How effective are passive radiators?

[corporalcripp]

Altec Boleros have 'em

My 890c Boleros have PRs(oh pardon,phase inverters!).Great punchy bass & they're efficient as well.Only thing is,they don't go very deep.-Bob

 

[Arkay]

ESS AMT 1bs and other ESS models also used PRs, and --despite the problems with crossing over effectively to the AMTs without a low-midrange (which they really needed), the PR works well with the bass. They did a stupid thing, though, and "tuned" the PRs by gluing wooden blocks to the back, instead of layering some material evenly across them. Had to introduce strange wave patterns and stresses in the PRs. :nono:

Interesting info here about Cannon speakers. I see the brand fairly regularly in the used-audio wholesale market here, and never realized they were made by ESS. Always assumed they were some store brand or other mid-fi brand. Maybe I'll pay more attention to them in the future.

 

[tarior]

Only Speakerlab i have heard was Tators Model 7 (I think) .

That's tarior!

Polk used PRs extensively, and most all that I have heard were very nice sounding speakers.

 

[rickr15]

do you have pics of those? i'm looking for info on some spkrs i had (used) in the mid 80s. i think i remember ESS. they look alot like these cannons on this thread. except mine were equipped more like yours:scratch2:. XOs looked like a small city. my spkrs had a tough looking tweeter with a metal grill. 2 5 inch, i think, mids. a 12" woofer and a 12" PR. the Lpad was off to the right. these were very well-built spkrs. the mids had heavy tubes isolating them. the box itself had a baffle inside. i had them in my basement. they really vibrated the concrete floor! anyway if that rings a bell and you can send some pics, COOL! sorry for the derail, btw

Per your request. These have the tubes on the mids that also act as cab braces. Tweet has a Panasonic #EAS -9KH05S,the mids are open back Polydax. All the drivers actually have aluminum trim rings but I yet to install them in these pics. Also not installed is the 4" riser/isolator for the bottoms. hope this helps.

 

[max-ac]

Per your request. These have the tubes on the mids that also act as cab braces. Tweet has a Panasonic #EAS -9KH05S,the mids are open back Polydax. All the drivers actually have aluminum trim rings but I yet to install them in these pics. Also not installed is the 4" riser/isolator for the bottoms. hope this helps.

that' them! it's like seeing an old friend! THANKS!!!

 

[Chazzer]

"How effective are passive radiators?":scratch2: Well passively speaking, they can be effective and effectively speaking, they can be passive!

 

[Big Tuna]

Could these be the ones? I googled looking for pics of mine but the ones below are the Cannon TLS 1232T which are tower versions of mine.

Mine look like the top part with just the one 12" woofer with inverted surround.

Hi terra, sorry for my late reply. Yes, they are the 1232T's. I like them alot and I just recently made it to Tahoe and I restored them for my Mom. I knew after 33 years, they would be rotted, and in need of new foams. She loves them now and won't give them up easily.

PS-i just posted a new thread with pics of them while I fixed them up. They sound really great now, and I played some CD's with my DVL-909 player I brought from Texas. For 33 years they never so much as moved an inch and were never played with anything but cassettes and the tuner. they sound stunning with CD audio input. :yes:

 

[vannman77]

Could these be the ones? I googled looking for pics of mine but the ones below are the Cannon TLS 1232T which are tower versions of mine.

Mine look like the top part with just the one 12" woofer with inverted surround.

nice set i have same towers and the mini towers bought in germany in 1979 thtas exactly what the canon tls looks like i have replace woofer and passive radiator and they still rock

 

[shrinkboy]

We need to find a pacifist to answer that one.

i can't believe i said that

 

[Copa1934]

A properly designed speaker using passive radiators is quite capable of producing extremely deep, clean and natural bass. In fact, good speakers using PR's will measure less bass distortion than ported designs. Some tips for getting the best from them would include a high current amp and speaker distance to the rear wall. The closer they are, the more bass they produce, but too close and it'll get muddy. The better designs fire forward.

I would like to flip around Paul C.'s comment, if I may, and say that ports are a poor substitute for a good PR designed speaker.

My RTR's are just that. Best of all they deliver adequate bass at lower listening levels, to me a bonus. Another nice thing, depending on design, is the "drivers" are situated closer to ear level and usually the speakers have smaller foot prints. So a number of advantages besides sound.