Sub Box Question...... - NJFBOA - Home of New Jersey's Camaros and Firebirds

NJSPEEDER · 09-12-2006, 08:47 PM

don't worry, i haven't lost my mind and started putting weight into the car. a friend asked me to help him make a box for his car and i need some tips before i get to work on it.

when building a box how important is the recomended air volume? the basic design he has written down makes a pair of 1.1 cuft areas and he said his subs call for a 1cuft volume. is this going to negatively effect the sound quality?

the system he wants also calls for a single 12 in a band pass style exclosure. the volume is easy since this chamber will be a cube, but i am having trouble finding info on how much surface area to remove for the air opening. he would like to stay away from a tube opening and have the air opening at the bottom of the front of the enclosure so it is more subtle and clean lookin. is there a formula or chart for how big an opening is needed?

and the last question for now, there will be some portions of the box made from fiberglass. woudl two layers of woven matte be enough to stay together and still sound good?

thanks guys. i am sure i will have a lot more questions when i have to build the amp rack for him

V · 09-13-2006, 12:10 AM

1.1CUft seems VERY small for a bandpass enclosure with a 12" sub. My 12 mules call for .75-1 Cuft for sealed, the smallest of all the types of boxes, and most subs require 1-1.5 for sealed and around 3 for bandpass. Have him chekc that to be sure. but .1 cuft isnt THAT big of a deal IMO. BTW, foam filling is used usually to make a sub think a box is bigger(i think thats what it does, lol)

qwikz28 · 09-13-2006, 01:01 AM

a little bigger or smaller isnt a big deal. too big or too small is a problem. and tell him to forget about bandpass and get his tuning fork out and makind a nice ported box

r0nin89 · 09-13-2006, 08:44 AM

I've got two 12" Boston rallys in my enclosure. Granted they are old they still sound good ina box thats only the top half of my thirdgens well. I could never here the difference in enclosed and ported and alot of air displacement area and not alot... Idk maybe my subs would sound better with a bigger box.