I just installed a new head unit and 6.5" door speakers in my '95 Civic Coupe. Unfortunately I can't turn the stereo up very loud because the whole door seems to rattle and it's unbearable.

Anyone install aftermarket speakers and what did you do to cut the rattle down?
I know Dynamat exists, problem is it's expensive. And does it (or an equivalent) really work for this level of door noise?

 

Is it the door vibrating or something loose? Sometimes the latch and lock connector rods will vibrate if the nylon guides break. Did the panel clips break when removing the panel? That will allow the panel to vibrate. There are many dynamat like products out there. Most are expensive but effective. I like second skin. Works well.
You need to isolate the sound before you can accurately fix it. Does the sound go away when you push on the panel, lightly pull on the door latch, press on the outer door skin? Once you isolate it, then you can more easily fix it.

 

That's the problem, it sounds like it's coming from everywhere on the door. The whole panel vibrates, as does the glass. I cannot really isolate any one spot by pushing on the panel.
The clips are all there, and when no music is playing the panels feel securely fixed.

I don't have a problem using a dynamat-like product but I'd just like to know if anyone else has experienced rattle this bad and found the solution in dynamat.

 

What you will have to do is use a dynamat type product on the outer and inner metal door panels (on the inside of the door of course) then use a carpet padding material between the panel and door. (Make sure to use one that has a mildew resistant property to it)
That should eliminate the vibration.

The other issue is that you may be pushing too much bass to the door speakers. Most 6.5" speakers won't take that kind of abuse long.
If you are running a sub, reduce the bass to the door speakers and cross them over at about 70 - 100Hz depending on where you cross over the sub.