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Common problem, low input recording levels from mixer...

Posted: Mon Apr 23, 2018 9:14 pm
by arretx
I'm not sure how to fix this problem. We run a QU32 Allen & Heath mixer into our iMac and thus Ableton Live.

When we record someone speaking on a wireless headset from the stage, the levels, despite the input slider on the channel strip in Ableton, are low. We find ourselves having to boost the recording before we export it from Ableton Live.

If we increase the input on the the QU32 mixer, naturally the house level goes up as well, which we don't want. I'm not sure how to adjust the signal that's going from the QU32 (which is basically a big fat fancy sound interface) to the iMac without affecting the mains.

Ideas?

Re: Common problem, low input recording levels from mixer...

Posted: Tue Apr 24, 2018 6:59 am
by Stromkraft
arretx wrote: When we record someone speaking on a wireless headset from the stage, the levels, despite the input slider on the channel strip in Ableton, are low.
Define "Low". Too low for what? In comparison with what?

Re: Common problem, low input recording levels from mixer...

Posted: Tue Apr 24, 2018 10:40 pm
by fishmonkey
arretx wrote:I'm not sure how to fix this problem. We run a QU32 Allen & Heath mixer into our iMac and thus Ableton Live.

When we record someone speaking on a wireless headset from the stage, the levels, despite the input slider on the channel strip in Ableton, are low. We find ourselves having to boost the recording before we export it from Ableton Live.

If we increase the input on the the QU32 mixer, naturally the house level goes up as well, which we don't want. I'm not sure how to adjust the signal that's going from the QU32 (which is basically a big fat fancy sound interface) to the iMac without affecting the mains.

Ideas?
do you have a healthy channel level on the desk itself? if the level at the desk is also low, then your overall gain staging could be improved.

also, are you trying to record a post-fader version of the audio? more details about your setup and routing would be helpful...

Re: Common problem, low input recording levels from mixer...

Posted: Wed Apr 25, 2018 5:12 pm
by Shift Gorden
Do you have an audio interface plugged into the iMac? If so, does it have a phantom power toggle?

Re: Common problem, low input recording levels from mixer...

Posted: Thu Apr 26, 2018 4:06 am
by fishmonkey
the Allen & Heath Qu mixers have built-in audio interfaces...

Re: Common problem, low input recording levels from mixer...

Posted: Fri Apr 27, 2018 4:41 am
by arretx
Clarification on the situation.

The QU-32 basically *is* a glorified sound module. When attached to the iMac, it behaves just like the Scarlett, or any other external sound interface by disabling the software input and output mixing controls and handing them over to the software the comes with the device. The QU drivers work with the mac for MIDI daw control, etc. etc.

There is a setting on the QU-32 that I didn't know about that takes the signal just before it gets processed and sends it "Directly Out."

It turns out that between the wireless transmitter and receiver, and the gain on the QU-32, the levels weren't set high enough despite the ability to "hear" the signal out of the DSP through the mains just fine.

So, what needs to happen now, after testing, is the Direct Out for that channel, or any other channel that's being recorded, needs to have the trim increased, and the gain needs to be higher on the channel on the QU-32.

With the right settings and limited EQ that we can manage in the environment we're in, I can get the meter in Ableton to read at about -18db where before it was way, way below that.

Re: Common problem, low input recording levels from mixer...

Posted: Fri Apr 27, 2018 9:11 am
by fishmonkey
yep, that's what i thought might be happening.

if the mains are at the desired volume, but you are having to run your mixer channels at low levels, then the gain structure is probably not the best. i suggest that you turn the gain on the main amps down so that you can run your mixer channels at healthier levels...

Re: Common problem, low input recording levels from mixer...

Posted: Fri Apr 27, 2018 2:39 pm
by arretx
We have one other point of adjustment. The main outs from the QU-32 feed into a QSC Rave 522UA DSP which is only adjustable by rocket scientists with a Windows workstation ;).

What's the correct order of operations, assuming we just installed the entire system and haven't touched any levels yet?

Am I close or way off base?

1. Set the gains on the mixer and test the input levels.
2. Send the signal over the mains to the DSP and set the levels in the DSP.
3. Send the DSP signal to the active mains and adjust the gains on the mains.
4. EQ each instrument and voice.

Re: Common problem, low input recording levels from mixer...

Posted: Sun Apr 29, 2018 2:17 am
by fishmonkey
arretx wrote:We have one other point of adjustment. The main outs from the QU-32 feed into a QSC Rave 522UA DSP which is only adjustable by rocket scientists with a Windows workstation ;).

What's the correct order of operations, assuming we just installed the entire system and haven't touched any levels yet?

Am I close or way off base?

1. Set the gains on the mixer and test the input levels.
2. Send the signal over the mains to the DSP and set the levels in the DSP.
3. Send the DSP signal to the active mains and adjust the gains on the mains.
4. EQ each instrument and voice.
yep, that's pretty much the right order. essentially you want to build your gain structure from the front end back to the main amps.

if you set the main amps first, and they are running with way too much gain, then you are forced to use low gain at the mixing desk. this can be dealt with by running low channel input gains, which potentially increases noise (and can cause issues with using the signal elsewhere, as you have found). alternatively, you can run the input gains at reasonable levels, but you are then forced to run either your channel faders at low levels (which makes mixing harder), or run with your master faders at low levels. things also get more complicated if you have multiple amps and speaker sets and stage monitoring.

setting up your gain structure carefully makes everything smoother...