View Full Version : Mini 6th Order Bandpass Enclosure Design

05-19-2009, 06:48 PM
A little something I've been working on for the past week. I'm thankful to be done, alot of calculations, my head hurts lol.

Anyways, onto the goods. I designed a 6th order parallel tuned bandpass enclosure for a little 8" sub I had ripped out of a home theater powered sub enclosure. It sounded like ***, and the way I see it, if this 6th order doesn't come out right (which theres a 50/50 chance it will), then it will sound like *** anyways, so I'm no worse off. :laugh:

Obviously there are no calculators or magic formulas for 6th order boxes for the most part, so I figure I'll never get it if I never try, so here's my attempt :D

Rear Chamber
1.4 cubic feet @ 35 Hz
4" diameter round port - 16 3/4" long

Front Chamber
0.9 cubic feet @ 67 Hz
4" diameter round port - 5 1/2" long

I know the volumes are a tad large for a single 8", but this gives me a tad more room for a slightly larger port area, and it leaves it open for me to add another 8" loaded in an isobaric fasion (cone to cone) and a few dowel supports for the end of the ports.

Anyways here's the finalized design sketched up. Hopefully I can start building it in the next week or so. It's about 2 feet by 2 feet @ 11" tall, so hopefully it can slide under my bed and stay nice and hidden while it pounds the house :D

This is also my first 6th order design by the way, so any comments are welcome, criticism included.


Also, one last question, I was contemplating doing the top of it in plexiglass just because that would look baller. What thickness is generally needed to be strong enough for a small build like this, and how much does that stuff cost approximately?

05-19-2009, 07:55 PM
if you add another 8 iso style it will sound like crap m8

compund loading will make the speaker act as one wiht 1/2 the vas and double the BTL factor so you would ahve to cut the size of the front and rear chamber buy say 50% but keep the port the same length which ussaly is hard becasue you wnat the port the same but you loose the space to put the port in the box

so if you think you can just compound load subs wishout changing anything your totaly wrong and shouldnt even build a box

if you meant something diff sorry been at work all day :)

any box that is compound iso'd wiht subs that has a port is 99% of the time a waste becasue the port endsup being so long you will make a box in the end that is the size or the box ported for 2 subs reg even tho oyu are 50% less total volume to begin with

i was doing a box for 4 re8's ok ported

box is ussaly say 2cf for 4 subs i got away wiht .5cf+ displcemtn but the 8.5in x 2in port i wanted to use was 58in long, lol so the box was about 2cf after i was done


05-19-2009, 09:25 PM
I think we might be thinking about two different things. Only thing the way I'm talking about would change would be taking up like an extra 0.03 cu ft. in the sealed chamber and making sub movement more linear and increase the peak ever so slightly according to WinISD, but obviously those don't replicate real world designs.

As far as the box you're talking about for 4 8's, look at the box in my sig, very similar, it's for 4 sundown E8's. 0.6 cubic feet per sub @ 28 Hz, so the port is pretty long, hence the double folded port.

05-20-2009, 08:23 AM
d that looks great let me know how it does i've got a jbl gto8 new in box i don't kno what to do with so hit meup w/results
and i have plenty of plexi and you could use 1/2"plexi plenty strong for such a small build

05-20-2009, 08:33 AM
Honda + Subs = Rattles :(

05-20-2009, 08:50 AM
Honda + Subs = Rattles :(
random much?:confused::confused::confused:

05-20-2009, 04:55 PM
Yeah, I'll deff. let you know how it turns out. It might be a little longer than expected though, I've gotten quite a few requests for designs and builds in the past few days, so I might be a bit busier than expected :laugh:

I was hoping for 80inches to post his $0.02, so far, he's the only one I know of that has produced solid 6th order designs and boxes. Even if it's criticism, I would like to know what I could change as I'm interested in making a 6th order box, the complexity makes it super awesome :D

05-23-2009, 05:20 AM
so far ur on the right track...looks good


05-23-2009, 08:23 AM
well there's the $.02 you were looking for :veryhapp:now hurry up ad build it so if it works well I can bite our design and copy all your hard work as my own lol:D:D:D good luck w/it

05-23-2009, 03:58 PM
well there's the $.02 you were looking for :veryhapp:now hurry up ad build it so if it works well I can bite our design and copy all your hard work as my own lol:D:D:D good luck w/it

Well, currently this is on hold, 95% chance I'm going to be doing a build for a member here on CA who just so happens to be a local in NW Indiana (and I thought I was the only one in this hick town with subs :() So we'll see how long that takes. This coming week is my last full week of school, the week after I've got only like 3 days and then I'm done so that's when I'll probably do this build, hoping to get that one guy's done before then. Problem is, and this is no joke... I'm scheduled to go in to the oral surgeon and get my wisdom teeth removed, THE DAY AFTER I GET OUT OF SCHOOL. How ****ing lame is that?!?! So I'm going to be totally out of it that weekend and hopped up on Vicoten. So for my safety and yours, I will not be building boxes, operating power tools or saws :laugh:

Hopefully I can get this stuff on track though, I'm dieing to know what this little 8 will sound like in a 6th order.

05-23-2009, 10:06 PM
well I might just build it first if I can get my fat azz off the x-box gl w/teeth