No, you had it right the first time: 1 box of 35 liters per pair of drivers. So two 35 liter boxes for 4 drivers....
Attached is an isobaric I made for a pair of 12 inchers and a plate amp.
But if I had 4 woofers I would also explore force cancellation by mounting two woofers across from each other in opposition. But that does unfortunately mean the full 2x35 = 70 liters for two drivers, and two of those (L and R). More bass though, and with one woofer run 'backward' you get good harmonics cancelation, or something.
But if I had 4 woofers I would also explore force cancellation by mounting two woofers across from each other in opposition. But that does unfortunately mean the full 2x35 = 70 liters for two drivers, and two of those (L and R). More bass though, and with one woofer run 'backward' you get good harmonics cancelation, or something.
Attachments
I'm afraid not.
By doubling the motor force and moving mass, isobaric loading means you'll get the same response in a cabinet half the size of that of a single driver.
ie, if one driver wants 35L, an isobaric pair will want 17.5L. Two isobaric pairs (4 drivers total) will want 35L again.
You can play around with WinISD or Hornresp and see that this is the case.
Chris
I didn't find any info of use on-line, so with no driver specs, please define 'optimum', i.e. is it the size you want or what the manufacturer recommends for one driver? Sealed, vented [BR], band-pass [BP]? If BP is it 4th, 6th order?
GM
Years ago, I built a box with 4 12" drivers, one on each side of the box. Put a top on it, and draped fabric over the whole thing. WAF very good. This was long enough ago, I had no clue about "optimum size", and after building it, I swept it, and measured resonant frequency and "Q". Modified the xover to match, It did a great job for me. Since replaced with 4 10" separate boxes, built into decorative columns, though the "table" is still in use, just not connected anymore.
No reason you can't follow that direction if you want.
No reason you can't follow that direction if you want.
i just figured i gave another example of why bourbon and typing dont mix, i probably did anyway.
This discussion is hilarious. With 4 8" drivers I'd be thinking about Geddes' multi-sub approach (provided I had the channels of amplification, not that you'd need much).
Just sprinkle these 8" in larger-than-"optimal" boxes (~20-25 liters? I rarely see recommended alignments close to qtc = 0.7 for automotive drivers) around the room. 25 liter cube with 18mm plywood sides comes out to 330mm per side (more or less).
Just sprinkle these 8" in larger-than-"optimal" boxes (~20-25 liters? I rarely see recommended alignments close to qtc = 0.7 for automotive drivers) around the room. 25 liter cube with 18mm plywood sides comes out to 330mm per side (more or less).
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