Greetings, new member here.
I've a speaker fitment issue I'm hoping you can help me with. I've a 1993 Toyota MR2 Turbo, in which I've replaced the factory double DIN stereo with a single DIN Kenwood KDC-X991. As the Kenwood isn't compatible with the factory speakers, I'm replacing the door speakers with Boston Pro60 SE 6 3/4" component speakers, and the rear side panel speakers with Polk DB501 5" Coaxials. I won't be using or replacing the factory tweeters and subwoofers at this time.
The rear factory speakers had a cardboard ring - or spacer - kinda like a 3 1/4inch dia tube just 1/8" long, that fit between the speaker and the plastic side interior panel.
As I'm having to mount the replacement speaker deeper into the side panel space because of the center tweeter sticking out more, that 1/8" space has grown to 1/4". (I want to retain the factory look, and would rather not cut the side panel.) Do I need to fill that space? And, if so, with what? Like a foam ring or something? Some kind of spacer? A foam ring might make sense as it won't vibrate against the side panel, but does it make sense acoustically? Are such things commercially available? Or, any tips on how to fabricate them?