99-03 cab pressure from subs

[los33 10+ year member]

As many can see from my sig i drive a 2000 gmc sierra 3door version.

I have tried keeping a single sub setup until i can make time to work on a wall, but due to the OTC (Offshore technology convention) coming soon i have been busy.

I have always noticed if my windows are closed the pressure is not as strong as my windows being opened.

I have test from 1 cuft to 4 cuft to see if space was an issue, but it has all come down to the 2 back wall vents releasing all the pressure causing my sub(s) to get weaker when windows are up.

Has anyone found a solution other then a wall?

I have not deadened the back wall and all stock stuffing has been removed so the vents are exposed.

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[adulbrich 5,000+ posts]

Unless you spend a lot of time tweaking things for sealed numbers, you'll always be louder with windows down or door open.

My car is soooo much louder with one window down than sealed

 

[los33 10+ year member]

Unless you spend a lot of time tweaking things for sealed numbers, you'll always be louder with windows down or door open.
My car is soooo much louder with one window down than sealed

I was afraid of that //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif.

Trunk builds are loud with closed windows.

I guess my only choice is to deaden and possible make a false wall to try to re-cooperate some from blocking the vents.

If i was to block the vents full on id be afraid of my ears blowing out as soon as the sub bumps with the windows closed.

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[Jeffdachef 5,000+ posts]

even my sienna and past corolla was a lot louder with windows down or door open. Its just vehicle acoustics man. With stuff open, the wave gets to travel fully, car is like a ported box. Closed up its like a sealed box.

 

[adulbrich 5,000+ posts]

even my sienna and past corolla was a lot louder with windows down or door open. Its just vehicle acoustics man. With stuff open, the wave gets to travel fully, car is like a ported box. Closed up its like a sealed box.

Yea, I was thinking about the car as a ported/sealed box too.

There's more pressure in a ported box than sealed box, so it would make sense that a "ported" car would be louder than if it was sealed up.

 

[Jeffdachef 5,000+ posts]

theres a more proper explanation for it but I forgot what it was lol. Reverted back to noob analogies.

 

[shauncox26]

Not always true. My honda is louder sealed while driving. Parked i gain a little from opening the sunroof. I gain cabin pressure with the sunroof open but to the ear my bass is just as loud as sealed parked, if that makes sense.

 

[FML 10+ year member]

As many can see from my sig i drive a 2000 gmc sierra 3door version.
I have tried keeping a single sub setup until i can make time to work on a wall, but due to the OTC (Offshore technology convention) coming soon i have been busy.

I have always noticed if my windows are closed the pressure is not as strong as my windows being opened.

I have test from 1 cuft to 4 cuft to see if space was an issue, but it has all come down to the 2 back wall vents releasing all the pressure causing my sub(s) to get weaker when windows are up.

Has anyone found a solution other then a wall?

I have not deadened the back wall and all stock stuffing has been removed so the vents are exposed.

Sent from my Z970 using Tapatalk

Dont know what happened to Post i just made...oh well.

Anyway, i drive a 98 Sierra Extended cab and also have been thinking about this too. The more I add to it, the more i feel i should just try and wall it off once and for all haha.

But, what vents are you referring to?

 

[los33 10+ year member]

Dont know what happened to Post i just made...oh well.
Anyway, i drive a 98 Sierra Extended cab and also have been thinking about this too. The more I add to it, the more i feel i should just try and wall it off once and for all haha.

But, what vents are you referring to?

The vents placed in the back wall between the cab and the bed.

98 should have the same thing. All it does is depresurises the cab, because if it didnt a door slam after a long drive can cause a nasty high altitude effect on the human body.

All vehicles have them, but trucks are more visible then how normal cars are.

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[FML 10+ year member]

The vents placed in the back wall between the cab and the bed.
98 should have the same thing. All it does is depresurises the cab, because if it didnt a door slam after a long drive can cause a nasty high altitude effect on the human body.

All vehicles have them, but trucks are more visible then how normal cars are.

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Really. I honestly have never seen them on my truck. I do a lot of work on that part of my truck too. Are you talking about on the wall behind the rear seat cushion under the rear window?

 

[wew lad 5,000+ posts]

Yes, I have a 00 chevy silverado ext. cab. I didnt think I had the vents either, but I promise you they're there. Check behind the rear passenger seat behind and below the plastic panelling.

 

[los33 10+ year member]

Really. I honestly have never seen them on my truck. I do a lot of work on that part of my truck too. Are you talking about on the wall behind the rear seat cushion under the rear window?

Yes just behind the factory padding. Some have plastic panels over it.

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[adulbrich 5,000+ posts]

The vents placed in the back wall between the cab and the bed.
98 should have the same thing. All it does is depresurises the cab, because if it didnt a door slam after a long drive can cause a nasty high altitude effect on the human body.

All vehicles have them, but trucks are more visible then how normal cars are.

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I know my 2007 Silverado has vents in the back, but my car has nothing of the sort. Firewall in the back, and sealed up in the front. Nothing on sides, top, or bottom either.

 

[los33 10+ year member]

I know my 2007 Silverado has vents in the back, but my car has nothing of the sort. Firewall in the back, and sealed up in the front. Nothing on sides, top, or bottom either.

Your vents are either run through the door on the bottom where the water drains or it is a vent on the floor or even uptop the firewall.

Even thru the actual ac vents.

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[adulbrich 5,000+ posts]

Your vents are either run through the door on the bottom where the water drains or it is a vent on the floor or even uptop the firewall.
Even thru the actual ac vents.

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Just checked my doors and they are sealed on the bottom. No vents on the floor, I've had it on a lift several times. Nothing uptop the firewall, I've had the entire interior torn out before.

Not through A/C vents either. They are currently hanging on the wall in my garage.

There are not vents like this in my car, period.