Designing Box

[lamsv]

In the past, upon buying a new subwoofer I have always just built boxes recommended in the owner's manual. This time around I decided to try my hand and crunching the numbers myself. The driver in question is a JL Audio 10W3V3-4 which will be going into the trunk of my Q45.

I downloaded the free version of winisd and set out to design a box. Based on the parameters of the speaker, winisd showed that a ported box would work best. Unfortunately, it is a rather large box. Just over 2 cubic feet tuned to 26hz.

Next, I tried to see how it would perform in a sealed box. Winisd suggested a box just under 1 cubic feet. Problem is, the F3 is 46hz, which seems rather high.

This leaves me with 2 questions. First, concerning the ported box: Can I fudge the volume? For instance, can I design a 1 cubic foot box tuned to what ever frequency I want? Will the speaker then in turn perform in said box?

Second, with a F3 of 46 hz, I am scared the sealed box won't perform to my liking. A friend, though, said that in a car, cabin gain will bump my low end response, shifting the F3 to around 25hz. He himself says he shoots for an F3 of 45 hz for a car situation. Is this true?

I have spent the last couple weeks surfing this website and have found a WEALTH of great information.Thanks for any help you can lend me!

-Seth

 

[chlorofille]

Hi Seth, the cabin with contribute quite a significant low bass gain. For fast, musical bass I suggest you go for a 1 cubic feet closed enclosure. That size models perfectly too in Bass Box Pro. (enclosure simulation)

 

[lamsv]

I am leaning towards the sealed enclosure, if only because of its smaller size (Q45, for a big car, does not have a big trunk).

Another question. I have a couple options for amps to power the sub. Both amps have a bass boost centered at 45hz. Will this hurt or help the low end response... or just create a bump in the frequency curve that is not good for the overall sound?

 

[chris661]

Nah, leave bass boost switched off. If you can up the size of the cabinet a little (stuffing would help), you can get a shallower roll-off, which will complement the cabin gain better.

When you have it built, then play around with eq and things.

 

[lamsv]

I have a couple 1lb bags of Acousta-Stuf that I will be using. I think I will be going through with the design at this point. From all I've read and heard, this design should work well in my car.

Thanks for the input!