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Discussion Starter · #1 ·
whats the difference in sound between a sub that is decoupled and one that is not, same box, same driver, same everything, one is de coupled one is not.

below 60hz :)


difference in sound is?
 

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sub decoupled from enclosure or sub+enclosure decoupled from car frame?
 

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Why would you want a sub decoupled from the baffle? You'll be losing spl when you do that. Some people even torque the screws very tightly to the baffle just to improve spl.
 

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Why would you want a sub decoupled from the baffle? You'll be losing spl when you do that. Some people even torque the screws very tightly to the baffle just to improve spl.
So you are saying the box vibrating and adding its own sound to the mix is a good thing?
 

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No. If the box is vibrating badly, then there is something wrong in the construction. That's why people brace enclosures to improve rigidity and stiffness...some people even use thicker baffles.
 

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A sub which is really decoupled would model like a leaky baffle.

Coupling the sub driver to the baffle - and the enclosure - is supposed to lend the rigidity and mass to the driver, letting it operate as completely as possible in a rigid position.
 

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I'd like to ask a question about my current install since it relates to this discussion.

Would placing thin foam in between the vehicles floor and the enclosure be considered decoupling if the enlosure is to be tightly bolted down? I want to add the foam to help ensure there won't be any kind of rubbing/squeaking noises between the enclosure and the floor. :confused:
 

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Is there a reason to de-couple subs? I've never heard of it done, sounds pretty counterproductive. Subs need to move air unlike some mid driver that can get away without a solid baffle. I've never built or used a sub box that vibrated or moved.:confused:
 

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whats the difference in sound between a sub that is decoupled and one that is not, same box, same driver, same everything, one is de coupled one is not.

below 60hz :)


difference in sound is?
60
I decoupled, somewhat, a sub from a sealed box a few years ago and spl dropped noticeably, bass also seemed less accurate/realistic. This was by no means an exhaustive study as I went right back to fastening the sub down hard to the baffle. X- over was @ 80Hz, 12dB/octave, iirc. I used a vibration damping material approx 3/4" thick between the driver and the baffle, seemed airtight at the time. I abandoned that ****s and giggles idea. Past performance is no guarantee of future results.
 

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a decoupled woofer would have the cone going 1 way and the frame the other, obviously not at exactly the same amplitude,but there would be some cancelation going on, for sure. for every action,there is an oposite and equal reaction[given the same mass]. having the basket solidly anchored to a rigid baffle greatly reduces the ''reaction'' .
 

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how would you decouple a speaker from the baffle?

isn't decoupling usually done to reduce vibrations transmitted from where the baffle is attached to the enclosure??

it would make sense to decouple the front baffle of a subwoofer enclosure from the actual enclosure.....but then you would still deal with resonances from the enclosure......


the only way i can see this realistically done is through a subwoofer front baffle being attached via a clay like substance to the enclosure....no screws involved....and the box being braced such that the resonant frequency is nowhere near the operating frequencies of the subwoofer system.....
 

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Luke, are you going to answer if you meant decoupling of the driver from the box or of the box/driver combo from the car?

If it's the latter, then Jon Whitledge's sprinter van is a perfect example of that. And I thought it was crazy how you could be listening at a fairly high volume and couldn't "feel" the bass in the floor of the van even if you were standing right next to the enclosure. You could hear the bass perfectly, but you couldn't tell where it was coming from by any tactile clues.
 

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Discussion Starter · #15 ·
Luke, are you going to answer if you meant decoupling of the driver from the box or of the box/driver combo from the car?

If it's the latter, then Jon Whitledge's sprinter van is a perfect example of that. And I thought it was crazy how you could be listening at a fairly high volume and couldn't "feel" the bass in the floor of the van even if you were standing right next to the enclosure. You could hear the bass perfectly, but you couldn't tell where it was coming from by any tactile clues.
actually im interested in both answers.

but i didnt know that monster moofa in the van was de-coupled?


imma have to throw a few layers of foam under me sub :)


hows he secured the box to the van if its de coupled?
 

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difference in sound is?
Less of it.

What I learned from abmolech (i give no credit to myself for having an original thought on this). A decoupler is analogous mechanically to a resistor electrically. If a baffle is a functional, mechanical device, you need to ask the question "what benefit does adding a resistor to it have."

In my experience, any time I've mechanically isolated the sub from the enclosure...either with carpet padding, foam, rubber, silicone, whatever...it's resulted in less SPL. A better enclosure is the answer to vibration control, not a chuck of foam. I'm totally a fan of dumping a few layers of liquid deadener into a box, though. Especially if it's made from MDF, which is obviously manufactured by the Jesuit Order as it's the most evil thing ever to appear on Earth. :eek:
 

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Mass and mounting hardware.

"The entire subwoofer system weighs well over 300 pounds (1334 N) and was mounted on military-grade, fail-safe rubber vibration isolators with a natural frequency tuned to 11 Hz, effectively decoupling the enclosure vibrations from the body of the van."
www.whitledgedesigns.com
Now things are getting interesting, I wonder where I can find said rubber isolators....

Edit: Some heavy duty mini springs would probably work very well actually...
 

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Discussion Starter · #20 ·
Mass and mounting hardware.

"The entire subwoofer system weighs well over 300 pounds (1334 N) and was mounted on military-grade, fail-safe rubber vibration isolators with a natural frequency tuned to 11 Hz, effectively decoupling the enclosure vibrations from the body of the van."
www.whitledgedesigns.com


:thumbsup: thanks
 
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