subwoofer question


hi everyone, i have a chance to buy 2 m&k mx-150thx(mark I) subs for $900 shipped.
first off is this a good deal or am i over paying.
next, because these subs are old (10-15 years), can they compete with the new subs which use better technology.
i only use my system for home theater.
my room is 14x12.
will these subs be great for my room or should i get one really great "USED" sub like a jl fathom, or velodyne dd series, svs, etc.

thanks so much
nineballg
Post removed 
Bob is correct. My previous posts were my attempt to explain why there may be a common idea that a large driver mean larges inertia, means "slow" bass and why that idea may not hold water. I covered the momentum side. Bob closed the loop by explaining that the extra mass of a larger driver may be accellerated just as quickly as the lower mass of a smaller driver, provided that the force applied to it (the motor assembly) is also proportionately larger.

Bottom line: IMHO driver size and "speed" are not related. I am 100% sure that others will disagree.

Marty
Bob, Marty,

thanks for your answers!

We may be down to hair splitting now but if we take two similar subs like a JL Audio Fathom F113 and F112, these are very similar, do you guys still think the F113 ar faster?
Off my memmory of comparing these two at audition the sound quality was virtually indistinguishable to my ear. Both sounded very, very good (set up 2 channel with Maggies at a local hi-fi shop). I'm pretty confident that most listeners would find (provided that both are operated within their respective limits and without HT style effects info to distinguish performance below 20hz.) that they sound very much alike. The bigger sub will (presumably) play louder without distortion.

Marty

In the price range that you are looking at, I would go with a small driver sub that doesn't necessarily go really low. I think you will end up rolling it off at 30 hz anyway to take the room out of the equation. I would much much rather have a to little bass than to much bass.