need help with abc enclousure for pair octane r12d

[sprung]

i have a pair of octane r12d and would like help with abc box design .ive read about them and like the versitility of the duel tuning of the low and high end bass .i have now a pair of 10 jl wo in a 5th order and it plays the low end pretty decent but of course i want more. i mainly listen. to techno stuff like bass nector and old school bass music .so figured a pair of 12 would do it.its all going into a 2012 challenger and is being powered by a m44 on rear channel paralelled bridged for 1ohm load with bass knob should be great sounding with the proper bo

[kg1961]

first off don't run a m44 at 1ohm bridged it will fry.

[Bfowler]

that^ even 2ohms without fans is pushing it.


other than that....sorry, but i've never played with bandpass boxes. you might have to ask some of the people over at diyma

[Kirghiz]

A 4th order bandpass is an easy enough enclosure. The back chamber needs to be the same as the sealed enclosure, and the front chamber needs to be about 1.5 times the size of the rear chamber. From there you tune your port to somewhere in the 50's or so and let it rock.

Also, to echo what everyone else is saying, you need a new amp.

[THUMP-LUMP]

Actually, bandpass enclosures are the hardest to design properly. Here is a screen shot of two different subs chosen at random and modeled in a single reflex (4th order) enclosure. If you look at the volume for the front and rear chambers for each one, you can see that they vary wildly from the 1 to 1.5 ratio suggested. They are very sensitive to tuning and I would suggest that you actually measure the T/S parameters of the speakers you intend to use and not rely on a manufactures spec sheet. They can be off considerably.

My experience with bandpass enclosures is that they sound dead, musically. Sure, if done right, they will produce a higher SPL than a sealed or ported enclosure, provided they will even work well in a bandpass enclosure. Not all subs will work well. From sealed to ported to single bandpass (4th order) to dual bandpass (6th order), with each step you gain Db at the expense of quality and they become progressively harder to get tuned right.

[zztunnell]

I agree with thump. Ive built 4 different bandpass boxes over the years. 3 4th order and 1 6th.To do it correctly you really need to test the TS parameters of the actual speaker used and meticuously measure every cubic inch of everything in your calculations. In my 6th order box even 1.5 cubic inches made a very noticable difference in the graph I got. Im not familiar with a 5th order. Is there such a thing? IDK.

[THUMP-LUMP]

My guess about the reference to a 5th order enclosure is that it is a 4th order with a 6db passive xover which would add one more "order" to make it a "5th order". Adding an "order" in this way does nothing but cloud the issue. While a xover is required for a bandpass enclosure to eliminate harmonics that will pass (and they sound reallllly bad), they should not be included in the enclosure "order". More precisely, enclosure design should be referred to as "alignment" and not "order" but, many use both as interchangeable words. If I were to build a "4th order" enclosure and add a 12db LR low pass xover, would that mean I have a "6th order" enclosure? Not hardly.

IMHO, subwoofer enclosures should be referred to as types of alignments, IE: Infinite Baffle, Sealed, Ported, Single Bandpass, Dual Bandpass, Transmission Line, Folded Horn, and they just get weirder from there. Crossover components, be they passive or active, should not be included.

[zztunnell]

Makes since when you spell it out. I guess Im just a victim of habit after hearing it that way for so many years.