Odd sound coming from dvd backups

Hi

I ve have backed up some dvds using macTheRipper or Ripit then Handbrake on the Appletv2 setting and then saved them in iTunes movies library which stores the movies on a NAS drive

When I go to play them I get a continuous unusual ‘metallic’ sound on all of the movies. Any other movies from other sources are fine when played through the AppleTV2. I can play the same movies through iTunes on my desktop and there is no problem at all

 

Anyone got any ideas?

 

Thanks

Just sorted it out

 

I needed to disable the AC3 setting in Settings menu

 

Thanks