Air Space Question?

[Grimster74]

Getting prepared to start building the sub enclosure for my car. After taking measure measurements for the size of the SEALED enclosure this is what I've come up with. By the way, I'll be using dual MM2124's wired as a 2 ohm load which according to Polk suggest an air space of 0.88 cubic foot per sealed enclosure. After measuring the space I have to work with the measurements are as follows: 35" wide, 15" high and I can go as deep as I want but I prefer to keep it under 9". After calculating the internal volume I've come up with roughly (per enclosure) 13" high x 16" wide x 7.5 deep / 1728 = 0.90 cubic foot. The sub enclosure will roughly be a shaped as a square filled with poly fill. My question is, should I make the enclosure's internal volume larger and if I did, would I benefit anything from it. I had planned on going by the recommended Polk specs but I just wasn't sure if anyone could tell me what a larger internal volume would do. Thanks for your help in advance.

Rob

[Grimster74]

Okay, I've been doing some research today and it never even crossed my mind to factor in the driver displacement. I've looked everywhere on Polks website and for the life of me can't find this info anywhere for the MM2124's. Anybody know what the driver displacement is for this subwoofer? Thanks again.

Rob

[McLoki]

With external dimentions of 13x16x7.5 and working with 3/4" material I come up with 0.57899 cubic ft. (as you mentioned - that is not taking into account driver displacement either) Seems a bit small for a 12" sub to me, but that is not based on anything scientific....

BTW - if you have not seen it - This is a great page (http://www.the12volt.com/caraudio/boxcalcs.asp) to help figure out box volumes and port sizes (you have to scroll down to see most of the information)....

Michael

[MacLeod]

This is the best tool Ive every found for coming up with the best box size and shape.

http://www.bcae1.com/spboxnew2.htm

[Grimster74]

With external dimentions of 13x16x7.5 and working with 3/4" material I come up with 0.57899 cubic ft. (as you mentioned - that is not taking into account driver displacement either) Seems a bit small for a 12" sub to me, but that is not based on anything scientific....

BTW - if you have not seen it - This is a great page (http://www.the12volt.com/caraudio/boxcalcs.asp) to help figure out box volumes and port sizes (you have to scroll down to see most of the information)....

Michael

Those dimensions are the internal dimensions, not the external.