Main left and right out of phase

[dmshan12]

Hi all, did a gig last night using my QU 16-SB. Venue had in house PA so I was sending my main L + R to their desk. Venue sound guy told me it sounded like my L + R outputs were out of phase with one another so he was getting plenty of line signal but it seemed volume wise they were almost cancelling eachother out. I haven’t ever encountered this issue when running through my speakers nor when I’ve plugged into other in house systems. Apologies for the lack of specificity as I’m not sure what specific cabling they used to run into their desk or what desk they were using, they ended up cutting our sound check time down drastically after we’d arrived so was all a bit manic. Just looking for any general suggestions of what could cause phasing issues for the main L + R outputs.

[KeithJ A&H]

@dmshan12

The first things to check would be cables and connections.
Then to rule out anything software related:

1. Make a backup of your show
2. Reinstall the latest version of firmware using a fresh download – https://www.allen-heath.com/qu-series/qu-sb/#software
3. Carry out a hard/factory reset – https://www.allen-heath.com/media/Qu-SB-Getting-Started-Guide-AP10287_2.pdf#page=19&zoom=auto,-274,412
4. Test the outputs (e.g. using a Sine from the SigGen)
5. Recall your show
6. Test the outputs again

If you still believe there is an issue, please contact us directly via support.allen-heath.com and we’ll look into this further with you 🙂

Thanks,
Keith.

[Mike C]

Yea I would look at the cables and connections starting with what was plugged into the mixer.
It could even had been one of the input channels had polarity set to invert.

A quick fix would have been to pan everything to one side on your mixer and run mono.

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