Building a sub box have some questions?

[lonniejr]

first question is how do i build a bandpass box?
i have a Power Acoustik Mofo-10, and want to build a band pass box for it, any help would be awesome, or if you can give me exact measurements would be even cooler :) also do i need equal volume in the front and the back or what?
second question is about volume and port.
when you build a sub box i know you need a certain volume for particular sub, question is do i build the box at required volume then add the port or add the volume of the port to the neccessary volume for the sub? like sub needs 1.75cu.ft. do i add the port volume to it, or add the port into the box itself, without making it any larger?

thanks everyone really appreciate the help

[Mikz86TA]

Bandpass is complex. There are quite a few styles. Its much like building a ported box but with an additional sealed chamber or ported chamber on the front side of the sub as well.
Volume in front and back are not the same and depending if the front and back are ported or just the one side is ported will make a difference on the airspace.
Throw in port volume subtracted, and figuring out the port tuned fequency. Very complex to get right.

If ur doing a simple ported box...you have your dimensions and figure out the internal air space to that. Loading the sub takes up some airspace tho a small amount. Then your port weather round or slot, will also take up some of that space as well. Thus making your original internal air space volume less than before.
Figuring out the port volume is the same as box volume and you can subtract that number from your box volume number

[lonniejr]

ok thanks i've built quite a few boxes, went to build another today and huh i forgot some things lol, i do remember how to figure out port frequency and volume etc. just couldn't remember some things, so if i was to build a bandpass, more or less what i do is.. build a ported box, put the sub in then attach and sealed or ported box to the front, at according volume specifications for the sub? correct. lol or more or less anyway lol.