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Any Acoustic Suspension AND MTM options?

The LCR-4 looks interesting, though I'd want to know what +- they're measuring to get that 32Hz low end.

A sealed box is not necessarily acoustic suspension. The fact that they cite elimination of cabinet resonance rather than bass extension as its purpose suggest that it is not. Which puts the woofers in a similar configuration to the mids of a vintage 3 or 4 way acoustic suspension model. Perhaps combining these with a pair of actual acoustic suspension subwoofers would get you to where you want to be?
 
I guess I did not know there was an actual difference between sealed-box speakers and acoustic suspension. I had always thought that sealing the box created and air spring the woofer worked with.

So..what is the difference?
 
gkimeng said:
The LCR-4 looks interesting, though I'd want to know what +- they're measuring to get that 32Hz low end.

A sealed box is not necessarily acoustic suspension. The fact that they cite elimination of cabinet resonance rather than bass extension as its purpose suggest that it is not. Which puts the woofers in a similar configuration to the mids of a vintage 3 or 4 way acoustic suspension model. Perhaps combining these with a pair of actual acoustic suspension subwoofers would get you to where you want to be?
Click to expand...

I don't think that those could be IB, in that small of a box.

The "resonance elimination" is in reference to the cabinet walls, themselves. Not the acoustic energy inside the box.

As for the 32Hz- it does rely on some boundary reinforcement, for that to happen. But, in a real room, installed "normally" (near a wall), they do actually produce usable bass down to the low 30s, no problem.

Regards,
Gordon.
 
RVT1K said:
I guess I did not know there was an actual difference between sealed-box speakers and acoustic suspension. I had always thought that sealing the box created and air spring the woofer worked with.

So..what is the difference?
Click to expand...
In acoustic suspension the box volume needs to be an air spring that provides most the restorative force for the driver. This makes the driver motion more linear and reduces distortion. Acoustic suspension drivers are very compliant and sort of floppy. Not many drivers made today are suitable for a acoustic suspension design in the classic sense.

All sealed boxes will provide some restorative force if the box volume isn’t too big. Drivers that aren’t optimized for acoustic suspension don’t benefit as much from the air spring, and may primarily rely on the mechanical construction of the driver instead of the air spring for restorative force.

If the box volume is too large, like Bozak for example, it becomes an infinite baffle. The main purpose of that design is to keep the back wave from interfering with waves radiating forward from the driver.

Vas/Vb ratio as great as possible would be the hallmark of an AR or KLH style acoustic suspension design.

One of the big reasons you don’t see as many acoustic suspension designs is because materials science has progressed greatly since the invention of acoustic suspension. Some modern driver can get as good of linear response as an acoustic suspension driver at a lower cost, and with modern modeling it’s just as easy to tune other enclosure types like ported, transmission line, etc.
 
A23gt said:
In acoustic suspension the box volume needs to be an air spring that provides most the restorative force for the driver. This makes the driver motion more linear and reduces distortion. Acoustic suspension drivers are very compliant and sort of floppy. Not many drivers made today are suitable for a acoustic suspension design in the classic sense.

All sealed boxes will provide some restorative force if the box volume isn’t too big. Drivers that aren’t optimized for acoustic suspension don’t benefit as much from the air spring, and may primarily rely on the mechanical construction of the driver instead of the air spring for restorative force.

If the box volume is too large, like Bozak for example, it becomes an infinite baffle. The main purpose of that design is to keep the back wave from interfering with waves radiating forward from the driver.

Vas/Vb ratio as great as possible would be the hallmark of an AR or KLH style acoustic suspension design.

One of the big reasons you don’t see as many acoustic suspension designs is because materials science has progressed greatly since the invention of acoustic suspension. Some modern driver can get as good of linear response as an acoustic suspension driver at a lower cost, and with modern modeling it’s just as easy to tune other enclosure types like ported, transmission line, etc.
Click to expand...

Thanks for taking the time to explain that!
 
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