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View Full Version : passive radiator use?



req
12-30-2004, 08:57 AM
i was just wondering when you would actually use a passive radiator. ive seen them mostly at adires website, and to me, it looks like a woofer with no magnet\voicecoil. just a suspension\basket that feeds off the pressure from a working woofer in the same enclosure.

im not too sure how or when these are practical, and what kind of benefits come from an application with a passive radiator.

does anyone have any *useful* information on these things? id like to know a little more about them, and if they are useful in a certain application (home theatre maybe?)

thanks guys. about time we started talking about car audio again. stupid lounge forum :readytog:


//edit
heres a link to the adire page i was talking about-

http://www.adireaudio.com/TextPages/PRPageFrameText.htm

squeak9798
12-30-2004, 09:38 AM
You are correct; PR's are basically motorless subs. Just a cone, basket and suspension.

PR is basically similar to porting; only instead of using a port, you select your tuning frequency by the mass of the PR.


READ MORE HERE (http://www.diysubwoofers.org/prd/)

And here is some more from partsexpress:

Passive Radiator: A moveable piston often constructed like a woofer without a motor structure, which is used to tune a box to a certain frequency. The frequency at which a passive radiator (of a fixed diameter and compliance) is tuned is controlled by the moving mass of the diaphragm. Some benefits of a passive radiator enclosure are the elimination of extremely long ports, the non-existence of port noise, and higher frequencies will not leak out through the port.

req
12-30-2004, 09:46 AM
hm. so id have to get dual 15" PR's to work out my tempest eh? would it increase the output since its adding twice the cone area, ie,+6db?

squeak9798
12-30-2004, 09:48 AM
hm. so id have to get dual 15" PR's to work out my tempest eh? would it increase the output since its adding twice the cone area, ie,+6db?


You would get the same boost in output that a regular ported box would give you.

req
12-30-2004, 09:55 AM
ok cool.

i was just looking at other cool options for a car. maybe ill try a 10" woofer with a 12~15" PR someday. it looks fun.