Limiting for Streaming/Broadcast

[pfriggeParticipant]

For streaming our church services we have the following setup:
All inputs are routed into a mix bus from which our stream is fed (most inputs first go through groups with additional compression). On the mix bus we have a muliband compressor (insert) and the compressor section is configured as limiter (mode: peak, ratio: infinity, attack: minimum of 30us, threshold: 12db). So our limiter threshold is 6db below the absolute limit of 18db which corresponds to 0dbFS, right?
The limiter is only for extreme peaks, so it keeps mostly inactive and limits only occasionally (probably 4db compression max). However the peak/clip light of the mix bus flashes occasionally.

Is this because the compressor/limiter is not a true peak limiter (brickwall limiter) and therefore some peaks are coming through before the limiter is reacting? Or is there something else going on? I thought the 6db headroom would be plenty even if some peaks would pass.

Any solutions for this other than mixing even lower?
I know we could process the mix on a computer with a true peak limiter, but we would like to do it without additional hardware.

[KeithJ A&HModerator]

Hey @pfrigge,

All our digital consoles use multi-point peak detection.
So the ‘Pk’ LED’s on each channel strip (including the master strip) will indicate whenever there is a peak anywhere in the signal path of that channel.
Also, the layer keys will illuminate red if there is a peak on any channel strip on that layer.
So…
You could see a layer key flashing red, go to that layer, see a channel Pk LED flashing, go to that channel and find that you are peaking post-gate, even though you’ve made EQ cuts or added compression that mean the channel isn’t peaking at the end of it’s processing.

Hopefully this explains it, and you find that you peaking elsewhere in the channel (and can fix it!).

Thanks,
Keith.

[pfriggeParticipant]

Hey Keith,

thanks for your super fast response!
If I get you correctly the problem could be that the signal is peaking pre limiter (which indeed is quite likely – I’m not used to this problem from mixing in a DAW where I normally set the threshold just below 0dbFS an increase input gain until hitting the threshold). So would the solution be to mix lower (adjust threshold accordingly) and to increase the output level after the limiter(/compressor) using the output gain?

Thanks,
Pascal

[SteffenRParticipant]

Hi Pascal

the desks with the XCVI core should have enough headroom
so it should be no problem to clip shortly before the limiter

Steffen

[pfriggeParticipant]

Hi Steffen,

although I wasn’t quite shure I expected the headroom to be sufficient. Nonetheless I don’t want the peak light to flash because then I will always ignore it, even if it might be clipping after the limiter (because someone increased the output gain or what so ever). We are mixing with several engineers on the same board, so things must be as intuitive as possible.
Good to know anyway, thank you!

Pascal

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