uhh What does this do "passive radiator"

[PendulousThread 10+ year member]

http://www.woofersetc.com/index.cfm?fuseaction=product.display&product_id=2523

Ive never seen anything like this^^^

Click to read more...

 

[jmanpc 5,000+ posts]

it spreads radiation in your car and kills bacteria. may cause cancer, though.

 

[dumple 5,000+ posts]

it spreads radiation in your car and kills bacteria. may cause cancer, though.

hahahaha

i believe it acts as a port or something or it causes less stress on the subwoofer as it does the excursioning

 

[TreyE 10+ year member]

its passive because you can pass by it and think its a subwoofer... the radiator part is because what their purpose is it to cool your subs and when your sub start beating the "passive radiator" acts as a real radiator and cools your sub....its a scientific breakthrough pretty much

 

[squeak9798 5,000+ posts]

http://www.diysubwoofers.org/prd/

 

[bass_lover1 10+ year member]

its passive because you can pass by it and think its a subwoofer... the radiator part is because what their purpose is it to cool your subs and when your sub start beating the "passive radiator" acts as a real radiator and cools your sub....its a scientific breakthrough pretty much

I hope you aren't serious?

Anywho, a passive radiator is similar to a subwoofer except it has no motor structure, just the suspension, cone, basket, blah blah. It works similarly to a subwoofer except it receives no electrical signal of any sorts, but it uses the pressure that the subwoofer creates inside the box to resonate, a lot of companies will add mass to the structure to change the characteristics of the PR.

It's very similar to a port, but you can save space because the PR will usually be tuned to a specific resonant frequency and thus your box will comparatively be smaller, and give you similar output.

 

[twisztdauthorit 10+ year member]

its a speaker without a motor..

it is used with another speaker

When the sub woofer moves.. it causes the passive radiator to move with it which causes an increase in db's

it worthless by itself unless paired with another sub in the same box.

 

[TreyE 10+ year member]

I hope you aren't serious?


Anywho, a passive radiator is similar to a subwoofer except it has no motor structure, just the suspension, cone, basket, blah blah. It works similarly to a subwoofer except it receives no electrical signal of any sorts, but it uses the pressure that the subwoofer creates inside the box to resonate, a lot of companies will add mass to the structure to change the characteristics of the PR.

It's very similar to a port, but you can save space because the PR will usually be tuned to a specific resonant frequency and thus your box will comparatively be smaller, and give you similar output.

lol extreme joke..not even close to being serious

 

[bass_lover1 10+ year member]

lol extreme joke..not even close to being serious

lol ok, it's occasionally hard to pick up on sarcasm while reading text //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Where in tampa are you? I'm about 45 mins north of you in New Port Richey.

 

[Fi Car Audio 10+ year member]

Before the advent of all the cool programs that calc PRs, I used to approximate a PR design by using the SD of the cone and equating that to a cylindrical port. Given the box size, tuning, and the PR sqin you can calculate the length of the "port" (often obscene given the SD of a 12" PR going into a 1.5 cuft enclosure). From this port length and port area you can calculate the volume of air and therefore the mass of the air in the port. That mass is the theoretical mass your PR will need to tune the box to the frequency you have calculated... I say theoretical as you are assuming that the suspension of the PR is close to that of air (ultra floppy) when in reality it isnt. The floppier the PR, the closer this comes out right. To tweak just add mass.

But since we no longer communicate via smoke signals or the pony express, you simply plug in a couple of things into a program to get the same results... along with the graph and excursion levels of the PR at given frequencies and power.

Normally you use twice the volumetric displacement for the PR as for the driver itself. (2)12" PRs per 12" sub (with similar excursion levels) or usually you can get away with kicking the PR up to the next size (15" PR for a 12" sub).

PRs work great for home... and somewhat well for car applications, although the PRs need to be mounted horizontally (to the axis of movement) as they will sag heavily due to the moving mass and lack of suspension.

Thanks...

Scott

 

[00poop6x 10+ year member]

Before the advent of all the cool programs that calc PRs, I used to approximate a PR design by using the SD of the cone and equating that to a cylindrical port. Given the box size, tuning, and the PR sqin you can calculate the length of the "port" (often obscene given the SD of a 12" PR going into a 1.5 cuft enclosure). From this port length and port area you can calculate the volume of air and therefore the mass of the air in the port. That mass is the theoretical mass your PR will need to tune the box to the frequency you have calculated... I say theoretical as you are assuming that the suspension of the PR is close to that of air (ultra floppy) when in reality it isnt. The floppier the PR, the closer this comes out right. To tweak just add mass.
But since we no longer communicate via smoke signals or the pony express, you simply plug in a couple of things into a program to get the same results... along with the graph and excursion levels of the PR at given frequencies and power.

Normally you use twice the volumetric displacement for the PR as for the driver itself. (2)12" PRs per 12" sub (with similar excursion levels) or usually you can get away with kicking the PR up to the next size (15" PR for a 12" sub).

PRs work great for home... and somewhat well for car applications, although the PRs need to be mounted horizontally (to the axis of movement) as they will sag heavily due to the moving mass and lack of suspension.

Thanks...

Scott

You're welcome.

Guess it works great for me since my home is my car. Yay.

 

[TreyE 10+ year member]

lol ok, it's occasionally hard to pick up on sarcasm while reading text //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
Where in tampa are you? I'm about 45 mins north of you in New Port Richey.

south tampa...yea i know where you are ive driven to NPR a couple times

 

[Twistid 5,000+ posts]

so you make a box for 2 woofers, you put your woofer + the PR in ? what the air movement causes the PR to move making more air movement? making more deebeez?

how come we dont use like 10 of them on everybox we build then? downfalls?

 

[Railrocker 10+ year member]

They were used a lot in old school stuff when woofers lacked in excursion. Dont really know why they fell to the wayside,