2. speakers
  3. 133747-2227

Why so few speakers with Passive Radiators?

Folks,

What are your thoughts on Passive Radiators in speaker design?

I've had many different speakers (and like many here, have heard countless varieties outside my home), from ported, to sealed, to passive radiator, to transmission line.

In my experience by far the best bass has come from the Thiels I've owned - CS6, 3.7, 2.7 which use passive radiators.  The bass in these designs are punchy yet as tonally controlled, or more, than any other speaker design I've heard.  So I figure the choice of a passive radiator must be involved somehow, and it makes me wonder why more speaker designers don't use this method.  It seems to give some of both worlds: extended bass, no port noise, tonally correct.

And yet, it seems a relatively rare design choice for speaker manufacturers.

Thoughts?
prof
mapman's avatar
mapman
22,464 posts
 
I am almost always impressed by speakers that make good use of passive radiators compared to the competion.

I picked up an 8"front firing Klipsch sub with two side firing passives recently. Was originally looking at much bigger bulkier subs but this little thing competes with the much bigger boys in every way.

I vote for more passive radiators!
davide_845
1 posts
 
A passive radiator is expensive compared to a tube.
It could be a reason why it is rarely used.

With a passive radiator you don't have port noise, but it's not true that there aren't sound at mid frequency that go out from passive radiator.
At mid frequency, passive radiator cone interacts with a woofer cone.
If you use a low pass filter at low frequency you will not have any problems.

With a passive radiator or port you can choose damping of your system and you can get the same result in the listen experience...with an ideal passive radiator!

I don't like passive radiator due to non linearity of the suspension.
Speakers is a really complex non linear system, if we add another non linear component you can loose some performace.

tomcarr
1,543 posts
 
I'm on the bus, too. My Vandersteen 2Cs are a 3-way, with an acoustic coupler on the back of the speaker. Are they considered acoustic suspension? Ported? Sealed?
Thanks for a response, and thanks Prof for this post>

Tom
rodman99999
6,188 posts
 
Systems utilizing passive radiators ARE, "vented" systems. The Thiele-Small parameters and calculations, are identical for both. Only the application(vent or radiator) of the results(mass of port air/size and weight of the radiator), varies. https://itstillworks.com/size-speaker-enclosure-passive-radiators-7918995.html   "Tighter" bass can be realized, by adding weight to the radiator(s).
tomcarr
1,543 posts
 
Sorry, forgot to ask is an acoustic coupler the same as a passive radiator?

Tom
More to discover