Setting input levels on mixer with pre-gain vs output level on your equipment

[dqmgrs2025]

This might seem like a basic question but one I've been pondering over.

Obviously, you use the input gain on a mixer channel to set input levels to an appropriate level without clipping. However, the output level of your equipment going into that channel also influences the input levels on the channel.

I know it's generally acccepted practice to set mixer faders to unity point when setting input levels. However, is there any accepted optimum output level to set your equipment at? So you might have a guitar amp modeller, a keyboard or whatever connected to your mixer channels. The greater the output level on these, the less input gain you'll need on the mixer channels.

I generally set the output levels on my equipment such as guitar amp modellers, loopers, etc at about the 12 o'clock position on the output knob, then adjust the input gain at the mixer. However, I'm wondering if this is correct and if I'm losing out on channel gain and output volume through the PA by not setting the output levels of my equipment higher than 12 o'clock.

If I turn the output levels past 12 o'clock, this will result in more gain and volume going into the mixer and PA speakers, of course. If the output levels of the musical gear is not set high enough, you'd have to then turn your PA speakers up higher to compensate, possibly resulting in more hiss and background noise and in some cases not enough SPL for the venue, so obviously best to optimise levels going into the mixer channels in the first place.

However, if you turn the output level of musical gear up before the mixer channel, you'll therefore have to have lower input gain at the mxier, so wouldn't it just even out anyway? So would there really be any difference in the overall output level coming through your PA speakers if you have, for example, a guitar modeller output at 12 o'clock vs say 3 o'clock, because at the 3 o'clock positon you'd set the input gain lower on your mixer to compensate.....so ultimately, if your mixer channels peak at the same levels regardless of whether your amp modeller output is at 12 o'clock vs 3 o'clock (with lower input gain on mixer), does it ultimately make any difference to the overall sound and volume?

How much output level on your musical equipment is 'too much'? I mean, I would assume you would not want the output level set to full, for example.

Also, a guy who owns a local rehearsal/recording studio said that it's best not to have negative input gain on your mixer channels (e.g. the XR18 I use)....so if you see it's at a negative value, you should lower the output level on your equipment first so you no longer have to have negative gain levels on the mixer. I don't know if this really matters, but I thought it was worth mentioning.

Perhaps I'm just over-thinking this. Maybe ultimately output levels don't matter too much (as long as they're not too low or too high), as long as there's no clipping on the mixer channels or your PA speakers?

[Hugh Robjohns]

You really are over-thinking this.

Adjusting input and output levels is always about optimising the signal level to sit comfortably between the noise floor and the clipping level, and you would usually also want to retain some ability to raise or lower the level to accommodate performance variations.

So, for example, I wouldn't typically set a keyboard output to full level because it might be helpful to be able to tweak the level slightly up/down during a performance.

So I'd typically set a keyboard or guitar processor somewhere between 12 and 2 o'clock on a rotary control.

I would then adjust the mixer or interface input gain control to set a suitable level through the mixer/interface.

And if a live sound situation, the level going to the PA is controlled by the mixer output and/or the PA amp/speaker inputs.

[AlecSp]

You really are over-thinking this.

This!

Adjusting input and output levels is always about optimising the signal level to sit comfortably between the noise floor and the clipping level, and you would usually also want to retain some ability to raise or lower the level to accommodate performance variations.

And this is why, in practice, it depends.

The other thing I'd mention, that a lot of people struggle with, is to remember that gain is gain, wherever you add it.

[dqmgrs2025]

You really are over-thinking this.

Thanks for the reply, yes I probably am over-thinking this but it makes more sense now. As the other reply here essentially said, 'gain is gain no matter where it's added'.

Adjusting input and output levels is always about optimising the signal level to sit comfortably between the noise floor and the clipping level, and you would usually also want to retain some ability to raise or lower the level to accommodate performance variations.

So, for example, I wouldn't typically set a keyboard output to full level because it might be helpful to be able to tweak the level slightly up/down during a performance.

