help with bandpass in 2001 focus trunk...please

[ktraughb 10+ year member]

it is a trunk focus. my most recent box was a pretty run of the mill 4.25 cu ft box, tuned right around 40 Hz. it did fairly well for spl, and still had some musical quality. what i am thinking of doing now is a type of bandpass enclosure. i understand sq is at a loss for most bandpasses (not all) but i also understand that if done correctly they can be much more efficient than a simple slot ported enclosure.

first off, has anyone attempted to build a bandpass in a similar trunk, and second off was it a fourth or sixth order? i simply dont think ill have the room for a sixth order, but some general plans i have made for a fourth order would work. overall usable external space is about 8 cubic feet. the one i have designed is about 6 total after displacement.

does anyone have any pointers whatsoever on designing a bandpass as far as chamber sizes (not specific obviously but a generalization of comparison from sealed to ported chamber). the subs will most likely be a pair of p3s, type rs, or some ma audio hks.

i dont have the t/s handy for any of these so im simply looking for some general rules as of right now. any help is appreciated ahead of time. also, i am not opposed to porting into the cab through seat opening, and i have already cut a ten inch port opening through my rear deck for an older box. so it is usable as well.

Click to read more...

 

[slapperz 10+ year member]

Block of writing... hurts my eyes to read...

 

[ktraughb 10+ year member]

are you saying you want me to go back and edit this into shorter paragraphs? if that hurts your eyes youve surely never read a good book.

 

[Canadian_Dude 10+ year member]

Bandpass boxes are tricky to get right. They are also limited in bandwidth, but are more efficient. Unless you are going for high output and don't care much about sound quality I would steer away from them. There are a few programs to help you design a box, such as Unibox(free, needs microsoft office), WinISD(free, buggy, complicated), and Eminence speaker Designer/BassBox Pro(not free, but my favorite).

 

[ktraughb 10+ year member]

yeah i have win isd alpha, my only downfall is that on the subs i currently have i do not have the t/s paramaters, and i dont think theres really a way to get them.

 

[galacticmonkey 5,000+ posts]

I know for a fact that the Type R 12s jam in a 4th order thats 2 cubes sealed, 2.5 ported, 50in^ of port 17" long. Build that, you wont be disappointed.

 

[MisterGrubbs 5,000+ posts]

What woofers?

 

[Canadian_Dude 10+ year member]

I know for a fact that the Type R 12s jam in a 4th order thats 2 cubes sealed, 2.5 ported, 50in^ of port 17" long. Build that, you wont be disappointed.

I just modeled this in Win ISD and this is what it looks like.

 

[ktraughb 10+ year member]

I know for a fact that the Type R 12s jam in a 4th order thats 2 cubes sealed, 2.5 ported, 50in^ of port 17" long. Build that, you wont be disappointed.

is this for a pair or the specs per sub?