I recently got a 1992 XLT, and realized pretty soon that the back right speaker was having problems. Whenever a song that has any base at all comes on, the speaker makes a deep rumbling sound. Also, to make things worse, all the speakers have been letting out a lot of static. Anyway, I was looking to uprade the speakers, and while Im at it, upgrade the amp and sub. I looked around on some of the net stores, but I was a little confused as to what brands I should look out for and which ones I should go for. Im not looking for a 1000 dollar setup that will blow the roof off the truck, but something that will upgrade what ive got now. If anyone has any suggestions of speakers (size,watts, brands,etc)/amps/or subs that worked well in their explorer, please tell! thanks!