Strange routing issue (stereo/mono?)

[blackjamParticipant]

Hello! This morning I had a first SQ5 nightmare situation in our church (all was super-smooth since we installed the SQ4 in April 2021).

For some reason, the console is not able to route mono sources to stereo buses and vice versa. Example:

– mic on input channel is not routed to LR, not routed to stereo Aux (live stream), not routed to stereo Aux (subs), but IS ROUTED to mono Aux used for stage monitors..
– stereo input from USB (playback) IS routed to LR and all the stereo Auxes

I know the console quite well and checked all the settings. I am pretty sure there is no operator error. In LR bus, I disabled all processing to eliminate insert FX errors, etc. No help.

The console was running 1.5.3. After the problem, I flashed 1.5.4, but no change. Turning off/on does not help. The UI on display works fine, there is no visible issue. Just when I route mono channel into LR, there is nothing. No blinking signal LED, no sound in headphones, no signal on Meters.

Unfortunately I don’t have the default scene saved, so I did not try scene reload or full console reset. Do you have any suggestions?
Thanks in advance.

Jakub

[Mike CParticipant]

So that mean you more or less have no inputs working on the mixer!

Is you LR main mix router directly to a set of outs or do you go through a matrix for the output?

For a quick visual routing check have you put the mixer in the LR mix mode and pressed the assign button on the Left hand side of the mixer, when pressing that button
all the channel SEL lights will light on the channels assigned to the mix that is selected.

You then can assign or unassign channels from mixes by holding the assign button and channel select buttons.

[Mike CParticipant]

Another thought……are the stereo mixes that are not working all POST fade mixes? LR is always post fade.

I’m assuming the mono stage monitor mixers are PRE fade.

By chance are the mono input channels assigned to a DCA group or groups and the DCA’s
are turned down.

Check the other layers for a DCA fader or look at the DCA menu.

[blackjamParticipant]

Thanks for the ideas.

Physically, I run LR to 3 matrix outputs to feed 3 venue zones (main hall, balcony, foyer). But my problem is right at the LR stage – I dont even hear the signal when I explicitly PAFL the LR bus.

I use 2 DCA groups and I checked they are not muted or level-zeroed… Also, I have checked the channel assignments, all is OK, on routing screen I see the pink bars responding with size to the fader level as usual.

Personally, I think I have entered into some strange sw bug, which prevents the stereo/mono conversion in the internal engine.

I can hear all channels in PAFL, but when I assign mono channel to LR, I hear nothing. The same channel routed to mono Aux 1 plays fine. When I route it to stereo Aux 9, I hear nothing. It is totally strange.

[KeithJ A&HModerator]

@blackjam

Well this is fascinating, could you please send a copy of your show to us using https://support.allen-heath.com
Then (as you’ll now have a backup) please try a hard reset and test again to rule out any firmware/setting related issue.

Thanks,
Keith.

[blackjamParticipant]

OK, tomorrow I will get the show cfg and send to support. I will also try the reset to see if it helps..

jakub

[Mike CParticipant]

Just for some thing to try…maybe un-assign and then re-assign a channel to the
main LR and see what happens.

what happens if you pan a channel to hard left or right, I thinking maybe some
wild phase cancellation thing going on, I know that’s a really way out there idea!

You said when you PAFL a stereo mix you hear nothing at all as in no trace at all
of any audio?

Going back to the beginning, the mixer worked fine on day and the next time
it was turned on the problem was there right from the start?

[blackjamParticipant]

Latest news: I have stored the show file and will submit it to support in few minutes.

How it behaves:

After hard reset, console is OK. When I plug mic to onboard input, it is routed to LR without problem.

When I load my show file, the problem is back. I hope the support will be able to find out what is wrong…

[blackjamParticipant]

Dear colleagues,

my issue has been resolved with perfect and professional assistance of A&H support (thanks Keith!).

It was really a DCA hidden on unused fader layer, which I completely missed and during the stress situation repeatedly skipped 😉

So, a big lesson learned….

Best regards from Prague
Jakub

[ScottParticipant]

This is one of the “tests” that I perform when training someone. I assign a channel to a DCA, then turn the DCA all the way down, then remove it completely from the surface. I let them troubleshoot and try to find why they aren’t getting audio from the channel. This is a good test because it does happen in the wild at times, and can be very stressful if you don’t think of this.

[KeithJ A&HModerator]

Good test. We’ve all done it!!

[Author]

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