So when the specifications of a sub say the min/max amount of cubic feet of airspace for a box, is that with or without the sub?

Also, when you guys decide to build a box, how do you do it? Conventional geometry or a computer program? I've tried programs Blaubox and WinISD and found them so incredibly difficult I'm left asking here...

Thanks guys, your help is really appreciated

 

Pretty sure its net volume, subtracting the volume the sub takes up inside the box.

For simple boxes, I use BoxyCAD... its an excel spreadsheet and makes it easy to build rectangular boxes.
http://www.audiodiycentral.com/resou...xyCad-v1-1.xls

 

Yup, usually with the sub.

I just draw a 3d picture, write down the biggest dimensions I can use, substract the wood thickness, and figure up cu ft, then subtract the subs volume.

 

would you recommend a down-firing setup or a up-firing setup?

 

I usually make as big a box as I can with the little space I have to work with, do the geometry(paper+calculator), then enter that volume into ISD, let it give me a curve, that way I know what to expect the sound to be like...

 

I always think that the sub should fire in the direction that has the least impedence, i.e. nothing in the way that may hit the sub. So, if you put a sub under a seat, it should fire down. As far as building your own box, it's pretty cheap to purchase a box and it saves you time.

 

up vs down firing, that's a good question, i've seen both setups but haven't really seen much debate or rationale on here. Most of the pre-fabbed ones are down firing, I think. Down firing would probably do a better job of muffling any stray mid-bass output that isn't rolled off by your crossover.

mine is down firing, i'm thinking about putting mastic (similar to Dynamat) under the area of the floor where the sub fires.