benefit of a "diamond" or "clamshell"

[spencer321 10+ year member]

just curious is there an added benefit in firing subs directly at eachother in a close proximity chamber with an open side, like a diamond or a clamshell? i would assume that the pressure in the "chamber" would be greater but how does that relate to in a vehicle?

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[Supergumby5000 5,000+ posts]

most commonly it is used to get more surface area for mounting subs. For example, with a plain rectangular box, the biggest i could use in my truck was two 18's. With the new clamshell, i can run four 15's, and could have done four 18's

 

[spencer321 10+ year member]

but does the firing of subwoofers at eachother in close almost isobaric alignment yield any benefits in SPL or SQ?

 

[Immacomputer 10+ year member]

It does have a benefit on SPL and frequency response. Besides being able to fit more subs in one area, it also allows the subs to load off of themselves and allow for extra cone control while still creating a lot of pressure build up in the line that is created. If the depth of the clamshell or diamond enclosure is long enough, you can get some serious pressure created in the very bottom octaves.

 

[ghart999 10+ year member]

How come this design isn't more common?

 

[jmanpc 5,000+ posts]

it requires a wall.

 

[ghart999 10+ year member]

Oh. No wonder.

 

[iamamp3pimp 5,000+ posts]

so....

how is one designed?

 

[audioholic 5,000+ posts]

The main advantage of a clam shell, as said earlier, is for added surface area to mount subs. It use to be much more common back when there were still alot of SPL guys going on the notion of a lot of subs in small sealed boxes, in an array. The school of thought of less port area, more cone area. Today the paradigm has shifted to fewer subs, lots of port area, lots of power. Efficiency + gobs of power these days, not just throwing as many square inches in your vehicle as possible.

Clamshells have never been common in daily drivers due to the complexity of the design and the size of the install. Walls aren't even that common in daily drivers, let alone this specialized version of one.