one of the speakers in my 98 Range Rover has developed a hiss. with the exception of a Clarion DVD player (VRX935VD) which was installed a few months back everything is stock. a local audio shop told me the speakers have individual amps and the hissing/interference is cos one of the amps has gone 'bad'. it was suggested that i disconnect all individual amps and get one single unit to power all the 11 speakers. any thoughts, ideas or suggestions are welcome. thanks.