Qu-SB Outputs out of phase?

[hobsound]

Odd problem has happened twice with my Qu-SB.
There are times when I am only running a single sub with 2 tops.
Normally what I do (with my Qu-16) is run Main L and R into the sub, which then feeds the L and R tops after the crossover.
When I do this with the Qu-SB, I get practically no output from the sub. If I pull one of the inputs (either L or R), I get sound back from the sub.
To me, that sounds like one of the outputs from the SB is out of phase with the other.
I will open a support ticket with A&H but thought I’d post in case someone has any idea what is going on.
Thanks in advance-

[Chris93]

It would be basically impossible for a PCB mounted XLR connector to be wired incorrectly. The traces on the board line up with the pins of the connector and there would be no way for them to get crossed. The connectors will look something like this inside:

https://www.eijndhoven.net/jos/relaixedsmd/fotos/mounted-PCB-1280.jpg

Have you checked your cabling? Is it possible that you have the polarity inverted on one side of a stereo input in the Qu SB app?

Chris

[hobsound]

Chris,
Cable issue was the first thing I thought of, but different cables both times this happened.
Good question about the Qu-PAD app, will check that today.
Thanks

[GCumbee]

Where did you get an SB? I thought they were not shipping yet.

[hobsound]

Got it at B&H a few weeks ago.
I’ve seen some stock here and there. Really want the rack kit so I can get it off the floor.
But the gigs I’ve done so far, I love it.
And I can load scenes from my Qu-16 which is cool. Also, don’t have to eat an Aux for FX3 and FX4 anymore.
Just need to figure out this phase issue with the single sub.

[GCumbee]

Weird. I’m a dealer and they told me not available. I’m having trouble getting many things right now. No stage boxes available. Supposed to get shipments this week.

[GCumbee]

Try feeding the same thing from mix 5-6. What happens when you do that? If ok then there has to be something flipped. With a single sub I would think it better to feed LR to the mains then feed the sub with a mix like 9. Just send the sub LF instruments.

[Andreas]

Simple test could be to feed three (3) mixes from a single mono channel. Plug the PA cables to Mix1&Mix2. If the issue persists, use Mix2&Mix3. If the issue persists, use Mix1&3. If the issue still persists, its the cables.
If that’s all ok, test Mix1&L and then Mix1&R (using the same mono channel to feed L&R).
…but I somehow doubt that A&H made that kind of mistake in hardware…

[hobsound]

I certainly could, I just like the ease of running a single 2-pair cable (L&R) to the sub and using the internal crossover to the tops.
What I did last night was plug an XLR splitter cable into the sub and just ran off Main L from the SB.
I will figure out what is going on!

[Allen & Heath Product Support]

Hi Rob,

Thanks for bringing this to our attention. After testing a few of our units in-house we can confirm that this is a bug.

Our software guys are working on this as I type and we will be releasing a firmware update ASAP to address this issue.

Apologies for any inconvenience
Mike

[GCumbee]

I am assuming this is just an SB issue?

[Anonymous]

Be good to know exactly what the bug is for those who need to work around it fast.

[hobsound]

From my side of things, only seems to be on the Qu-SB, not on my Qu-16 or Qu-24.
And only when I am running Main L and Main R into the same sub.
When I ran 2 subs, didn’t seem to be an issue.
SO for now I will run one side of the Main only and use a splitter to feed both sides of the sub.

[David Haughton]

Hi all, I can confirm this issue is with Qu-SB only and we will be releasing a fix imminently.
Thanks.
Harry.

[Anonymous]

Cheers – I hadn’t noticed on my QU16 with subs separated – so I was pretty confident that it wasn’t a fleet wide issue.

[Author]

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