When I replaced my front stock speakers, I opted for the JL C3's. I did everything you guys normally recommend. I deadened the hell out of the doors, sealed them up tight. I got custom speaker baffles, fine strand silver cladded copper OFC wire. But I did forget to use foam surround between the speaker and door panel. The gap couldn't have been much, an inch if that.
Ultimately, they lacked that punch. They otherwise sounded fine, just not punchy like some OEM premium systems have. I never thought once about sealing any gap there might be between the speaker and door panel and let it be at that and moved on.
I happened to catch a video showing some overpriced surround foam being placed with him discussing mid bass. I didn't think that alone would make a difference....boy was I wrong. Today I finally got around to it and used some close cell foam weatherstripping. These things now had all kinds of mid bass, very punchy, enough to vibrate my seats and rear view mirror.
I never would of thought that little inch gap would prevent mid bass drivers from doing that.
