MacBook Pro video and audio jitter with Yamaha stereo

I have a projector connected to a Yamaha Stereo. Usually, I connect my Windows laptop to the stereo via HDMI, and it gives no problems; however, since I've got a MacBook Pro now, it's giving issues. When the Mac is connected to the stereo without the sound connected, the picture is cast fine; however, when I change the sound output to the stereo as well, the sound and the image start to jitter. Is there a specific setting that I have to change? If anybody knows about this, it would be extremely helpful.