Do You Miss Acoustic Suspension Speakers?

[Edgar Betancourt]

You, evidently, misunderstood my intentions when I posted those quotes. They were directed at you.

No, I understood perfectly. You missed to apply the responses in context.

 

[Edgar Betancourt]

No, I understood perfectly. You missed to apply the responses in context.

 

[Edgar Betancourt]

I learned something today. I was also of the mindset that all sealed speakers were acoustic suspension but clearly I was wrong. In laymen's terms what sets the driver apart from an acoustic suspension to a sealed design? Is the bass roll off similar in acoustic suspension as it is a sealed design?

Because I didnt know any better, I would say no, I do not miss acoustic suspension speakers.

Don't feel bad you were right to begin with! The fact that a an incorrect statement is repeated ad nauseum doesnt make it right.

 

[shadyJ]

Edgar I don't know why you are so hellbent on being right about this. I don't agree with your position, but, to be honest, I don't worry too much if someone else has a misconception about the definition of acoustic suspension.

In addition to the listed experts that peer-reviewed this article, Audioholics talked to other transducer engineers about the subject. Everyone was on the same page about the meaning of 'acoustic suspension.' Maybe you should just talk to a transducer engineer or speaker designer about the subject, like we did. You say you have a medical degree, well you probably wouldn't want a non-expert lecture you about the areas that you hold expertise in, right? If this subject elicits so much passion in you, you might want to double-check your ideas about this subject with people who hold expertise here.

 

[Edgar Betancourt]

Edgar I don't know why you are so hellbent on being right about this. I don't agree with your position, but, to be honest, I don't worry too much if someone else has a misconception about the definition of acoustic suspension.

In addition to the listed experts that peer-reviewed this article, Audioholics talked to other transducer engineers about the subject. Everyone was on the same page about the meaning of 'acoustic suspension.' Maybe you should just talk to a transducer engineer or speaker designer about the subject, like we did. You say you have a medical degree, well you probably wouldn't want a non-expert lecture you about the areas that you hold expertise in, right? If this subject elicits so much passion in you, you might want to double-check your ideas about this subject with people who hold expertise here.

I posted 4 articles on the subject including the original AR3 owners manual and description. It just simply pisses me off....

 

[Matthew J Poes]

Not acoustic suspension, those are just sealed designs.

James I tend to think NHT probably are really Acoustic Suspension. Hard to know for sure, but that has been my understanding of their use of sealed designs in the past.

 

[Matthew J Poes]

I posted 4 articles on the subject including the original AR3 owners manual and description. It just simply pisses me off....

I probably don't want to wade into this, but I will anyway.

Can you repeat what you believe an acoustic suspension design is? What you are arguing? Are you suggesting that any small box sealed design is by nature an acoustic suspension as Edgar Vilchur intended in his patent?

 

[Verdinut]

An acoustic speaker cabinet must be relatively small in order to provide the necessary air-spring (the enclosed air in a larger cabinet would not form a cushion springy enough to be effective).

That's not really exact! The Altec 411-8A Woofer can be considered as an acoustic suspension driver. It is designed to perform in a 5½ to 8 cubic foot sealed enclosure, not a small box. It has a very compliant foam suspension such as, if you could put one those drivers on a table, the weight of the moving mass would make the cone fall and touch the table top. Here is a proof that a speaker cabinet becomes an acoustic speaker cabinet simply because it encloses an acoustic suspension driver.

http://greatplainsaudio.com/wp-content/uploads/2016/06/411-8A_lfspkr_spec_sheet.pdf

 

[Edgar Betancourt]

That's not really exact! The Altec 411-8A Woofer can be considered as an acoustic suspension driver. It is designed to perform in a 5½ to 8 cubic foot sealed enclosure, not a small box. It has a very compliant foam suspension such as, if you could put one those drivers on a table, the weight of the moving mass would make the cone fall and touch the table top. Here is a proof that a speaker cabinet becomes an acoustic speaker cabinet simply because it encloses an acoustic suspension driver.

http://greatplainsaudio.com/wp-content/uploads/2016/06/411-8A_lfspkr_spec_sheet.pdf

Relatively small, note the first word relative. What AR was boasting was that they could get the bass extension of a much bigger speaker and yes the altec was a an acoustic suspension. Acoustic suspension was penned in the late 40s again before AR was founded. Have you seen speakers of the 30s and 40s. Think Atwater Kent and huge consoles and you get an idea. Basically paper with corrugated paper aurrounds the better ones had impregnated canvas suspensions! In fact the preferred audiophile speakers were horns with 15 inch woofers!

