Just bought a 2004 Accord LX Coupe (Silver/Black) and really love it. However, I noticed a tizz from the right rear speaker when certain bass frequencies occurred. It was driving me crazy. I opted for a home remedy since I find that when dealers start screwing around with stuff, they usually make it worse.

Anyway, I opened the trunk and looked at the speaker from underneath (a cheapo Pioneer made in Mexico). I noticed that there was an opening where the cone was exposed. When I pressed my finger to the cone, the tizz stopped. SO, I got some thick, soft cotton material (cut up an old blanket) and stuffed it in the opening against the cone. The tizz was gone and my ears are happy once again.

I've read several posts on this and other forums about speaker tizz. Hope this home remedy helps.