Passive Radiator

[XaznKewLguyX 10+ year member]

I am totally lost on this concept. What exactly is it and what does it do? I just ordered a tc10 OEM and it says for ported boxes:

Ported:

0.5-0.6 cubic feet with a single 10" or 12" PR

Can someone explain it to me or give me a link i've searched and found nothin.

Click to read more...

 

[Max_Power 10+ year member]

http://tcsounds.com/tcvmp.htm

should tell you something....

 

[hoss 5,000+ posts]

in a nutshell, if you dont understand it, its not something you need to concern yourself with... not to sound like an *** about it, but it really isnt anything that you should be considering or contemplating.

but to explain what it is, it basically acts as a secondary radiating surface (cone) . it acts kind of like a port in an enclosure. your primary woofer causes the passive radiator to oscillate, and it acts sort of like a second woofer. its not powered, and it is moved passively by the pressure waves of your actively powered woofer. it is literally a passive radiating surface.

the effect of this, is similar to a ported enclosure. the only difference between using a PR and a ported enclosure is that with a PR you get a narrower response curve boost, and the bottom end roll off is much greater than that of a ported enclosure.

 

[Duke 10+ year member]

No port noise.//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[hoss 5,000+ posts]

No port noise.//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

no port noise in a properly built ported enclosure either //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Duke 10+ year member]

no port noise in a properly built ported enclosure either //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

I expected someone to say that.//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif I'd like to try a high end passive out though sometime.

 

[XaznKewLguyX 10+ year member]

ahhh i see i guess its kinda making sense now. so the PR is the sub itself pretty much? I thought it was something else.. //content.invisioncic.com/y282845/emoticons/blackeye.gif.66a1670f5aaf7f406e783a63e3387dc5.gif

 

[Prowler573 5,000+ posts]

ahhh i see i guess its kinda making sense now. so the PR is the sub itself pretty much? I thought it was something else.. //content.invisioncic.com/y282845/emoticons/blackeye.gif.66a1670f5aaf7f406e783a63e3387dc5.gif

A PR has no motor, no VCs, etc.

Just a basket, a spider, and the cone iirc...

 

[bdawson72 5,000+ posts]

ahhh i see i guess its kinda making sense now. so the PR is the sub itself pretty much? I thought it was something else.. //content.invisioncic.com/y282845/emoticons/blackeye.gif.66a1670f5aaf7f406e783a63e3387dc5.gif

No its like another cone...a completely seperate cone,surround,etc....it doesnt have a motor or voicecoils

 

[Prowler573 5,000+ posts]

A PR has no motor, no VCs, etc.
Just a basket, a spider, and the cone iirc...

No its like another cone...a completely seperate cone,surround,etc....it doesnt have a motor or voicecoils

We were on the same page with that one, bdawson.

Posted the same thing at the same minute according to the timestamps //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[Rich B 5,000+ posts]

No port noise.//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

No unloading the cone below the tuned resonance either.

 

[XaznKewLguyX 10+ year member]

ahhh i think i understand now.. cant wait till mine gets here !

thanks for the help everyone!//content.invisioncic.com/y282845/emoticons/thumbsupwink.gif.129404938effda6ad9cca39e7f4b58a3.gif

 

[Immacomputer 10+ year member]

ahhh i see i guess its kinda making sense now. so the PR is the sub itself pretty much? I thought it was something else.. //content.invisioncic.com/y282845/emoticons/blackeye.gif.66a1670f5aaf7f406e783a63e3387dc5.gif

The passive radiator is more similar to the port in a ported enclosure than it is to the sub. The port on an enclosure is a mass of air that gets set into resonance and moves back and forth just like the passive radiator does. Around tuning, this is where the majority of the output is coming from, not the sub.

 

[XaznKewLguyX 10+ year member]

The passive radiator is more similar to the port in a ported enclosure than it is to the sub. The port on an enclosure is a mass of air that gets set into resonance and moves back and forth just like the passive radiator does. Around tuning, this is where the majority of the output is coming from, not the sub.

i assume this is why they require such a small ported enclosure?

 

[Immacomputer 10+ year member]

i assume this is why they require such a small ported enclosure?

What? The sub requires a small enclosure, which is why they recommend a PR. You would need a good amount of port area and that would cause the port length to get very long, which would take up a ton of space, to get a nice low tuning. To save all that effort, you can use a PR and save a bunch of space. To lower the tuning on a PR, you just add mass to the system since the radiating area is staying the same. That's the same thing you're doing when you add port length -- you're adding mass while keeping the radiating area the same.