Would the optimal viewing distance really be 225 feet for a 50 foot TV? How did you calculate that?
On a more serious note, most home theater items such as a DVD player or cable TV box have multiple audio outs which makes it easy to connect to both a TV and a receiver for surround sound.
For example, my DVD has:
-HDMI (audio)
-Toslink / optical
-Coaxial / digital
-standard red/white analog audio
The challenges with a Mac Mini:
-How do you get digital audio into the TV?
-How do you get audio into a TV and a receiver simultaneously?
Since some (most?) TVs do not have digital audio inputs, your choices are either analog, or some complex adapter that combines audio and mini display port into HDMI such as this
KANEX adapter. But then if you use the audio out port on the Mac Mini for this adapter, how do you get audio into a receiver?
So let's say you use the USB audio KANEX adapter. Can you get audio from both the audio out jack and the USB port at the same time?
Has anyone tried the KANEX adapter or something similar? How did you get audio to your TV?