Hi blokes, i own 2 p.audio TM-12 subwoofers but i was wondering what i should do to get the best performance out of either one or 2.

Well what i was really thinking was im going to make a big box for my vs calais. I was thinking because these are powerful subs do you think if i made a huge box and put one sub and tuned the ports perfect to it would i get more bass out of that single sub or with the same sized box put 2 subs and try and cram it all in? Most likely gonna run it off some sort of mono block 1500watts plus.

So yeah tell me what you think i got a link of the sub aswell
http://www.usspeaker.com/paudio%20tm-12-1.htm

I haven't got much background information or specs on them don't know why but i stumbled across em and got 2 for free so im laughin...

cheers brendon

They don't actually need huge enclosures, they'll both work pretty well in ~80L tuned to 35hz. 2x 10.4cm (common pvc pipe size) ports 44cm long.

One option you could consider is an isobaric enclosure, which will allow you to get the same performance in an enclosure 1/2 the size

At twice the cost, twice the power, and requires twice as many woofers....

...and with no audiable improvement to the sound quality.

with double the moving mass it plays lower and i think power handling is increased, not 100% one the last one?

I was under the impression that in an isobaric situation the second woofer compensates only for the reduction in the original enclosure size and therefore you don't get the gains (audiably) that you would if you were using the two subs in a 'normal' loading situation (both being used).

The power required is halved due to the fact that you are now using two woofers rather than just one though you could look at this the other way around and say that the handling of the system has increased! However this way of loading will either be 3dB down in output or it will require twice the power to acheive the same volume as a single speaker in a larger enclosure.

It decreases the distortion levels, and linearity is better.

u can quite easily fit a 120L+ box in a car liek that. without suffering total boot loss. there is a 120L box in a VP i did and it only lost maybe half?

I stand corrected!
Is it audiable?

It depends on the driver used, the crappier the driver is the bigger the improvement is from my experience, very high quality drivers don't show much improvement since they are already very linear.


The main improvement I've seen is an almost complete reduction in suck in/suck out that can occur in vented enclosures, it's typically caused by a non-symetrical magnetic field in the voice coil gap.