here is a box i drew up for a friend. it will fit behind the seat of an older dodge truck.

it is about 1.6cf with all displacements included. the ports are not drawn in there but he will be useing (3) 2" ports 10" long. should tune around 31-32 hz.
its 15" high 6" wide at the top 10" wide at the bottom and 36.5" long.
the middel piece is located 12.15" from the end of the box. and all the angles are 75 degrees









^^ that the middle and end parts parts.

alot of the measuremts are stupid numbers like 8.3", 4.70 etc. i just convert to mm and go from there

i didnt put alot of effort into drawing this box becase if we need measurements or something we can just look at my computer. but for those that want to use it injoy

 

That program defintely makes some nice looking diagrams. I'd caution you though about the 2" ports. I tried that once with a Coustic 10" about 15 years ago making a ported bandpass. Got a whole lotta port noise and a that was about it. Unless you're using multiple in place of a larger diameter port but you aren't. I'd do whatever you can to fit in 3" ports.

 

intresting. "port noise"is typical of a poorly designed bandpass boxes. especially a 4th order.

i have a friend who bought one of those prefab 4th order band pass boxes loaded with 2 12's. it had 4 areo port and still had alot of port noise.

but i wonder how port velocity is affected when we compare an abc to a regular ported box. you would think an abc would have less velocity due to haveing "more port".so i think you could actually get away with less port area. its bad i dont have the time to do real world testing

 

Prefab and bandpass are not exactly two words I'd use in the same sentance to refer to a box that performs properly

I suppose you may have a point about an ABC box effectively having double the port area since both chambers have ports firing to the cabin. Nonetheless, the 2" may still make noise. I made an ABC for a single 8" using 2" ports and you could hear it chuffing occasionally.

 

prefab = but when you have a properly designed bandpasses the results can be very pleasing in both sq and spl.

as for the port noise i guess its all going to come down to how much power is used and when dealing with rond ports its very easy to get a bigger piece if pipe

 

I don't want to bust yer ***** but if you don't have the time to test your designs then how do you know how well they work?? Math and design programs are handy but a builder picks up a lot of rules of thumb and guidlines by building the design and testing it.

I also caution building an ABC for a 10 with 2" vents. It will definitely make noise.