I have some cheap but functional aftermarket speakers from Walmart and a cheap touch screen head unit found online so i'm honestly not sure the brands. But i have a 2001 ford explorer sport trac and ever since i put the radio in i have had the issue where the speakers crackle with the music or bass but only when the engine is running. If i turn the truck on to accsessory with the engine off i can crank the speakers up loud and they sound perfect. If anyone has any slight info about this i would appreciate it