electrical hum?

[marky67]

hi guys, i recently noticed an electrical hum on start up for about 30 secs, gos like hum stop hum stop etc it seems to be coming from the rear , any ideas
many thanks
mark

 

[mohammed]

hi guys, i recently noticed an electrical hum on start up for about 30 secs, gos like hum stop hum stop etc it seems to be coming from the rear , any ideas
many thanks
mark

rear speakers,either door ones or the 6x9's