How does a clamshell work?

[Vermithrax 10+ year member]

Ah, I am thinking of something else here. I was thinking isobaric enclosures using two drivers facing each other in a push pull configuration. My bad.

You were thinking correctly. The term "clamshell" was used long ago to describe an isobaric setup.

 

[vehementSPL 10+ year member]

Lets say basic sealed clamshell.... Say it has a 4th order aspect to it. what would the tuning be in theory... I know it depends on the size but lets talk about something like tommy mckinny's

 

[Jameseypoo 5,000+ posts]

i tried one. Now moving onto something else.

This would be a ported box

 

[vehementSPL 10+ year member]

no I know that is a ported enclosure lol. What I am saying are there any benefits to doing a clamshell as far as output other than more space for woofers and airspace

 

[vehementSPL 10+ year member]

and I may be using the term clamshell out of context . But basically subs facing each other. More so than anything 4 sides firing into each other

 

[canyouhearmatt 10+ year member]

and I may be using the term clamshell out of context . But basically subs facing each other. More so than anything 4 sides firing into each other

All hail the guy with 20 something different amps and speaker!!!

j/k...

More so than anything 4 sides firing into each other

and //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

 

[iamamp3pimp 5,000+ posts]

tommy has a diamond, and the subs dont directly face eachother

and they are all in phase with one another

 

[Immacomputer 10+ year member]

Clamshells can offer an increased gain due to increased loading on the drivers and transmission line/horn effects. The drivers in a clamshell pressure load each other and the line which can allow for greater mechanical power handling and increased output.

Don't think of clamshells acting like a bandpass because that really isn't the case unless you mass load the end of it with a port. Clamshells will are more closely related to 1/4 wave theory enclosures than to bandpass theory. In 1/4 wave theory, you have a high pressure zone that turns into a high velocity zone. The high pressure zone is the far back of the clamshell and the high velocity zone in the mouth or opening of the clamshell. This pressure transfer can cause 1/4 wave resonances that will be based on the length and geometry of the clamshell. Long clamshells will have lower resonances (like bass tunnels and Tommy's truck) while shorter clamshells have higher frequency resonances.

 

[MikeyB 5,000+ posts]

Clamshells can offer an increased gain due to increased loading on the drivers and transmission line/horn effects. The drivers in a clamshell pressure load each other and the line which can allow for greater mechanical power handling and increased output.
Don't think of clamshells acting like a bandpass because that really isn't the case unless you mass load the end of it with a port. Clamshells will are more closely related to 1/4 wave theory enclosures than to bandpass theory. In 1/4 wave theory, you have a high pressure zone that turns into a high velocity zone. The high pressure zone is the far back of the clamshell and the high velocity zone in the mouth or opening of the clamshell. This pressure transfer can cause 1/4 wave resonances that will be based on the length and geometry of the clamshell. Long clamshells will have lower resonances (like bass tunnels and Tommy's truck) while shorter clamshells have higher frequency resonances.

Interesting. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[duece212 5,000+ posts]

I've thought about a very small diamond of 4 15's sealed in the extended cab of my truck. No idea how it would act, but would be interesting to try. Not sure if there would be enough cone area to make any thing different happen, but the volume and opening of the diamond would be smaller than any of the others mentioned.

 

[iamamp3pimp 5,000+ posts]

im guessing the angle of the mouth changes how it sounds as well?

 

[duece212 5,000+ posts]

im guessing the angle of the mouth changes how it sounds as well?

Would guess its angle/direction would have a big impact on where it gets loudest in the vehicle too. All things I'm too **** lazy to test/try/figure out

 

[TSGP]

But a diamond definately does act like a bandpass and you are totally wrong to think it doesn't.

The depth of the baffle along with the way the woofers load is what gives the tuning

 

[audioholic 5,000+ posts]

As already stated, all car audio subwoofer systems act as a quasi-bandpass. I dont see how that is necessarily affected by the shape of the enclosure being a clam shell.

 

[TSGP]

because...

a bandpass box loads pressure and tunes that pressure and acts like one big driver.

And what do you think a diamond does?