View Full Version : Need help!! Will this hurt my sub?

12-04-2006, 11:27 AM
I built a box for my Type R 10 the other day. I had the volume at right over 1 cubic feet. I built the box a little big, but when building the box, we built the box a tad bit bigger. Alpine says a ported box should be built between .8 - 1.25 cubic feet. This box is 1.97 cubic feet. I haven't calculated the room the sub takes up, or the 3" pvc port at 7.25 inches at 32 hz.

Will having that much extra room damage the sub? Should i build another box or will this one work?


12-04-2006, 11:33 AM
should be fine

12-04-2006, 12:15 PM
1.97 - 0.03 - 0.15 = 1.819 ft tuned @ ~33hz

It'll be fine, though You're a little low on port area:box vol. for my tastes.

12-04-2006, 05:17 PM
There will be port noise.

12-04-2006, 06:28 PM
Will the port noise be so bad that it warrants building a completely different box?

12-04-2006, 06:54 PM
You need more port.

4" aero, 12" long will put You at 1.7 ft @ 36hz

Roughly double the area.

You want (ideally) 10 in^2 of port per ft^3. This figure, is up for debate.

12-04-2006, 06:58 PM
So go 4" instead of 3"? Should i still figure the port length on 1.97 @ 35 hz? I've also thought about going to 33 hz, but I'm not sure.

12-04-2006, 06:59 PM
As far as 4", I just bought the 3" pvc pipe. I'd rather use it if at all possible. I may just have to use the extra mdf and build another box.

12-04-2006, 07:02 PM
You can run (2) 3" ports 18" long.

This'll get You 1.65 ft @ 33hz, with 8.5 in^2 of port.

12-04-2006, 07:03 PM
So port placement really doesn't matter then? It's an L shaped box...

Can you place both ports on the same side? The box is only 24 inches long in the back...

Not sure exactly how to place the ports...

12-04-2006, 07:09 PM
preferrably on the same face as the woofer.

You can use 90* elbows as needed.

12-04-2006, 07:15 PM
You can run (2) 3" ports 18" long.

This'll get You 1.65 ft @ 33hz, with 8.5 in^2 of port.

14 in^2 of port area, not 8.5.

pwnt by pat
12-04-2006, 07:33 PM
build the box biger, use two sections of your 3" pvc, and double the port length.