Any sealed box (acoustic suspension) speakers?

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HooStat

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Any sealed box (acoustic suspension) speakers?
« on: 1 Oct 2019, 05:15 am »
I am looking to integrate with several subs (not for volume, but for bass quality).  So I am looking for a sealed box design, 3 way (to keep the low frequencies out of the midrange), and I don't really care about bass extension since there will be subs.  I care most about the midrange, and it looks like almost anything is possible with Salk.  But I didn't see any such options on the Salk website.  Any thoughts on whether this is a realistic search?  All I have found have been Magico A3.  Any thoughts or suggestions welcome.   

sfdoddsy

Re: Any sealed box (acoustic suspension) speakers?
« Reply #1 on: 1 Oct 2019, 09:32 am »
You can always just plug the port.

JLM

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Re: Any sealed box (acoustic suspension) speakers?
« Reply #2 on: 1 Oct 2019, 12:31 pm »
Why are you interested in keeping the bass out of the midrange anyway (assuming you mean inside the cabinet)?  What frequency cutoff would you assign?  To truly do that in a 3-way speaker you'd need separate enclosure for the midrange, most of which are too small and very cubic that cause exaggeration of the back wave to reflect back through the cone and smear the sound that is found in nearly all sealed/ported designs. 

With sub(s) a sealed 2-way monitor (with 6 inch woofer to provide mid-bass body) should be more than adequate and would "keep the low frequencies out of the midrange".  If you read Floyd Toole's seminal "Sound Reproduction" you'll find the Schroeder frequency (roughly 120-200 Hz - room dependent) is the best for dealing with in-room bass peaks/dips (and placement of multiple subs near corners works best).  This modern revelation makes full range speakers dinosaurs.  OTOH crossing over that high can affect imaging (80 Hz is the traditional upper limit).  So pick your poison or compromise. 

Note that the drivers Jim usually picks are on the inefficient side (requiring more power and can limit ultimate output) and going with a sealed cabinet (if you're after upper bass) won't help in that regard. 



HooStat

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Re: Any sealed box (acoustic suspension) speakers?
« Reply #3 on: 1 Oct 2019, 01:09 pm »
Good questions.  I was trying to keep the midrange driver from having to distort when trying to play low frequency signals.  For that reason, I was not considering a 2 way monitor.  It seems to me that most of the cost of building a speaker is about low frequency extension -- larger cabinets, big drivers, etc.  If using multiple subs already, why pay for that?  Why not, instead, focus on optimizing the rest of the speaker design.  I was thinking of a speaker that with good response to 60-70 Hz (or whatever is realistic to achieve without heroic efforts at bass extension).  Having said this, I am not a speaker designer (hence, why Salk seems like a great option).  And I am not saying that they should produce no bass.  Just that the extra work to try to get to 30, 40 Hz might not really be worth it. 

ricardojoa

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Re: Any sealed box (acoustic suspension) speakers?
« Reply #4 on: 1 Oct 2019, 01:27 pm »
I like the idea of a 3 way sealed design. Sealed requires a lot less cabinet volume so you can have relative small 3 way speaker.

JLM

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Re: Any sealed box (acoustic suspension) speakers?
« Reply #5 on: 1 Oct 2019, 02:02 pm »
A worthwhile goal and makes sense since you already have subs.

A decent sealed 2-way design should reach 60 Hz (with a 6 inch woofer) which should easily integrate with multiple subs.  Yes, large cabinets, large drivers, and complex crossovers are more expensive.  The inherent complexity, size, and expense of a 3-way versus a 2-way to over work the woofer, gain extra bass, and/or output is a matter of trade-offs. 

One of more promising smaller 3-way designs is the BMR Philharmonitor, which Salk can build for you.  It uses a ribbon tweeter, Balance Mode Radiator (BMR) midrange, and 7 inch woofer and can reach 40 Hz (overkill for you).  It comes from Salk's crossover designer, Dennis Murphy.  Prices start at $1350/pair.  Unfortunately it is a ported design and only 85 dB/w/m efficient (quite low).

Another option would be Omega single driver Super 3i monitors.  Stated response down to 55 Hz, 94 dB/w/m efficient, starting at $695/pair, many different veneering options and Louis does good work.  Lots of support here at Audio Circle, but again ported. 

 

jsalk

Re: Any sealed box (acoustic suspension) speakers?
« Reply #6 on: 1 Oct 2019, 02:21 pm »
HooStat -

We can very easily build a sealed version of any 3-way speaker we produce.  That is not a problem.  It all depends on what you want the F3 to be.  Sealed drivers roll off early.  So you would want to make sure that the F3 will meet your needs.

