Hi,
I got strong transient (big bang) on local outputs when I switch off SQ5.
When I mute everything, it is the same.
The DX168 stagebox handles this situation well.
Are there any possibilities to solve this issue?
BR, Gabor
turn off the PA first… always…
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Hi SteffenR,
Yes, it is a very simple solution, and I heard about it several years ago. 
Unfortunately, it is not always so simple (power outage, installations, etc.) and I ask about the reason, why it is so rough on this mixer, and why not on DX168? I hope you can understand my point of view. I am very satisfied with DX behavior and I suggest to apply a similar solution in mixers.
It could help with lots of situations, where the customers are not professional users, I could use one switch to switch off the system, etc.
BR, Gábor
maybe you should search the forum again
we discussed this already many times
use a proper power sequencer to turn everything on/off
as a bonus you could get one with transient spikes protection too
For just about any install system in a multi use facility a power sequencing system
is the only way to go. You can get a master unit say in the sound booth and connect it to
remote units to turn on and off outlying pieces of equipment all with the flip of a switch or turn of a key.
The mixer still should be put into the power down mode before shutting down the system.
Even with a sequencing system some people try to make it harder then it needs to be…I installed a smaller sound system, all components in a single wall mount rack with a keyed power sequencer.
Go back to the system a year or so later to add some additional equipment, find the sequencer all powered on but the equipment that has front panel power switches all shut off, they said they did not like waiting for the equipment to power up or power down.
At most in that system the sequence cycle took 30 secs.
15 years ago i bought a EPD 420VS Power Distribution/Sequencer. It has 4 20 amp outlets and accommodates 100 amps input directly from the power panel. My KV2 ES FOH system requires 20 amps for each stack, My three EX10 wedges use the third 20 amp output and all of the processing and video gear is the last 20 amp shut down. (I prefer to keep aLL lighting power needs on a totally different panel if and when possible: however never on the Audio/Video circuit) I have never had any problems like the OP has raised. Unfortunately ETA systems, The small high grade company that manufactured the EDP unit, sold out to a bigger company that discontinued the EDP 420S: If you can find one on the secondary market buy it if you can get where you need to go with 4 clean 20 amp outlets and a bullet proof sequencer. This type of device is a “NO BRAINER” for everyone that has a substantial investment in Audio/Video gear.
HUGH
As I mentioned the DX168 stage box handles this situation much better.
What is more the Behringer X32 handles switch off much better than SQ.
I understand that this problem can’t be solved on already purchased mixers, but the AH engineers should consider this in the future.
Yes, I can handle it, but it is not fit for this cool mixer.
you still need a power sequencer else you run the risk of causing big problems
AH is doing just fine. the problem is not all users are experienced and knowledgeable enough to do things properly.
if you know what you are doing and never make mistakes then just sequence all the powers ons offs properly yourself
else buy a sequencer to do it for you
You still need a power sequencing system in place or…everyone needs to understand to turn on front of house equipment first, mixer, wireless mics, other input sources and then turn on the the power amps and or any powered speakers.
Turning the system off is just the opposite, power amp and of powered speakers first and then everything else.
Look up Furman power sequencing equipment.
I wanted to add that a power sequencing system needs to be installed properly with the sound system equipment connected to proper stages of the sequencer.
Are you doing the home screen shut-down procedure?
There is a huge difference in the staged processing that is prominent in the SQ desks and a high quality but relatively simple stage box that has no appreciable processing whatsoever. Always follow the SQ “power down protocol”. The first two steps power down the processing granting permission to push the power button to actually shut down the desk. This is a very important procedure to follow for several reasons: There will be no speaker “snap, crack, or pop” until the SQ is actually turned off. in the event you have a sequenced power module (like an ETA ECS3) the 3 second lapse between each shut down that is structured to be in reverse order of the turn on will turn off all connected devices automatically & flawlessly If you will follow the recommended protocol.
Hugh
https://community.allen-heath.com/forums/topic/noise-on-power-on-off
DX has build in relays on outputs.
But i do not understand why the developers saved is up in the SQ - so it has NO build in Relais… =(
greetings,
dd
discovert, that Avantis also has build in “Ready relays”
So SQ and Avantis will have different Output stages…
@A&H: are the D/A Converters the same or are in the SQ-Series the cheaper ones?
Yes this happens …
The GLD, (the last golden console) muted its outputs on the surface. No transients.
Used a QU one day, bang…
Discovered that the stage box (ar2412) also doesnt do this…
So i deliberatly patch all my outputs to speakers through the stage boxes.
At a festival once, packing up, old mate trying to help unplugs my FOH power feed so he can roll the lead up… Thank goodness for the GLD!
@allen and heath… Its gotta be a simple fix…please just fix it!
Yeah power down the right way they say…
They havent worked with students, volunteers etc.
@allen and heath… Its gotta be a simple fix….please just fix it!
It’s not a simple fix…
there would be a redesign of the output circuitry of the QU necessary
and this would significantly lift the price tag for an 12 year old console design
At a festival once, packing up, old mate trying to help unplugs my FOH power feed so he can roll the lead up…. Thank goodness for the GLD!
Old habit, if I’m at FOH with a desk I’ve brought, and there’s a bunch of people taking the show down, I start by yanking all the outputs from the desk.
To clarify, if one is using a stage box (AR2412, etc), connected to a mixer only via a dSnake (cat cable), then the power sequence stage box/mixer does not matter. What matters is any amps/speakers connected to the stagebox. Thus, you should power sequence the stagebox first, then amps. Off would be amps, then stage box. The mixer, if only connected via a network cable, is not a concern.
Is this true?
It’s the industry standard to power on speakers/amps last in the signal chain, and power them off first. This ensures there are no loud transients/bangs going through the PA due to powering on/off other devices. This isn’t a “suggested” practice. You should follow this 100% of the time.
Sure there are some devices that have protections build in to prevent these transients. However I would never assume that the equipment I’m using have those protections (if I am unfamiliar with the facility), or really even rely on them if I know they do because I am reinforcing bad techniques if I do.
Speakers/amps on last, and off first - always. It’s the industry standard for a reason.
Brian,
I do appreciate that and you are correct. But not everyone walks up to our board and does it correct every time. Its good to know what happens when they don’t.