Originally Posted by CyberCT
I'm confused about the whole "HDMI passthrough" thing. Initially, I thought a "receiver" receives both the audio and visual signals over HDMI and (1) processes the audio and outputs the audio through the speakers connected to the receiver (be it 2.1, 5.1, 7.1, etc) and (2) sends the video only to the TV.
This is the impression I was under. Then I started reading in a few places here how this receiver or that receiver just does a "passthrough" of the audio right to the TV instead of processing the audio and outputting it via the speakers connected directly to the receiver. Is this true? Then what the heck is the point of a reciver in the first place??
The cheapest receivers (the new 520 included) simply act as HDMI switches. They pass through the HDMI signal without touching it. This includes the audio and to get audio out of the receiver a separate connection (usually SPDIF) is used. This is done to keep the cost low as no HDMI processing is needed, but only the bottom of the range receivers do this these days.
An HDMI repeater (such as the 720, 820 and 920) decodes the HDMI input signal, extracts the audio portion for processing and output, then re-encodes the video portion to send on to the display.
In both cases your receiver can switch between source devices, process and playback the audio and send the video to the display device. However, the HDMI passthrough receiver requires a separate and lower quality audio connection.