 

[Verdinut]

Relatively small, note the first word relative. What AR was boasting was that they could get the bass extension of a much bigger speaker and yes the altec was a an acoustic suspension. Acoustic suspension was penned in the late 40s again before AR was founded. Have you seen speakers of the 30s and 40s. Think Atwater Kent and huge consoles and you get an idea. Basically paper with corrugated paper aurrounds the better ones had impregnated canvas suspensions! In fact the preferred audiophile speakers were horns with 15 inch woofers!

Yes, I have seen speakers of the 1930-40's. My father owned a 1934 Deforest-Crosley Balmoral console radio using two 10 inch speakers. I also used to own an Altec 604 Dual Concentric Monitor speaker. It was a coaxial driver built in 1940 and our Canadian company, Northern Electric which was then closely related to Western Electric and Altec in the US, had built it for Altec. I figure Altec, during WWII, was then assigned to do products for the US army.

 

[Edgar Betancourt]

Yes, I have seen speakers of the 1930-40's. My father owned a 1934 Deforest-Crosley Balmoral console radio using two 10 inch speakers. I also used to own an Altec 604 Dual Concentric Monitor speaker. It was a coaxial driver built in 1940 and our Canadian company, Northern Electric which was then closely related to Western Electric and Altec in the US, had built it for Altec. I figure Altec, during WWII, was then assigned to do products for the US army.

Note the floppy statement which nowadays is the antithesis of woofer design which is all as rigid and as light as possible. However sealed was in fact a misnomer air could always permeate through the cone or the seams to reestablish air volume and maintain the air suspension. Deeper bass definitely but transient response compared to modern designs was poor. Its was what they had to work with. Today its all about excursion and quickness while maintaining cone rigidity.

 

[Verdinut]

Note the floppy statement which nowadays is the antithesis of woofer design which is all as rigid and as light as possible. However sealed was in fact a misnomer air could always permeate through the cone or the seams to reestablish air volume and maintain the air suspension. Deeper bass definitely but transient response compared to modern designs was poor. Its was what they had to work with. Today its all about excursion and quickness while maintaining cone rigidity.

Since their first release in the late 1930's, Altec 15 inch woofers drivers have always had excellent transient response. They have a low Qts of 0.25 or less due to their heavy magnets and light moving masses. For example, a 416 woofer's moving mass weighs only 63 grams.

 

[Edgar Betancourt]

In fact modern magnets are now light however they are 5 times as powerful since they are now supermagnets! The magnets on the new BW 800s look like a stack of half dollars.

 

[everettT]

Did I miss anything?

 

[lovinthehd]

Did I miss anything?

Just Edgar trying to defend his indefensible position. He's a riot.

 

[SMc]

James I tend to think NHT probably are really Acoustic Suspension. Hard to know for sure, but that has been my understanding of their use of sealed designs in the past.

NHT says they are on the website FWIW.

 

[lovinthehd]

NHT says they are on the website FWIW.

Well, some are just calling sealed designs acoustic suspension, too....

 

[3db]

Hey Shady... my questions remain unaswered in this thread. Please enlighten me.

 

[Edgar Betancourt]

NHT says they are on the website FWIW.

If they have their woofer/s in non vented enclosure they are! What Im not certain is if as originally envisioned the other drivers had their own separate box within the box too. All modern acoustic suspension and the later AR models did. Not sure if the AR 3 did as well.

 

[SMc]

If they have their woofer/s in non vented enclosure they are! What Im not certain is if as originally envisioned the other drivers had their own separate box within the box too. All modern acoustic suspension and the later AR models did. Not sure if the AR 3 did as well.

NHT also says so on this site!

Interview with NHT On Loudspeaker Design Philosophy

As long time fans of NHT Speakers, this behind the scenes interview gives you a glimpse of the reasons for their success for building no-nonsense loudspeakers for over 25 years.

www.audioholics.com

I don't see separate boxes for the two-way speaker shown.