MHarrisEP

I have two Type R 12's, dual 4ohm coils on each.

I'm trying to design a box for them, but I need some information first.

The program I'm using requires me to fill out this form, and I don't know what half of it means, so I couldn't even look it up if I tried, haha.

Could someone help me out? A capture of the form is attatched.

jalat

iTrader: (6)

4 Cubic feet @ 34hz

Top - 33"x20.5"
Bottom - 33"x20.5"
Front - 29.25"x13.5"
Back - 33"x13.5"
L Side - 19.75"x13.5"
R Side - 19"x13.5"
Port 1 - 16"x13.5"

MHarrisEP

Okay, thanks. That's the most efficient box for 2 Type R's?

If it's not too much trouble, I'm interested in knowing how you come up with that?

I know how Sketchup works, haha, but I mean the proportions and such, what's the formula?

Way2slo

iTrader: (1)

Thats probably before woofer displacement so tuning will change. Youll want to take that into consideration.

jalat

iTrader: (6)

no, this is after woofer displacement.

i use WinISD to create my subwoofer enclosures. then i use the rockford fosgate enclosure calculator to determine the airspace and dimensions needed to make the enclosure. the above blueprint has been used in a system before and worked great off 800rms. it gets down low really well and matains good balance up the hz range

MHarrisEP

Okay, cool. Thanks a lot. Do you happen to have the woofer info for WinISD though? That's what I'm trying to use, but it doesn't have a preset for Type R's, so I need to put all that information in manually.

Satellite^Guy

Trust jalat's design, he's the one who gave me the box design specs for my 10" Type-R, and it sounds awesome.
I can only imagine what two 12's would sound like, with the right box.

S^G

mustaine4prez

Jalat knows his . Trust his box design. he uses all the same programs I do and I haven't seen one mistake in any of his designs yet. keep up the good work Jalat.

also you know you can get all those specs on the alpine site right?
Alpine Electronics of America, Inc. - SWR-1242D

MHarrisEP

Oh, I trust him. I'm in the process of building the box now. :] I appreciate sharing the design a lot! I'll let everyone know how it sounds when it's all done!

Satellite^Guy

Actually, I just remembered that my 10" Type-R came with a booklet that had the specs for all the Type-R's.
If you still want to play with WinISD, the specs are as follows, for the SWR-1242D:

Qts: 0.47
Vas: 45L
Fs: 29Hz
Re: 3.7+3.7ohm
Le: 3.71mH @ 1kHz / 1.67mH @ 20kHz
Xmax: 18.2mm (.0182m)
Z: ?
Qms: 7.89
Qes: 0.50
SPL: 85dB
Pe: ?
BL: ?
Diam: .275m (mounting diam?)
Sd: 480cm^2

I couldn't find some of the specs you needed, and some may need converting...

S^G