Originally Posted by lovingdvd
This whole use CH1 vs CH2 vs HDMI 1 vs HDMI2 thing etc confuses me. I haven't used REW yet with HDMI (in the past always used an RCA output to one channel) so maybe it'll take some playing with it to get the hang of it. Earlier it was said in this thread that for multi-channel audio its best to use the C+Sub. I'm still confused why it's not best to use L+C+R+Sub since in my mind when watching a movie all those speakers are engaged at the same time, not just the center...? Also its confusing how we are supposed to get REW to output to all those speakers at the same time.
What is confusing? An HDMI audio connection from the PC to the AVR supports eight channels. HDMI1=left channel, HDMI2=right channel, HDMI3=center channel, HDMI4=LFE channel, etc.
REW can output to at most two channels at a time. So, in REW, select any two HDMI channels to send a signal to. If your speakers are set to small, any channel receiving a REW signal will also output the audio signal to the subwoofer channel below the speaker's crossover frequency. So, if you choose HDMI1 for REW output, you will really be sending a signal to left+sub, and HDMI2 will be right+sub, etc.
You cannot output to L+R+C+sub because that would require REW to output to three channels, which it cannot do.
And finally, it is your choice whether you output to L+R+sub, or C+sub. However, as explained a number of times before, mono bass is more likely to appear in the center channel, that's why it is important. That is not to say that measuring L+R+sub is not also important. Feel free to take as many measurements as you want, as long as you analyze them in the proper perspective.
Has this made it any clearer for you?