Does this box look okay?

[toylocost]

I'm gonna build this box for a friend and he is buying a couple P3 12s for it. Dual 4ohms.

Anyways I just wanted to make sure this design looks good to you guys. I get lost in the math and wonder if I did everything right?

Here are the specs for the speakers from Rockford.

http://www.rockfordfosgate.com/scripts/rig...ated=1083014016

Here is what I came up with... (for 2 speakers)

Volume 5.47ft^3 (net including port)

Port 31.25in^2 and 6.5in deep

Trying to get about 37hz out of it?

This looks right to me but I'm kinda tired right now. Anybody care to confirm or deny my design?

[Torres]

just an fyi...the net air space is 5.47 NOT including port volume, like you mentioned above. the net airspace in the calc is the actual airspace the subs will see, minus wood, sub/bracing, and port displacement. just to keep in mind

and you're going to need about double the port area for that box. as it stands, you need around 66-88 sq inches of port, where you have 31.25 sq inches. that's 5.7 sq inches per cubic foot. way way low. 12-16 sq inches per foot is a general rule of thumb you should stick around.

[toylocost]

Hey thanks expo. Does this look any better?

[jesterjames]

Hey thanks expo. Does this look any better?

yea

if it were me id drop down to 34hz tuned, make sure you double up on the front face (1.5" face)

[Torres]

3 hz wont make a very audible difference. if one at all. and if that is a slot port, then that will bring his tuning down to about 34.56 hz, which is right in that ballpark regardless

[Mac58]

Looks good I have made a few boxes for RF P3's (they were my first pair of subs, gave em to my gf and she's bumping them ) Anyway I think youd be surprised at what 3 hz would do. I made a box tuned around 37 and the p3 hit hard but it lost a lot of SQ to me. I made another box (which my gf is using now) and tuned it to 34, sounds MUCH better as far as SQ and it SLAMS. If your friend WANTS sq AND spl 33, OR 34 IS THE NUMBER TO GO WITH IMO just a suggestion

[wL<3bass]

I've tried a good bit of tuning variations....and I have to say I like higher tuning around 36-40hz with alot of port area (14-18sqin per cube).....I've tried lower tuning 30-32hz (12-14sqin per cube) and mid tuning at 33-35hz with (12-16sqin per cube) and I have to say my favorite is the higher tuning still plays low (like mega-C&S low) but can still play in the upper 50hz range without sounding sloppy and uncontrolled.