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Passive radiator questions

529 Views 2 Replies 3 Participants Last post by  noah katz
Cross-posted here as suggested.


Hello all.

First of all, this is going to be for a mobile subwoofer application, but decent mobile forums are few and far between, and my experience has been that there is A LOT of expertise on this forum, so....

I am installing a 10" sub in 0.85 ft^3 and am playing with what a passive radiator setup might look like.

I have read that a passive radiator (or two?) should be 1.5-2x the surface area of the active sub. First question: is this a hard and fast rule? I have seen many setups with one active sub and a single passive radiator of the same size.

I have been modelling various configurations in WinISD. The box I am using fits under the seat of a pickup truck, so there is not a ton of surface area for larger or numerous passive radiators.

I might be able to fit a single 12" PR. Can for sure fit a single 10". Could possibly fit two 8" PRs. Can definitely fit two 6.5" PRs.

Generally speaking, what sort of configuration would be a good starting point?

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not a great help but
this is a 10" UM and 4 x 6.5 PR's as figured out / recommended for me by a PE tech
for my Honda Odyssey van, running off 400 w. fit in the rear well . .
i don't recall the exact dimensions but you can see everything is very close together.
it's 1/2" BB, braced well inside and cute on the outside.
I have read that a passive radiator (or two?) should be 1.5-2x the surface area of the active sub.
What matters is Vd (volume displacement = PR cone surface area x excursion capability.

As an example, if the cones are the same size and you wanted 6 dB more output capability than the driver alone has, the PR would need to have twice the xmax as the driver.
1 - 3 of 3 Posts
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