I'm inFInitely Baffled.

[ramos 5,000+ posts]

but that's not IB, though it would probably be terriffic. I'd be willing to beta calculated AP membrane would be ideal for that experiment.

What wouldn't be IB? Cutting a hole to vent outside? //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[James Bang 5,000+ posts]

a foam mattress might take up all the airspace in my trunk. I'd prefer to sleep on my foam mattress than put it in my trunk.

 

[aworldcollision 10+ year member]

we're not looking for absorption or isolation. it doesn't matter how thick the foam is. Its a matter of soundwave diffraction VIA completely nonreflective surfaces.

 

[aworldcollision 10+ year member]

What wouldn't be IB? Cutting a hole to vent outside? //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

the purpose is to seperate the front from the rear. Period. Rather than attempt to control the airflow, IB is monitored for mechanical limits.

The question was about sound diffraction and cancelling NOT a barrier or filter in which thicknesses would be calculated.

 

[James Bang 5,000+ posts]

I think I need to do a little test to see if I can noticed a difference in response w/ the trunk open and closed..

I should've did that the last time I RTA'd my rig.

 

[ramos 5,000+ posts]

the purpose is to seperate the front from the rear. Period. Rather than attempt to control the airflow, IB is monitored for mechanical limits.
The question was about sound diffraction and cancelling NOT a barrier or filter in which thicknesses would be calculated.

Isn't the purpose of any enclosure/ baffle to seperate the front wave from the rear wave? To prevent cancelation? What is IB? usually suggested as at least 10x the vas? Wasn't it brought up earlier that a trunk is not a true IB setup? Needs to be larger to truly be IB? //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[ramos 5,000+ posts]

I think I need to do a little test to see if I can noticed a difference in response w/ the trunk open and closed..
I should've did that the last time I RTA'd my rig.

Low end extension get's a little boomy with Dave's trunk open. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Twistid 5,000+ posts]

Can you post all pics in the first post please

 

[aworldcollision 10+ year member]

Isn't the purpose of any enclosure/ baffle to seperate the front wave from the rear wave? To prevent cancelation? What is IB? usually suggested as at least 10x the vas? Wasn't it brought up earlier that a trunk is not a true IB setup? Needs to be larger to truly be IB? //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

the purpose of most enclosures is to control air movement behind the driver. The purpose of the baffle is to seperate the front from the rear. Air control doesn't happen with IB. It was mentioned that in a car it isn't a true IB not necessarily because of the air (prolly no problem there) but because all soundwaves are joined in a vehicle and true seperation of the front waves and the rear waves are basically impossible. That's my point. With wave cancelling surfaces and, therefore, less sound in the trunk, is there any theoretical gain in performance that can be had? I'm sure not saying I know the answer, only that its a decent question.

 

[James Bang 5,000+ posts]

the purpose of most enclosures is to control air movement behind the driver. The purpose of the baffle is to seperate the front from the rear. Air control doesn't happen with IB. It was mentioned that in a car it isn't a true IB not necessarily because of the air (prolly no problem there) but because all soundwaves are joined in a vehicle and true seperation of the front waves and the rear waves are basically impossible. That's my point. With wave cancelling surfaces and, therefore, less sound in the trunk, is there any theoretical gain in performance that can be had? I'm sure not saying I know the answer, only that its a decent question.

awc.. you have a camry like mine.. try it //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

 

[James Bang 5,000+ posts]

Can you post all pics in the first post please

for you?

no.

 

[Plutoman 10+ year member]

Wow... That's an interesting thought. Going beyond the dampening of sound waves, and instead, attempting to cancel them.

To truly achieve that, you'd need to do some math. To rig it up, you'd need to align the foam properly. It shouldn't need to be extraordinarily thick - just enough to deflect the sound waves away from the front.

 

[ramos 5,000+ posts]

the purpose of most enclosures is to control air movement behind the driver. The purpose of the baffle is to seperate the front from the rear. Air control doesn't happen with IB. It was mentioned that in a car it isn't a true IB not necessarily because of the air (prolly no problem there) but because all soundwaves are joined in a vehicle and true seperation of the front waves and the rear waves are basically impossible. That's my point. With wave cancelling surfaces and, therefore, less sound in the trunk, is there any theoretical gain in performance that can be had? I'm sure not saying I know the answer, only that its a decent question.

We tested foam in the trunk, and without foam. Foam did nothing but cover the trunk. best gain we found was to actually open the trunk. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[James Bang 5,000+ posts]

I don't go to Church and I don't want my trunk to be holy...

 

[ramos 5,000+ posts]

I don't go to Church and I don't want my trunk to be holy...

Didn't cut any holes in it. I literaly mean opening the trunk lid lol. Can't get judged like that though. But there are cabin pressure relief vents in mosts trunks. We have found it's best not to seal them up. Might have to do something about the rubber flappers farting in the wind. Point I was trying to make is cancelling sound waves in the trunk is going to be harder than just making the airspace bigger. Filling the trunk with polyfill would be an interesting test, but a messy one //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif