posted
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.
-------------------- Kenneth- TEAM DAILY Louisville, KY Posts: 1328 | From: Floyds Knobs, IN | Registered: Mar 2005
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posted
Well, I do know that subs forward and port towards the side works awesome if you don't go the BP route. I would say your best bet would be to make a very large outer shell and build a few sealed/ported enclosures to put in there and test out the ported chamber by working out the port area.
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better yet. based off what you have told me, what do you think about this rough variation of that type of an enclosure? basically ported to the side, subs firing forward, but surrounded by a much larger box. basically a box that would fill the trunk and seal it off to face forward. heres a very rough sketch in paint:
-------------------- Kenneth- TEAM DAILY Louisville, KY Posts: 1328 | From: Floyds Knobs, IN | Registered: Mar 2005
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quote:Originally posted by kenneth: yeah that is a thought that i had since i probably wouldnt need to change the sealed dimensions at all with the ported side varying.
this design worked great. i figured id go ahead and try it out since it was simple to do with one sheet of wood. ive got right at about 4.5 cubes after all displacement, tuned at 40 Hz, 72 sq inches of port. its nasty. i havent metered it yet, but i know its at least louder to the ear than the same spec size box with subs and port facing the rear. this is with the same battery and amp as well. i was extremely impressed at how efficient this design is. also, i faced the port to the driver side, with about 7 inches of clearance before the side trunk wall. with seats up or down its ridiculously loud. thanks for the info.
-------------------- Kenneth- TEAM DAILY Louisville, KY Posts: 1328 | From: Floyds Knobs, IN | Registered: Mar 2005
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posted
I don't know how it would work. The only way to find out is to build it I would try that enclosure and one with the sub and port facing forward. I do know that some loud trunk cars had an outer "shell" and the subs used tubes for their enclosure. People would cut the tube length down and moved the tubes in the shell to where they stopped gaining.
posted
well this box you suggested the first time is working great. i will meter it on a termlab before the weekend is over. im not sure what it will do on a mic but i love it for daily driving. moves some serious air in comparison to my old rear facing box. i did tune it a little higher as well.
-------------------- Kenneth- TEAM DAILY Louisville, KY Posts: 1328 | From: Floyds Knobs, IN | Registered: Mar 2005
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Yeah, it's a pretty cool design. That's what I had in my old car about 3ish years ago. I wish I could have tried it with a single large port instead of four 4" ones.
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i used a slot port. didnt feel like trying to mess with any pvc right now. still sounds ridiculous. ill meter it this weekend. ill post pics of what i did. unfortunately its so big that its terribly hard to get in and out or else id try to turn it around to the rear and have port facing passenger side.
-------------------- Kenneth- TEAM DAILY Louisville, KY Posts: 1328 | From: Floyds Knobs, IN | Registered: Mar 2005
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