Itunes streaming to airport disables internet

I have a mac book pro connected wirelessly to a wired network including 2 airport routers (wireless disabled) used only for streaming iTunes to my stereos. The music has no dropouts since being hard wired but when I stream from iTunes the internet connectivity gets spotty to disabled. I'm pinging the DNS at the same time and it's easy to see the internet problem as starting the music causes the pings to fail. I'm running OSX Mavericks with 802.3N wireless but the problem has persisted despite o/s updates and router upgrades. It seems there is a conflict in Apples protocol stack. Any suggestions would be appreciated since I hate stopping the music to use the internet! Thanks!