Why not acoustic suspension?


When I was young, late 60's early 70's, the sealed or acoustic suspension speakers were quite commonplace. Now bass reflex, ported speakers seem to be much more common. My understanding is that both speaker designs, assuming competent design will perform very well. Perhaps with the ported getting a slightly lower bass response and higher efficiency gives it the edge. Thinking efficiency though, amplifier watts don't cost that much more today so it doesn't seem like a deal maker. What I don't understand from a pragmatic corporate standpoint is why more acoustic suspension speakers aren't available. My understanding is that the sealed speaker box can be smaller which would be a plus from a cost standpoint, both in less material, lighter cabinet and more speakers could be shipped in a truck reducing shipping cost. Any thoughts as to why the industry has shifted so hard in the bass reflex direction?

61falcon

The AR9 was real acoustic suspension but a hanger on. By that time bass reflex had taken over. It became harder and harder to do acoustic suspension as bass reflex took over. Many(most?) speaker companies buy their drivers from a few main suppliers. And the suppliers build what sells. And bass reflex was what was selling. To get an acoustic suspension woofer you either had to design your own or pay a supplier to build something special for you which, of course, is more costly than standard designs.

And closed box is hard to sell now. It sounds different. Bass reflex sound is what most people have heard and what they think bass sounds like. There are very few closed box designs today. Off the top oif my head there's Magico, a top of the line design. But I don't know if they are acoustic suspension or closed box though I think they use the term acoustic suspension. They use closed box because they know it has less ringing that bass reflex.

@dynamiclinearity Wouldn't Legacy Focus SE be sealed enclosures? 

I may be too old school to "like" the new stuff. I really don't know. I get curious about the open baffle stuff, find it interesting but that's about as far as it goes for me. I have absolutely nowhere to listen to any new concepts or designs. I am very accustomed to what I do listen to and I don't ever get tired of it. I also have a pair of KEF R107's. They have a nice sound as well. 

I have to correct myself. I just looked at the Legacy Focus SE specs and it says that they are rear ported. 

Here ya go!

Acoustic suspension speakers are a specific type of sealed-box design that rely on a specially designed woofer and the air inside the cabinet for low-distortion, controlled bass, whereas general sealed-box speakers may not use this specialized driver design and may prioritize simplicity, compactness, and ease of construction.

Acoustic Suspension Speakers

Design Principle: Acoustic suspension speakers employ a woofer with very soft, compliant suspension components, and the air sealed inside the cabinet acts as a spring to return the cone to its rest position 

 

HUMAN Speakers+1

. This design provides a linear restoring force and reduces distortion, particularly at low frequencies 

 

Wikipedia+1

. The woofer’s mechanical suspension (spider and surround) primarily holds it in place without exerting most of the restoring force 

 

Audioholics

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Performance Characteristics:

Applications: Ideal for hi-fi audio where accurate bass reproduction is more important than sheer bass extension or loudness. Often used in home stereo and critical listening setups 

 

HUMAN Speakers

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General Sealed Box Speakers

Design Principle: A sealed box speaker, sometimes called a closed or sealed enclosure, does not have any ports or vents and relies on the air inside the box to provide some damping to the woofer 

 

All for Turntables

. Unlike dedicated acoustic suspension designs, it may use standard driver suspensions and does not necessarily optimize low-distortion bass behavior.

Performance Characteristics:

Applications: Commonly used in a variety of home and professional speakers, subwoofers, and bookshelf systems where simplicity, cost, and compactness are desired. These speakers may not attain the extremely low distortion levels of a true acoustic suspension speaker 

 

All for Turntables+1

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Key Differences

Feature

Acoustic Suspension

Standard Sealed Box

Woofer design

Specialized compliant driver

Standard driver

Restoring force

Air spring in the cabinet

Combination of cone suspension and air

Bass roll-off

Gentle, 12 dB/octave

Gradual, may vary depending on driver

Distortion

Very low, well-controlled

Moderate; can vary

Cabinet size

Compact yet deep bass

Compact, sometimes less bass efficiency

Efficiency

Requires more power for same SPL

Slightly easier to drive

Application focus

Audiophile accuracy and transient response

Consumer or general-purpose use

In summary, all acoustic suspension speakers are sealed box designs, but not all sealed or closed boxes are true acoustic suspension systems. The former emphasizes specialized drivers and precise air-spring control to achieve high-fidelity, low-distortion bass, while the latter prioritizes simplicity and ease of integration into a room 

 

Audioholics+3

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Why not acoustic suspension?

I prefer tuned and ported! 😎

See here and here.

Mike