amp got an problem

[farting4dauk]

everything is connected, the back of the head unit wasnt touched i was putting in new front speakers which are shit may i add now the sub has stoped working the amp is coming on but theres no sound in the sub all connections have been checked i duno how many times.

[Houstie]

This is common - with a bad earth.

Although the earth lead is connected - you must have a good earth, not onto coated metal, which most car chassis now have, you may need to scrape it away a little