is this box design crap? 2 sa12's

[bobk83]

I built a box today that is 34 wide 15" high and 18" deep. the port is 2.75" wide 13.5" high and 15.25 deep and bends to another 11" for around 26 in length. the box is for 2 12" sundown sa 12's and its powered by a audiopipe 15001d. as far as I can tell its tuned to around 31 hz and is just shy of 12 sq inches per foot. the box doesn't sound bad but I just expected it to hit lower and a bit louder. am I expecting too much from these subs or is the box I made just crap?

[volkswagginvr6]

are the subs chambers separated at all? you could possibly have some cancellation problems if not. i could be wrong though.

[bobk83]

No the sub's share the same chamber. I think I'm going to send a request for a box design again. I tried pwk before when I wanted a design for a 4th order and never heard back. I gave up on the bandpass idea. Maybe with a properly designed box I would be happier

[volkswagginvr6]

good luck bud

[bdog]

how many cubes?

[Joe X]

I get from your data 3.16 cubes @30 Hz 37.125 square inches of port, you have low port area, low net volume and low tuning, not to say is total crap, is just rather inefficient, if you didn't have more space then you may need to live with it as a 4th bandpass would need much more space.

[Omega5002]

The low net volume is what's killing your low end, from personal experience, low tuning plus small box equals bad. In order to get output from the low end of low tuning, you need a big box, because the bigger the box, the lower the resonating frequency(which is also called f3), when you have a lower resonating frequency, then your low end output will increase.

[bdog]

I think u could make a 3cf enclosure for those that will be super loud. You might not have the best range but will be loud. My suggestion is that if u can't go bigger try bringing up the tuning to 35 and opening up the port maybe to even as much as 17 cf per cube

[bobk83]

thanks for getting back to me.originally I wanted to keep access to the spare tire, I made a floor out of 3/4" wood to hold the weight of the box and added hinges so I could lift it to get to the spare. the box can be no deeper than 18" that way, which makes it tough getting a decent size box in. I might scrap that idea and make a bigger box. if I was to make a box that's 34wide 16.5 tall and about 20-22 deep with a port tuned to 33 with 52.5 total port area and 12.77 per foot would that be an improvement? after watching videos on her of these subs I cant help but think the boxes ive made are holding them back .if anyone has a design id be glad to pay for it.

[bobk83]

i hate second guessing if it could sound better in another box. I got lucky with the one bandpass I built for a single re se x 12. that was pretty damn loud and played deep. that one 12 played lower and louder than these two in my opinion but only sounded good on certain songs.since that box I haven't had much luck making the pair sound the way id like with the space I was trying to use.