- Jim

charmerci

Re: Any sealed box (acoustic suspension) speakers?
« Reply #7 on: 1 Oct 2019, 02:41 pm »

One of more promising smaller 3-way designs is the BMR Philharmonitor, which Salk can build for you.  It uses a ribbon tweeter, Balance Mode Radiator (BMR) midrange, and 7 inch woofer and can reach 40 Hz (overkill for you).  It comes from Salk's crossover designer, Dennis Murphy.  Prices start at $1350/pair.  Unfortunately it is a ported design and only 85 dB/w/m efficient (quite low).



Correction - they start at $2400.

WGH

Re: Any sealed box (acoustic suspension) speakers?
« Reply #8 on: 1 Oct 2019, 04:12 pm »
The Salk HT2C is a sealed design, the size would have to be tweaked to make it into a monitor.
http://www.salksound.com/model.php?model=Veracity+HT2C


I use a HT2C as a center channel speaker in my home theater, dialog is very clear without any bass overhang. I had a ported center speaker (not Salk) and because it is placed under the TV against the front wall male voices were too deep and the sound was boomy, the Salk speaker is perfect.

The Seas and RAAL drivers are very fast so you will need a fast, precise sub too.

birbygdad

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Re: Any sealed box (acoustic suspension) speakers?
« Reply #9 on: 18 Oct 2019, 10:05 pm »
I am a certified Salk Song 3/Salk Sub man now but back just after the dinosaurs croaked I was an AR guy. My first good system was built around A pair of AR5 in unfinished pine. Later I had the 3a which I used forever with the level controls all the way up! Ha! Even now I have a nice refurbed set of AR11. All of them have always had the same sort of rich warm fat sound. But now the design parameters Jim and his team use fit the bill for me. And though I imagine that Salk could make a killer acoustic suspension speaker I also imagine the cost would be greater to get the same level of performance of the present designs. But those old walnut boxes were cool.

WGH

Re: Any sealed box (acoustic suspension) speakers?
« Reply #10 on: 18 Oct 2019, 11:57 pm »
Art Dudley's Listening column in the Nov. 2019 (Vol.42, No. 11) issue of Stereophile has a very informative history and description of Edgar Villchur and his acoustic suspension speakers which are different than a sealed box speaker. The entire article is a fun read.

"Consider the acoustic suspension loudspeaker, in which the woofer is designed and manufactured with a surround and spider so loose that the drive's free-air resonance is impractically low, and its ability to restore cone position in the absence of a signal is essentially nil-unless and until that driver is fastened to a baffle of a smaller-than-average sealed box such that the springiness of the air trapped within supplies the necessary restorative force and raises the free-air resonance to a useful higher yet lower-that average frequency, all in the interest of providing deep bass extension from a less than large loudspeaker"

dB Cooper

Re: Any sealed box (acoustic suspension) speakers?
« Reply #11 on: 19 Oct 2019, 02:14 am »
'Acoustic suspension' speakers have virtually disappeared from the marketplace. Improved design methodologies have allowed much better performance from ported speakers than those of the past, when they were often associated with boomy or 'one-note' bass. Also, ports became marketing talking points somewhere along the way too. Good acoustic suspension speakers deliver not only great bass extension for a given enclosure size but also low levels of distortion. Only mfr I know still making them is NHT.

rpf

Re: Any sealed box (acoustic suspension) speakers?
« Reply #12 on: 19 Oct 2019, 02:21 am »
I am a certified Salk Song 3/Salk Sub man now but back just after the dinosaurs croaked I was an AR guy. My first good system was built around A pair of AR5 in unfinished pine. Later I had the 3a which I used forever with the level controls all the way up! Ha! Even now I have a nice refurbed set of AR11. All of them have always had the same sort of rich warm fat sound. But now the design parameters Jim and his team use fit the bill for me. And though I imagine that Salk could make a killer acoustic suspension speaker I also imagine the cost would be greater to get the same level of performance of the present designs. But those old walnut boxes were cool.

My first good set of speakers were also AR5s. Loved them. As much as I liked the 3As, particularly in a large room, I always found the 5s more coherent. And yes, those walnut cabinets were beautiful.

dB Cooper

Re: Any sealed box (acoustic suspension) speakers?
« Reply #13 on: 19 Oct 2019, 02:49 am »
My first good set of speakers were also AR5s. Loved them. As much as I liked the 3As, particularly in a large room, I always found the 5s more coherent. And yes, those walnut cabinets were beautiful.

The midrange in the 3a was too small and there was a dip in between the woofer and the mid due to the fact that the two drivers didn't quite 'meet in the middle'.
Agreed, the 5 was a classic; my first intro to high fidelity was via my next door neighbor's AR4ax's. (His younger brother got Large Advents for his first system.) I later owned Allison Fours and CD8's, both of which were acoustic suspension.

rpf

Re: Any sealed box (acoustic suspension) speakers?
« Reply #14 on: 19 Oct 2019, 09:34 pm »
The midrange in the 3a was too small and there was a dip in between the woofer and the mid due to the fact that the two drivers didn't quite 'meet in the middle'.

Yes, that was the problem.

