i have a sheet and a half of MDF in my garage and i need to do something w/ it. i'm thinking bout doing an ABC box here pretty soon, but i've never messed w/ em before. does anyone have any info one how to build them?
i usually only mess w/ vented and sealed boxes, but i wanna give ABCs a try...just because, you know. ;)
go to sounddomain.com and go to forum and then freq. asked questoins and tutorials. there should be a section on building abc boxes. they are pretty big boxes though.
an abc box is kind of hard to explain, but it is a sq box that are usually very large. it consists of ported box that has a seperate chamber that has another port. usually the ports are tubed. there is a connecter tube that connects the chamber with the sub and the empty chamber. i dont know how much sense that makes put hope it helps and if some part is unclearified then im sure that someone will fill you in.
An abc box is a regular ported box that has been divided internaly to give you two chambers. One chamber being twice as big as the other. Then decide what tuning frequency to have and calculate the port length as if you where using two ports. Make three ports this length and put one port in each chamber to the outside world and the 3rd port joining the two chambers internaly.
So for example....if you have a 3cuft box you split it so you have one chamber 1cuft and one chamber 2cuft. Assuming a tuning of 35hz using a 4" port. Calculate as if you where using two 4" ports in 3cuft. This gives a length of 15.5". Make three 4"x15.5" ports. Sub and one port in bigger chamber one port in smaller chamber and 3rd port joining the big and small chamber.
There are other variations like sub in big chamber with one port joining to small chamber and one port from small chamber to outside or sub and port in big chamber with port to join to small chamber which otherwise sealed. I don't know how to calculate volumes or port lengths foe these variations.
The first example is universal and works with all normally calculated ported box volumes. If you Google for abc, dual ported, aperiodic bi-chamber or D. Weems(the inventor?) then you'll get a stack of info.
?? glass, john, anyone?