Originally Posted by kwma01
I have been fighting an issue that has driven me crazy. My projector is fed with a vga signal from my HTPC. The receiver is connect to my HTPC via HDMI cable. When I turn off my TV to watch a movie on the projector my sound disappears because it was coming thru the HDMI cable.
I thought that I had a clean fix by using the optical line out from my HTPC and reassigning the digital audio input for the PC as OPT1. Unfortunately it seems as though the HDMI audio overrides the setting to use OPT1.
If I disconnect the HDMI cable I get sound (thru OPT1) when it is connected I get nothing (sound is disabled on HDMI on HTPC). Is this a firmware issue with the receiver or am I missing something?
I'm not sure I came across an official term for how Onkyo organizes
the inputs. Basically, Each of the source buttons, on the front of the receiver,
and the remote, represent a "virtual device". Each virtual device can have
multiple input sources, but only one of each type (HDMI, S-Video etc). Onkyo
assigns a priority to each type of input. HDMI is top priority, followed by Component,
VGA, S-VIDEO and Composite (see manual, page 22, "Signal Selection"). There
is a note about connecting sources to the PC virtual device, on the top of
page 20. I believe this same priority scheme holds true for audio inputs. In other
words, HDMI is top priority.
I am not 100% sure I'm following you. It sounds like powering off/on your TV/projector
causes your HTPC to choose a different monitor port, and thus stops routing audio over
HDMI to the receiver. Since the receiver has a priority scheme, it is still looking at
HDMI as the audio source, even though you have the optical cable connected from
your HTPC. If this is correct, you can probably get around the problem, by doing one
or more of the following:
1. Add a two port HDMI repeater to the output of the receiver. One output goes
to the TV, the other to the projector (assuming you have an HDMI port on your
projector). This will also allow you to get the OSD on your projector.
2. Assign the HTPC optical cable to a different "virtual device". Select this
device, when using the projector. This will defeat the priority scheme, as long
as no higher priority inputs are being driven on that virtual device.
3. On the HTPC, disable the HDMI port, when you want to use the projector.
This should fool the receiver into thinking it is not being driven.
4. Check your HTPC audio driver, to see if you have the option to always drive
audio on a given output (HDMI or optical). Setting up the HTPC to do monitor
cloning might also work (same exact display, on both "monitors"), since it "should"
then keep both monitors active, independent of which you are using.
5. Leave the TV on, select an undriven input, so screen is blank
6. Swap driving sources (assumes projector has HDMI). VGA to TV, optical SPDIF
to the receiver, HDMI through receiver to projector. When the projector is off,
the receiver "should" select the optical audio. When the projector is on,
it will override the optical input. Note, you will lose the OSD on the TV.