List of Acoustic Suspension Monitor Speakers

F1nut

I'm interested in compiling a list for reference, so please post the maker and model of any current or recent offerings. Price is irrelevant.

mhardy6647

Not to be persnickety, but are you interested in truly "acoustic suspension" alignments or any and all sealed boxes?

I am thinking,e.g., of the BBC LS3/5A nearfield monitor specification, which is a small sealed box but not (???) strictly speaking acoustic suspension.

All this being said, the modern-day LS3/5A clonies are the only sealed box loudspeakers that leap to mind.



Heck, even KEF's modern "visualization" of the LS3/5A -- the LS50 -- is ported.
Go figure.
https://www.stereophile.com/content/kef-ls50-anniversary-model-loudspeaker




So -- this should be an interesting list; good question!

mhardy6647

Good ol' teh interwebs turned up this, albeit from 2006-7:
http://forums.stevehoffman.tv/threads/who-today-makes-sealed-box-speakers.81619/

F1nut

Sealed design examples are welcome too.

F1nut

A few for the list.

NHT C3
DC10 Audio Berlin R

codycatalist

Didn't read post all the way through. Corrected my post.

OleBoot

I think all ATC speakers are sealed box.

rooftop59

Please explain sealed vs acoustic suspension.

And not passive radiator designs, right (which I know is a kind of port)?

mhardy6647

I haven't heard the LS50s (perhaps I am the only 'audiophile' who hasn't?), so I cannot say.

rooftop59 wrote: »

Please explain sealed vs acoustic suspension.

And not passive radiator designs, right (which I know is a kind of port)?

Without actually knowing the answer, I believe that the Villchur/Acoustic Research acoustic suspension alignment represents a way to get low bass from a small box and a woofer with a highly compliant suspension, using the air in the box as a 'spring' for the restorative force -- as opposed to a "springy" surround, like the accordion-pleated paper or treated paper surrounds common in the 1950s on consumer woofers, and still found on many 'sound reinforcement' drivers.

Having said this, I suspect there are precise definitions of the "space" that constitutes acoustic suspension loading (i.e., combination of box parameters & driver T/S parameters) -- but I am naive of them & too lazy to look 'em up! It might be instructive to look at Villchur's early patents, but then again the Thiele/Small model didn't exist at that point, so it might be hard to translate Villchur's approach to a modern point of view informed by the work of Thiele, Small & others in the intervening decades.

Nice Villchur overview from the AES:
http://www.aes.org/aeshc/docs/recording.technology.history/villchur.html

As to "other" sealed box alignments (and these are only my opinions; I am no expert!):

Even in the early days of hifi, very large sealed boxes were used with the then-common low-compliance woofers to get (fairly) deep bass (with high sensitivity). This alignment was/is known as the infinite baffle. Electrovoice, for example, in their speaker driver technical documents, often recommended installing their big drivers in a conveniently located closet to serve as an infinite baffle -- although they noted that the availablity of two appropriately located closets for stereo was often not available in the hifi enthusiast's home The woofers used in the classic infinite baffles had their own springy suspension (accordion pleat surrounds), of course -- they're the same woofers used in ported (vented) enclosures in those somewhat naive times

There are also (very) small sealed boxes that probably don't meet the formal definition (assuming there is one!) of acoustic suspension. The more I think about the resonant, "lossy" boxes of the LS3/5A monitor specification, the more I figure they're not really "sealed" in the sense of F1nut's request... although I may be treading on the slippery slope of semantics here.

mhardy6647

rooftop59 wrote: »

Please explain sealed vs acoustic suspension.

And not passive radiator designs, right (which I know is a kind of port)?

Right. Passive radiators are a special case of the Helmholtz resonator/"bass reflex" ported enclosure design. The mass of the PR takes the place of the mass of air in a Helmholtz "port" in loading the woofer at low frequencies. Note that either approach results in a deliberately resonant enclosure for the woofer. This serves to augment low frequency output at certain frequencies, but does not load the woofer as well (at really low frequencies) as would a sealed enclosure. At least, that's the way I remember it



All things being equal (I think!), the rate of bass output roll-off of a PR loaded woofer is faster (steeper as a function of frequency) than an bass reflex loaded woofer. Either alignment gives steeper bass roll-off than an acoustic suspension alignment.

Is this at all helpful? ::p

halo

ProAc Tablette 10

Unknown

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rooftop59

Yep2 wrote: »

NHT M6's.
Totally sealed.
Stereophile "Class A".

Well those are LONG out of production, but the last time i checked they were doing a a small run of a special edition...