Baluns are sort of like transformers. I was talking about a pre-made HDMI cable that you mentioned. 5' is not the limit, I think somebody dropped a zero. 50' is about the limit for HDMI. For greater distances the cat5e route is recommended. Here is the specific link for the baluns: http://www.keydigital.com/IW_Product...RX&Company=KEY
The new ones use a single cat5e/6/7.