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Discussion Starter #1 (Edited)
Hello folks,

Ongoing install in my BRZ.

I've been working on my audio build for the past two years. I have spent a lot of time dampening the outer and inner door, and then building fiberglass panels that cover and seal all the holes on the inner door. When I went to equalize the front speakers, I found out that after all my "work", the frequency response of the right speaker (left side was fine) was being affected. It was creating a huge 12db boost from 40-110Hz and a huge 12db drop from 210-450Hz. As such, instead of a relatively flat lower/mid bass response, I have a huge peak and dip varying 27db! Everything is flat, EQ is off on the headunit, and the miniDSP is also flat except for timing adjustments. But that shouldn't have an effect as I'm only testing the one speaker in isolation.

The blue line is with the door card, and the burgundy line is without the door card (everything else stays the same on the inner/outer door). I even redid the front gasketing that seals the speaker front wave to the door and it looks perfect. Both sweeps were done back to back, same test conditions, settings, everything, except for the presence or absence of the door card.

Any suggestions? I think I need some expert help here.
 

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add more damping material to the doorcard, also use some CCF where you can, and avoid contact of two different hard materials (metal/ABS plastic) - decouple doorcard from metal
 

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Discussion Starter #6
add more damping material to the doorcard, also use some CCF where you can, and avoid contact of two different hard materials (metal/ABS plastic) - decouple doorcard from metal
thanks, will try that. Need to go buy some CCF and get that installed.
 

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Discussion Starter #9
just an additional thought -- now that the doors are fully sealed, all the backwave energy has nowhere to go and is exciting the door, and in turn exciting the door panel. Is that a fair understanding what might be going on?

Attached another chart which shows the new green line where the fiberglass paneling was removed with the door card in place.
 

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I cut the denim/plastic stuff off my cards and deadend them really well then used high temp hot glue to re attach the stuff after. When I pull my door card next time I'll remove the denim and add ccf over the whole card or inner door panel for vibrations.
 
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