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passive radiator vs. ported

Old 07-06-2010, 08:44 AM
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passive radiator vs. ported

I have exactly 1.5 cubic feet total internal volume available for an enclosure. My choices are to either do a ported 12" with a net volume of 1.31 ft^3 after sub and port (round 4"x7.5", as a slot port will take too much volume...port noise is worrying me as well) displacement. This will give me a tune of 42 hz.....or....I can use a passive radiator and essentially tune where i want, but will cost 80.00 more. What's the major drawback to the passive vs. ported system except cost?
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Old 07-06-2010, 09:56 PM
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passive radiator gives u the spl of ported but with the sound of a sealed box.. and u can tune the passive using the weights that they supply.. easier to tune anyway... if its available to u with the sub ur running id go for it
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Old 07-09-2010, 10:15 PM
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How many passive radiator systems do you see on the market compared to vented? If the results outweighed the cost and effort, you would see more, but they don't.
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Old 07-10-2010, 04:52 AM
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home theater seems to have more of them
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Old 07-10-2010, 10:40 AM
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Yep - there someone has spent the time to make a static enclosure, tuned the PR, and then cranked out copy after copy. Not so well suited to car audio. Vent chuff is a bigger issue in home audio as well.
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Old 07-10-2010, 12:06 PM
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PR has a steeper roll off. I don't know if the sub can become unloaded, can it?
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Old 07-10-2010, 10:04 PM
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A steeper rolloff? Please explain how.

Both the sub and PR can unload.
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Old 07-11-2010, 05:23 PM
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My bad I was thinking bandpass.

PR is -18db per octave.

Sealed -12, ported -24.
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Old 07-12-2010, 02:55 PM
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Bandpass is 4th order as well, -24db/octave, at least on the top end. If it is a sealed bandpass, the bottom end is still -12db/octave.

How does a PR achieve 3rd order rolloff? Link to that info?
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