Need help with door speaker resonance, installed all new speakers today in 04 Envoy

[ENDEE666]

Installed all new speakers today in my girlfriends 2004 Envoy, Polk DB651. They sound really good with one exception. One of the 4 doors is getting some bad mid bass resonance & muddy sound. All 4 speakers are the same, and both rear doors are the same, yet one speakers sounds bad.. Ithought it was maybe a damping issue, so I added a couple layers of dynamat to the inside of the door skin & it did not help at all... It seems to be worse with the rubber-ish factory sound deadening on. If I peel it back some, it lessens.. But why would that matter on one door and not the others? So now what should I do to fix this? The muddy sound is killing all of it...

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[KyleBechtold 5,000+ posts]

Installed all new speakers today in my girlfriends 2004 Envoy, Polk DB651. They sound really good with one exception. One of the 4 doors is getting some bad mid bass resonance & muddy sound. All 4 speakers are the same, and both rear doors are the same, yet one speakers sounds bad.. Ithought it was maybe a damping issue, so I added a couple layers of dynamat to the inside of the door skin & it did not help at all... It seems to be worse with the rubber-ish factory sound deadening on. If I peel it back some, it lessens.. But why would that matter on one door and not the others? So now what should I do to fix this? The muddy sound is killing all of it...

some of those cups for speakers..

 

[ENDEE666]

Not a fan of those baffle things. Way to small to be a proper enclosure. But still comes back to the issue why 3 of them sound fine...

 

[Rudy 10+ year member]

Do you know what is resonating? Can you stop it by pressing your hand on a specific area of the door?

 

[ENDEE666]

Ok, tried swapping the rear speakers, and the sound stayed with the door. Tightened up everything I could see but the resonance is still there. Put 2 layers of dynamat on the lower half of the door skin & no improvement...

Also put a layer of dynamat on the inner door metal where the plastic speaker housing mounts to the door metal. Still nothing. Between all this deadening and the fact the other rear door is totally fine, it really can't be a door acoustics issue.. Is it possible one channel of the stock amp or maybe wiring is bad? Its the non-bose system btw...

 

[ENDEE666]

Do you know what is resonating? Can you stop it by pressing your hand on a specific area of the door?

I banged around & did manage to kill a couple of rattles, but can not seem to find the resonating surface. Seems like its just in the door cavity.. But as mentioned above, the other door, having exactly mirrored acoustics, is fine. So I really can not see it being acoustics or even a resonance apart from something loose. And I tightened the hell out of every bolt.. Thinking its a signal issue or something. Almost seems like there is an eq boosting the heck out of 300-400 hz or so, to the point its over bearing and distorted in that range.

I will likely be getting her a new head unit as well, that may solve it if its a bad stock amp or head unit. Just so **** frustrating. Kinda relieved its not a bad speaker, but that would have been an easy fix...

 

[ENDEE666]

Do you know what is resonating? Can you stop it by pressing your hand on a specific area of the door?

I banged around & did manage to kill a couple of rattles, but can not seem to find the resonating surface. Seems like its just in the door cavity.. But as mentioned above, the other door, having exactly mirrored acoustics, is fine. So I really can not see it being acoustics or even a resonance apart from something loose. And I tightened the hell out of every bolt.. Thinking its a signal issue or something. Almost seems like there is an eq boosting the heck out of 300-400 hz or so, to the point its over bearing and distorted in that range.

I will likely be getting her a new head unit as well, that may solve it if its a bad stock amp or head unit. Just so **** frustrating. Kinda relieved its not a bad speaker, but that would have been an easy fix...

 

[ENDEE666]

Do you know what is resonating? Can you stop it by pressing your hand on a specific area of the door?

I banged around & did manage to kill a couple of rattles, but can not seem to find the resonating surface. Seems like its just in the door cavity.. But as mentioned above, the other door, having exactly mirrored acoustics, is fine. So I really can not see it being acoustics or even a resonance apart from something loose. And I tightened the hell out of every bolt.. Thinking its a signal issue or something. Almost seems like there is an eq boosting the heck out of 300-400 hz or so, to the point its over bearing and distorted in that range.

I will likely be getting her a new head unit as well, that may solve it if its a bad stock amp or head unit. Just so **** frustrating. Kinda relieved its not a bad speaker, but that would have been an easy fix...