filling gap for new speakers?

[rateat]

I keep reading around the forum that when installing new speakers you should fill the gap between the speakers because it will make it sound so much better. Can somebody explain to me what this means? What do I fill the gap with?

thanks

[gameguru1360]

they probably mean the backwave between the magnet and the body paneling. You can usually eliminate this with a material called Dynamat Extreme. It absorbs the rattling from the car's body panels

with door speakers, you can use those speaker baffles to protect the speakers from moisture and water, but they actually hinder the sound because it muffles the backwave air.

Usually though with door speakers, you don't really have to worry about backwave air as much as with subs. But using Dynamat Extreme on the door panels and rear deck really helps to eliminate the rattling or unwanted road noise.