Hey,
I notice when using Out 1/2 on the output of the strip the volume of the preset is quite a bit louder than when I only send it to Out 1.
Both XLR out 1 and 2 are connected via XLR to TS to my 16 channel in-ear system, in which both “inputs” are set as mono channels as well, center panned.
Any idea as to why the volume would change that much?
Because two equal signals that are overlaying each other (summed to mono) will be louder than one signal alone (the waves amplify each other). That’s what you do when sending the same signal out of both outputs to your in ear system which is set to center both signals. If you only need mono than one output and one cable to your mixer is sufficient.
Thanks for the simple, yet extremely clear answer and solution!
The reason why I send 2 monos is because in my own patches XLR 1 is for guitar and XLR 2 is for bass.
But when testing out the default presets (which are set Out 1/2) I noticed they sounded way louder, even though the output meter was the same.
So when I applied the Out 1/2 to my preset I noticed the volume jump as well.
For some reason in my mind it went: same signal incoming on multichannel on 1 and 2 is just same signal strength as one of the channels on the output of the multichannel, instead of indeed the basic physics of added waves (and inverted waves in noise-cancelling techniques)… Like guitar on channel 1 won’t make bass on channel 2 louder, but it does indeed IF the waves are matching. You just “hear” it differently.
And especially as everything didn’t sound distorted whatsoever it never clicked…
So in short: thank you!
Sometimes our brains won’t see the most obvious / simple solution, unfortunately happens to me more often than I would like. 
keep in mind though that the QC doesn’t automatically sum to mono
Very true, this is a feature that has been requested for a long time, but unfortunately, it hasn’t made its way to the updates yet.
if you read this and you haven’t voted for it, go do it, we really need it!
But this isn’t the use case of the OP here. Both signals are mono, one guitar and one bass. As OP does not use stereo signals for his band setup I think he won’t utilize stereo signals at all 
If he wants to try out some stereo patches than you are right of course, good hint.
Let me preface with… I did not know this.
That said, would it be noticeable? (Aside from levels)
Scenario 1) stereo signal → stereo blocks → output 1
Scenario 2) mono signal → mono blocks → output 1
Scenario 3) stereo signal-> stereo blocks → out 1/2 st
Scenario 4) mono signal → stereo blocks-> out 1/2 st
Would there be a discernible difference between scenario 1 & 2? Or 3 &4? Lets assume source signal is a steady tone (simple piano).
Edit- ive done mono vs stereo experiments using logic and noticed no difference in sound when comparing hard panned L or R stereo to the panned L or R mono. Only when using stereo R & L combined does say a basic reverb come to life. Night and day.
Indeed, I’ve had built my setup with all mono blocks and effects, so not an issue there.
However I do agree that even if it would be a stereo rig, the fact that I output it (in the software, no cable detection) to only one output the QC should sum it to mono automatically!
If I understand your last sentence correctly, than that is already the case. If you have a stereo signal configured in the grid of the QC but set your output to a single output (output 1) than it will be summed to mono. If I’m not mistaken the feature others are asking for is, that if you have a double output set (eg output 1/2) but only one output connected to something, than the QC should detect this and sum to mono on the connected output, ignoring the set output configuration.
Physics sais if you add two identical signals together, as in you’re playing in mono, outputs 1/2 will be exactly 6dB louder than just output 1.
As you’re playing in mono you could add a gain block with +/-6dB and toggle that on/off to get to the same level again.
If you were to sum two completely uncorrelated signals, like guitar and bass, you’d only add 3dB.
If you’d be playing in stereo, that would be somewhere in between.
