Audio promblems

[David]

Ok im having a massive problem with my cars audio atm. Iv just installed my new head unit into her and changed the front speakers to sony so im running sonys all round with a JBL sub, was working perfect till suddenly all vocal audio started to skip evn on the radio then suddenly cut out so i only had bass running thgrough the sub?

secondly my front right speaker and my rear left speaker wont work but iv swapped all the speakers around now and they all work 100% apart from when they are in the front right and rear left :S

any ideas people?