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
Also if you buy used,listen to real deep sounds only while checking it out.This may reveal a damaged voice coil from over driving.It will sound like something rattling or jingling inside it.You may have to put your ear close to it.It should take only a few minutes to hear this.
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Not a lot of stereo information below 40Hz but wont two subs in stereo be preferable to two in mono?
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Perrew,

No.
(Provided that the subs are crossed below app. 90hz.)

IME. YMMV.

Marty