DMurphy

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Re: Any sealed box (acoustic suspension) speakers?
« Reply #15 on: 20 Oct 2019, 05:29 am »
The midrange in the 3a was too small and there was a dip in between the woofer and the mid due to the fact that the two drivers didn't quite 'meet in the middle'.
Agreed, the 5 was a classic; my first intro to high fidelity was via my next door neighbor's AR4ax's. (His younger brother got Large Advents for his first system.) I later owned Allison Fours and CD8's, both of which were acoustic suspension.

The 3a's and 4x's (my first speaker) certainly had problems.   All the classic AR speakers--the 2's, 3's, and 4/'s shared a muted sound signature that made it seem like someone had lowered a velvet curtain over them.  I always assumed it was due to a shelved down tweeter or a gap in the response someplace.  But in the last four years I've had the opportunity to mod two pairs of 3a's and and one pair of 4x's, and that's not the problem.  In the case of the 4x, the gremlin  was a huge diffraction peak at the low end of the tweeter response centered at 1 kHz that the AR crossover guru's didn't deal with.   That's what was covering up the tweeter detail further up:



That problem was easy to correct, and with a modern crossover the 4x is capable of very smooth response (although the limited dispersion of the large cone tweeter still produces a somewhat closed-in upper treble.)



The AR3a had bigger problems due to the ad hoc arrangement of the three drivers.  They were all over the place, and that caused severe cancellation modes both on and off axis.  All those dips messed up the upper midrange and treble and helped produce a withdrawn character.  Equally important, the woofer had a large peak between 500 Hz and 1 kHz  that the crossover designers again didn't address, and the result was the same kind of smeared sound that plagued the 4x.  The midrange itself had plenty of output down to the crossover point of about 600 Hz, and the hazy sound was due to too much output in that region, not too little.  I tried to fix all of that, but dealing with the interference effects between "adjacent" drivers was impossible.  Still, after getting rid of the woofer peak and at least improving the overall response somewhat, the 3a sounded very good.  I had no problem selling those puppies in their oh-so-60's oiled walnut cabinets. 

 



dB Cooper

Re: Any sealed box (acoustic suspension) speakers?
« Reply #16 on: 20 Oct 2019, 01:08 pm »
Glad you chimed in, Dennis.

For those too young to remember, the signature Dennis describes was often referred to as "the New England sound." As opposed to the s-called "West Coast" sound, JBL being one example.

Paul K.

Re: Any sealed box (acoustic suspension) speakers?
« Reply #17 on: 20 Oct 2019, 01:32 pm »
When I was in college working on my BSEE in the late-'50s and early-'60s, I worked part time at a High Fi shop near campus.  It was actually the home of the owner/operator with the front part of the house devoted to the business.  I mostly built Dynaco Kits for his customers that didn't feel up to it themselves, but occasionally "minded" the store.  The owner's name was Sam and he featured Dynaco electronics for powering AR speakers for demos.  I probably heard many different AR speaker models and they all sounded pretty good to me, but what the heck, I was still young and uneducated/experienced in audio.  Because of working for Sam I was able to go to one audio show in Chicago with him where I met and chatted with Edgar Villchur, and also heard a live versus recorded demo of a string quartet using Dynaco and AR products.
Paul

rpf

Re: Any sealed box (acoustic suspension) speakers?
« Reply #18 on: 20 Oct 2019, 04:15 pm »
When I was in college working on my BSEE in the late-'50s and early-'60s, I worked part time at a High Fi shop near campus.  It was actually the home of the owner/operator with the front part of the house devoted to the business.  I mostly built Dynaco Kits for his customers that didn't feel up to it themselves, but occasionally "minded" the store.  The owner's name was Sam and he featured Dynaco electronics for powering AR speakers for demos.  I probably heard many different AR speaker models and they all sounded pretty good to me, but what the heck, I was still young and uneducated/experienced in audio.  Because of working for Sam I was able to go to one audio show in Chicago with him where I met and chatted with Edgar Villchur, and also heard a live versus recorded demo of a string quartet using Dynaco and AR products.
Paul

Cool.   :thumb:

DMurphy

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Re: Any sealed box (acoustic suspension) speakers?
« Reply #19 on: 20 Oct 2019, 06:53 pm »
Cool.   :thumb:

There was an identical operation in Ann Arbor Michigan, only the owner (and resident of the living quarters behind the listening room) used an AR amplifier to drive 3a's.  He discounted them, and because of that no other dealer was willing to take on the AR brand.  AR the company was extremely customer oriented, probably reflecting the founders' academic backgrounds.  Although AR at one time had 1/3 of the speaker market, their refusal to fair trade (i.e. only selling to dealers who would charge the list price) eventually did them in.  I'm sure their crossover work was done in good faith, but there wasn't much science to go on in those days, and AR didn't understand the importance of proper driver placement and its effect on driver interference patterns.