outboard x-over (i like marchand), & a quality used amp (or two), & it will still cost less than *one* quality powered sub like a velodyne hgs18 ($3k), or a rel stentor ($4k). w/two subs, soundstage is improved, room integration is easier, and, for given spl's, thd is even less.

ymmv... doug s.

ps - no, i *don't* work for vmps - yust a satisfied customer! ;~)