To whatever extent it might be argued or imagined to do so, a conventional vent does the same....
How effective are passive radiators?
- Thread starter d-ray657
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dnewma04
The Healer
To whatever extent it might be argued or imagined to do so, a conventional vent does the same....
Of course. Luckily, it appears that wasn't the intent of the designer to make that analogy. But had it been, I suppose you could construe the added output of the port could make it sound like it had more cone area but it would never be the approach i'd take to describing the behavior.
FredC
Well-Known Member
The config on the woofs is 8" + 12" + 12" PR. I think his objective word is "effective" area, not actual area.
These are mine:
If I had to pick one pair of speakers out of all the speakers I've ever owned, these would be it.
AlleyKat
Super Member
Thanks for the info:thmbsp: I think I more or less understand the principles behind the passive radiators. However, this raises another question for me with regard to my Vandersteen 2C's. They use an 8" woofer combined with a 10" Acoustic Coupler (10" critically damped long-cone; 1 1/2" four layer voice coil with ventilated aluminum former). "The 10" rear-mounted acoustic coupler, together with the 8" forward-firing woofer helps to correct for "real world" conditions such as box loss, thermodynamic loss, and active/passive transfer non-linearities." 2C manual As I got lost after the forward-firing woofer part of the statement, could someone help me to understand how this works compared to a passive radiator? It appears to be another active driver, but is it?:scratch2:
rickr15
Super Member
I have a set of "Targa by ESS" that look prety similar to the pictured Canons except they have dual cone mids and a panasonic dome tweeter. Refoamed the woofs and PR's and so far to lazy to put em together and see how they sound.
Yes, it is another active driver, but the upper extension is completely limited by the big mass of MDF in the centre of the cone (which ultimately causes spider sag, but it can be corrected). I would presume that this not only greatly increases control of the frequencies the driver is producing, but also would speed up the timing a great deal. Certainly works for me with my 2Cs!
max-ac
Active Member
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
FredC
Well-Known Member
We need to find a pacifist to answer that one.
The whole bit about degraded transient response, is realistically, only about passive radiators with high resonant frequencies for their weight (ie, stiff suspensions). This is because the "spring force" of the passive starts to modify the transfer function (making it in effect, a fifth-order function as opposed to a fourth-order for a ported box). Making the suspension very soft, puts that 5th part of the function so far away (i.e., at a much lower frequency, as in two octaves lower or so) from the dominant part (the normal reflex-enclosure fourth-order response), that it pretty much has negligible effect, from a transient standpoint.
I've used passive radiators with soft suspensions (ie, self-resonance in the 4-5 Hz range, for box-tunings in the 20 Hz-or-so range), and found that oftentimes, the perceived transient response was actually BETTER than the same-tuned vented box, due to a lack of "port noise" (i.e., sounds from the rear of the woofer bouncing about the inside of the cabinet and making their way out of the vent).
The best-sounding bass system I've ever encountered, was a design (I'm currently working on a speaker using this) using TC Sounds woofers and passive radiators... two 10" woofers, with three 10" passive radiators per cabinet (one cabinet per channel). Bass is deadly quick and precise with pretty-much inaudible distortion, with extension down to 16 Hz and enough output capacity to make the windows, literally, visibly bow in and out with pipe-organ pedal tones.
Regards,
Gordon.
I've used passive radiators with soft suspensions (ie, self-resonance in the 4-5 Hz range, for box-tunings in the 20 Hz-or-so range), and found that oftentimes, the perceived transient response was actually BETTER than the same-tuned vented box, due to a lack of "port noise" (i.e., sounds from the rear of the woofer bouncing about the inside of the cabinet and making their way out of the vent).
The best-sounding bass system I've ever encountered, was a design (I'm currently working on a speaker using this) using TC Sounds woofers and passive radiators... two 10" woofers, with three 10" passive radiators per cabinet (one cabinet per channel). Bass is deadly quick and precise with pretty-much inaudible distortion, with extension down to 16 Hz and enough output capacity to make the windows, literally, visibly bow in and out with pipe-organ pedal tones.
Regards,
Gordon.
After several minutes of AC/DC at maximum volume, bass and treble settings simultaneously, many effective radiators become pretty darn passive... as in permanently passive (until they're reconed, or something like that)...
Regards,
Gordon.
Paul C
Super Member
Back around 1980 Speakerlab used what they called an "Active Hybrid Radiator" in several designs, the Delta 1 Hybrid Type Five, and Delta 1 Hybrid Type Four. It was not quite a PR, it was actually a woofer.
The Type Five consisted of a leaf tweeter, 2" Dome upper mid, 6.5" poly cone mid, 10" woofer, and 12" active radiator. The Type Four consisted of a leaf tweeter, 4" mid (a Polydax unit), 8" poly cone woofer, and 10" active radiator. Both were in tower type cabinets.
They also had their Speakerlab 15, which had a leaf tweeter, 8" poly cone woofer, and 10" PR on front of a tower type cabinet. The Speakerlab 17 consisted of the same leaf tweeter, a 6" poly cone mid, 8" poly cone woofer, and 10" PR on the back of a tower type cab.
This "AHR" worked in conjunction with the woofer down where the woofer would have begun to roll off. The AHR itself was rolled off higher up where the woofer was more effective.
The Type Five consisted of a leaf tweeter, 2" Dome upper mid, 6.5" poly cone mid, 10" woofer, and 12" active radiator. The Type Four consisted of a leaf tweeter, 4" mid (a Polydax unit), 8" poly cone woofer, and 10" active radiator. Both were in tower type cabinets.
They also had their Speakerlab 15, which had a leaf tweeter, 8" poly cone woofer, and 10" PR on front of a tower type cabinet. The Speakerlab 17 consisted of the same leaf tweeter, a 6" poly cone mid, 8" poly cone woofer, and 10" PR on the back of a tower type cab.
This "AHR" worked in conjunction with the woofer down where the woofer would have begun to roll off. The AHR itself was rolled off higher up where the woofer was more effective.
MarkAnderson
Addicted Member
dnewma04;1898042...they also have less port noise...[/QUOTE said:
kfa888
Addicted Member
Only Speakerlab i have heard was Tators Model 7 (I think) and it had the 10" / 12" deal. Those suckers ponded it out, HARD. Not the most civilized sound i have ever heard but WOW, it was powerful.
For some goofy reason I like passive radiator speaker better than most ported speakers i have come across. Passive radiator speakers i have owned are...
Genesis II's
EV Interface II
Pioneer S-1010
All were / are good sounding.
