Sub Specs

Hey guys, I forget what i'm supposed to look for when it comes to the technical stuff on a sub, like f's, and q's, and all that. I found the spec sheet on the subs I am using right now. Tell me what u think:

Power (watts peak): 1200

Nom Impedance (ohm) 8

Voice Coil: 2.5" KSV

Magnet Structure: 2x90oz

Fs: 23.2

Qms: 4.92

Qes: 0.84

Qts: 0.72

SPL: 85

vas: 4.908

Now, I know these specs are probably horrible, but can u tell me for future references what i want next time?  Thanks alot.

Not necessarily.  The Fs defines how low the speaker can play compared to another speaker in a given alignment.  But a vehicle has a natural boosting of low frequencies.  So using a subwoofer with an extremely low Fs (like would be found in a home audio sub) will give you too much low end.  Also, a low Fs must come at the cost of something else.  If you want a lot of low end extention, you will have a sub that either requires a larger enclosure or is less efficient.  From what it looks above, they gave up efficiency (Spl is a little low).

Another thing you don't necessarily want is that high of a Qts.  It gets that high Q from such a weak motor, which can be seen from the high Qes.  Because of this high Q, the sub would only work well in a sealed enclosure.  And you will never get an alignment lower than the Qts, so you will never get a .707 alignment (maximally flat) or lower.

Vas gives you an idea of the enclosure size needed.  The one above is very large for a 10" sub, a little large for a 12" sub, and not too bad for a 15" sub. 

I would guess from the parameters you are showing us a cheap 15" home audio sub.  Am I right?

Steven Kephart

Adire Audio