Theophilus Punoval
The Queen says it's OK...
This question has probably been asked and answered before, but here goes anyway: What are the advantages/disadvantages of passive radiators?
Passive Radiators
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gslikker
Super Member
YES, I put a bid on a pair of Kef Calinda once, and the guy on the phone became angry when I suggested the bigger driver on the bottom is a passive one and not a woofer.
I should not have told him, because his price was okay but he told me even if I would pay asking price he did not want to sell it to me anymore, he was so much pissed off....
Putterman
Super Member
Porting is more often used because it is less expensive to use, a piece of plastic vs. a speaker without a magnet. It is also takes up less space than having an 'extra' woofer which ideally, should be larger than the active woofer.
Theophilus Punoval
The Queen says it's OK...
Great!! What's "FS"?
DavidF
Active Member
Think of the PR as a tube port substitute. Depending upon the woofer parameters the vent needed to tune down to a desired frequency can result in a very long port tube. The PR can most often tune lower using mass rather than larger port dimensions. So the designer could use the PR when the port dimensions for a desired tuning are too large or impractical for the enclosure dimensions. The there is spurious noise containment as mentioned. Also, open vents can unload at low frequencies with the risk of over-drive failure and added warranty expense. Disadvantages are added cost for the part and fitting same. Finally, placing the component in smaller enclosures can be a problem.
JWinTN
Well-Known Member
The lower-priced GoldenEar towers use "quadratic planar infrasonic passive radiators."
wmgwizard's video explains it all.
wmgwizard
Addicted Member
I'm not sure that a port is actually a substitute for a PR.
I was under the understanding that a port is used to tune the resonant frequency of the enclosure and that tuning would allow for additional output down to the tuning frequency. Once the signal is below the tuned frequency the driver can become "unloaded" and the port becomes a liability. Ported enclosures do not afford the same control of the woofer that a sealed enclosure does, sometimes being described as sounding "slow" or lacking impact.
I believe the PR offers many of the benefits of a ported enclosure without some of its limitations. The PR allows for increased low frequency output due to the increased surface area exciting the air, without the potential of becoming unloaded and loosing control of the driver and since the enclosure remains sealed there is no real sacrifice of "impact" or speed.
I am not an engineer and could be completely off base here and welcome any information that might enlighten me to the errors of my misconceptions.
Theophilus Punoval
The Queen says it's OK...
"The lower-priced GoldenEar towers use quadratic planar infrasonic passive radiators."
My bilateral ocular sensors immediately suffered an effusion of hemoglobin while scanning that phrase.
My bilateral ocular sensors immediately suffered an effusion of hemoglobin while scanning that phrase.
damacman
Resident Psycho
That is a very clever demonstration in that video. There are many ways to use passive radiators and they are an excellent tool. Sometimes, a given port can be physically impossible to fit into a given enclosure given the desired tuning frequency and the enclosures size or shape - this is just one of many examples of where a PR can be better suited.
Look at the JBL Olympus. One has to question why JBL chose PRs instead of a traditional vent to tune the enclosures. BITD, we used to build a lot of PR enclosures for automotive sound systems. The enclosure size didn't have to be spot on and the PRs always delivered a very full sound. We purchased woofer cones and dust caps from the local speaker repair shop and preferred those over flat radiators.
Look at the JBL Olympus. One has to question why JBL chose PRs instead of a traditional vent to tune the enclosures. BITD, we used to build a lot of PR enclosures for automotive sound systems. The enclosure size didn't have to be spot on and the PRs always delivered a very full sound. We purchased woofer cones and dust caps from the local speaker repair shop and preferred those over flat radiators.
C.A.P
Well-Known Member
They tend to be tighter than ports and not quite as a Sealed enclosure but dont suffer from the loss as a sealed.. Now Throw a curve into the mi as Vandersteen uses a Active passive coupled driver ! Its not a sub that is powered but rather a ACTIVE PASSIVE design..It only plays 500hz and lower but is usless without the 8 inch running in phase with it.. I know I tried when replacing them .. When together its amazingly deep and tight bass... Not sure how but it gives damn good bass
dc270
Now Off the Reservation
I have built passives and love them- it is just more than throwing in an oversized drone driver however. It need to be "tuned" to be accurate. Once tuned properly it is an excellent product! For more tuning info please note below.
http://www.mh-audio.nl/PassiveRadiator.asp
DC
http://www.mh-audio.nl/PassiveRadiator.asp
DC
JWinTN
Well-Known Member
Well, everyone knows that infrasonic radiators, especially when you throw in some quadratic planar-ing, are the only radiators worth having.
And I was mistaken—all the Triton towers have passive radiators.
Theophilus Punoval
The Queen says it's OK...
"And I was mistaken—all the Triton towers have passive radiators."
Carramba
Carramba
