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I have built HUNDREDS of boxes (contracted for a few shops that didnt have the space/tools).

I have always built boxes to the spec as supplied by the manufacture.....but....even after talking to an engineer from Stillwater (back in the day) he was not entirely (he did some some weed from time to time) sure.....


Basically the physical volume of the driver itself (magnet, frame and cone) inside the box in a conventional mounting configuration subtracts from the internal volume of the box.....And now with subs that have GIANT frames/magnets I was wondering if anyone takes into account the loss in internal volume and builds the box larger to compensate?

I am about to build an SQ system in my personal vehicle....should I make the box bigger then spec or do the manufactures account for this?

TKS,....

~JH
 

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i'm not the expert in this, but my assumption has been, if a manufacturer recommends a volume, then you do not have to subtract for driver.

if you are doing the calculations yourself, then you should.

and the same goes for port tube.
 

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Ive seen some spec sheets that do not include driver displacement in recommended box sizes and some sub manuals that do. My guess is that it would depend on the company. Sorry I couldnt be more helpful.
 

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As far as I can tell anyway the only correct answer is it depends. Back in the day Kicker used to reccomend a net box volume and provided the displacement of the mounted sub. My current JBL manual simply recommends the actual box volumes depending on sealed of ported.

I'm guessing its more of a marketing gimmick than anything. When Kicker used to say a 10" Solobaric only requires a 0.66 ft3 sealed box I think it was advertized as one of the smallest box sizes needed. In reality though, you had to add the 0.15 ft3 (or whatever it was?) and any bracing to the box volume which put it right up there with the other subs on the market.
 

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As far as I can tell anyway the only correct answer is it depends. Back in the day Kicker used to reccomend a net box volume and provided the displacement of the mounted sub. My current JBL manual simply recommends the actual box volumes depending on sealed of ported.

I'm guessing its more of a marketing gimmick than anything. When Kicker used to say a 10" Solobaric only requires a 0.66 ft3 sealed box I think it was advertized as one of the smallest box sizes needed. In reality though, you had to add the 0.15 ft3 (or whatever it was?) and any bracing to the box volume which put it right up there with the other subs on the market.
Seems like the bottom line is pay attention to your spec sheet. My JL spec sheet for my 12w3's gives a box dimension with the driver displacement figured in. In other words if you do the figures and subtract the displacement of the sub you come up with the correct volume they list.
 

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Depends on manufacturer. Most manufacturers have compromise boxes and are not ideal if you want the most out of your woofer/ linear response.
 

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Depends on manufacturer. Most manufacturers have compromise boxes and are not ideal if you want the most out of your woofer/ linear response.
I couldn't agree more. If you go with what the manufacturer recommends it will probably sound pretty decent. Realizing of course that manufacturers are trying to protect their products from future warranty claims, and hence their bottom line, they are going to recommend fairly safe parameters. Just look at all the warnings about running a sealed sub in a larger than recommended box resulting in over excursion and subsequent damage. Can it happen? Absolutely! But with just a slightly larger box comes significantly improved performance in many cases and done correctly it's perfectly safe. Or how about more than recommended power? Is it possible to smoke a voicecoil or two? Yep? But again, done correctly some speakers go from so-so to OMG!


If you want peak performance, take all the sub's specs and model it in a box program and build it accordingly. Then tweak as necessary.
 

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why couldn't you just vacuum seal the the sub in a bag of some sort, place it in water to see how much it displaces, then use that number to add/subtract from the box volume?
 

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I suppose you could do that, if you had the means to do so. Probably just be easier to check spec sheets or Google. Most likely, if the manufacturer goes to the extent of recommending a box size they will likely provide the displacement spec of the sub or a box size already accounting for the subs displacement.

Additionally, if you wanted to model the box in a software program you would need more specs than displacement.
 
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