Sound from drivers door speaker in my tru...

Ok i use to be able to crank the radio in my truck and the next state over heard it. and that was on factory speakers and i did get a different audio cd player 4 my truck. well one day the drivers side just started to crackle, so i figured i blew a speaker, put new speaker in, then i had NO sound, so out came the cd/radio player. went to wallmart, ya it was close, i wanted a mp3 player so i can get ride of 100 cds in my truck, and i got a cheap one, hooked it up,its a VRCD400-SDU plays am/fm receiver cd/mp3/wma player with USB port, Aux In & detachable face and it came with a remote, so well now i can talk loader than my sterio is playing, and and and the drivers side door speaker sounds like its on 2 and the passengers side is definatly louder, so what the frik happend i got a different speaker for door, only to discover it wasnt blown, i got a new radio whis is not load, at all, and my drivers side sounds like no sound, unless certain songs play that go from left to right. and i also dont have sound in the back, just crakling once in a while, and so we tore apart the door and took the sterio out and rewired it in and checked the wires what we could that wasnt bundled or behind the metal that u cant get at. im just pist i had awsume sound now i got granmas sound in there. i dont have alot of money to spend on equipment, something is just not right, and its driving me crazy. can i get a booster to make the sound at least a little louder, im serious u can yell loader than the sterio, before u couldnt hear anything. should i cut the back speakers off, i know that would put more sound towards the front, i am puzzled. i dont have any sub woofers or equalizer thingy hooked up to this. just the player and my speakers. thanks Creedy