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Anwar ( Team Pi
12-11-2008, 07:44 AM
I have heard from time and again that the smaller the box the bigger the spl.

I have tried that and I always go back to my very first box.

Is this true. Because I find that the car starts playing at a higher frequency and it starts to shake rattle and roll...

IDSkoT
12-11-2008, 07:46 AM
No.
In a sealed enclosure, the smaller it is (in proportion to nominal space) the more abuse it can take. (I.E. take more RMS power than rated for longer.)
In a vented enclosure, the less air space is more pressure that the woofer is working against. Larger enclosures will produce higher numbers, but risk over-exerting the driver, as well as over-working the coil.

DBBOOM
12-11-2008, 07:48 AM
You want Spl, you tune the box higher than normal, if thats what you mean. Usually a box is tuned somewhere in the 30-38Hz range, for music. In spl, its usually higher than that.

RAM_Designs
12-11-2008, 07:54 AM
Smaller boxes are used because you can throw more power at the sub(s) without it overexcurting. Try putting 3kw to an 18" SX in a 7ft^3 ported box and you'll see that it'll overexcurt very easily. Now put it in 2ft^3 and put that same 3kw to it, and voila, you're fine(generally speaking).

Obviously, this is a very simple way of explaining it.

Anwar ( Team Pi
12-11-2008, 08:13 AM
thanks guys.

i am currently in the stock one class. playing duel two with 2 5000z doing a 155.9db
i need help to get to the 157 mark.

this means changing my box...

IDSkoT
12-11-2008, 08:16 AM
Smaller boxes are used because you can throw more power at the sub(s) without it overexcurting. Try putting 3kw to an 18" SX in a 7ft^3 ported box and you'll see that it'll overexcurt very easily. Now put it in 2ft^3 and put that same 3kw to it, and voila, you're fine(generally speaking).

Obviously, this is a very simple way of explaining it.

I love words like 'generally.' Just to cover our *** in case ish goes bad.

Pyro_By_Nature
02-06-2009, 06:59 PM
No.
In a sealed enclosure, the smaller it is (in proportion to nominal space) the more abuse it can take. (I.E. take more RMS power than rated for longer.)
In a vented enclosure, the less air space is more pressure that the woofer is working against. Larger enclosures will produce higher numbers, but risk over-exerting the driver, as well as over-working the coil.

Please do not take about what you do not know, we're talking SPL here............ And besides, a sealed box won't increase thermal power handling, so it won't magically make the sub take it's RMS for "longer". You just have good cone control.

The loudest box I ever used in my street C set-up was a hair over 3 cubes for 2 15's ;) It all depends on the application.