Hi... I have a Mitsu Eclipse 99 RS. Its in great condition.

I replaced all the speakers with Infinity Kappa Series brand Speakers and Installed a 6 Channel Amp to power my new speaks...

After doing so, I noticed that the door speakers resonated in certain frequencies. I assumed the speakers where bad, but ran a Test tone CD in all frequency and after hearing the resonating sound, and putting my hands on the plastic door panel, the sound dissapeared.:huh:

So, my question is, what can I use to stop the plastic door panel from resonating and creating awful noises that ruins how my new speakers sound?.

Should I put Dynamat? or something else?

BTW, I made sure all panel fasteners and screws where properly secure. But nothing.

Thanks

What size speaker did you use?
I had the same problem, it was just because the plastic door grill is weak, and kind of flimsy, enough so that the reverberation from the speaker will make the sound you describe.

I installed Infinity Kappa 625i (6.25") 3-way Round speakers. They fit perfectly in. But the tweeter part didn't go flush with the plastic panel.

So I took my dremmel and did a small cut (about 3/4 Inch hole) in the middle of the grill of the plastic panel and it looks remarkably good.

That tiny mod might of given the panel a bit of an excuse to resonate.

But then again, those speakers are more powerful than the factory ones.

Thanks for your help.