So I'd typically set a keyboard or guitar processor somewhere between 12 and 2 o'clock on a rotary control.

Yes that makes sense, so you'd need to leave a decent amount of headroom on your mixer channels if you wanted to tweak instruments up/down during a performance by using their output level control. Though I suppose the standard practice in setting input levels with digital mixers is to leave plenty of headroom anyway when you set your peak and average levels, so that would work.

I would then adjust the mixer or interface input gain control to set a suitable level through the mixer/interface.

And if a live sound situation, the level going to the PA is controlled by the mixer output and/or the PA amp/speaker inputs.

The thing I've noticed about a lot of digital mixers (such as the XR18) is the lack of any proper meters on the channels, i.e. meters with actual number readings on them. When you control them via software or an app, you usually just get a level range consisting of 3 colours (green, yellow and red) as your meter readings. This makes it harder to set input levels optimally as you can't see the actual readings (peak and average). It's easier to set if your mixer is being used for recording into your DAW, as you can check the levels on your DAW channel meters.

Well, to be fair, apps like Mixing Station do have a separate metering section, which displays the dBFS meters with numbers on them, however it would be nice to have these on each mixer channel themselves, rather than just the 3 colour ranges. I wonder if there's a reason for this, or if it's just standard practice across most digital mixers used for live sound.

[Arpangel]

No real need for channel meters, just solo and use your main meters.
As long as your input signal is within a certain level, you really don’t need to worry about any of this, when I’m mixing or playing levels can go all over the place, as effects get turned on and off, I just make sure I’ve got enough headroom to accommodate these things.

[AlecSp]

The thing I've noticed about a lot of digital mixers (such as the XR18) is the lack of any proper meters on the channels, i.e. meters with actual number readings on them. When you control them via software or an app, you usually just get a level range consisting of 3 colours (green, yellow and red) as your meter readings. This makes it harder to set input levels optimally as you can't see the actual readings (peak and average). It's easier to set if your mixer is being used for recording into your DAW, as you can check the levels on your DAW channel meters.

Well, to be fair, apps like Mixing Station do have a separate metering section, which displays the dBFS meters with numbers on them, however it would be nice to have these on each mixer channel themselves, rather than just the 3 colour ranges. I wonder if there's a reason for this, or if it's just standard practice across most digital mixers used for live sound.

Not sure what you're talking about. X-Air doesn't have meters, they're implemented in whatever controlling software you're using.

Both X-Air Edit and Mixing Station give meters with legends throughout.

[Philbo King]

Many mixers have a PFL (prefader level) button on each channel which feeds directly to the main meter. The input gain is intended to be set during sound check to get a decent level without clipping.

The thing about tweaking around on the input attenuator/input gain during a show is that it also affects Aux send levels for that channel. If the Aux is feeding stage wedges or IEMs, you can suddenly find yourself wondering where the feedback squeal is coming from, or in the case of IEMs, looking for a new job after frying the performers hearing.

[dqmgrs2025]

Not sure what you're talking about. X-Air doesn't have meters, they're implemented in whatever controlling software you're using.

Both X-Air Edit and Mixing Station give meters with legends throughout.

Actually, I just realised the channels on the XR18 in Mixing Station DO have numbers, and I think it's db, not dBFS. Because unity point on the channels = O db, not dBFS. There is also a separate metering tab.

[AlecSp]

Actually, I just realised the channels on the XR18 in Mixing Station DO have numbers, and I think it's db, not dBFS. Because unity point on the channels = O db, not dBFS. There is also a separate metering tab.

The meters by the faders on the mixing layer don't have labels - and thank goodness, as it would clutter that screen. You're confusing the fader labels with metering labels.

The meters in channel view and on the meters page do have labels.

Either way, it's really not that worth obsessing about. Whenever has a precise metered value really been of importance?

[Hugh Robjohns]

Whenever has a precise metered value really been of importance?

Mastering and system calibration, for two examples...

...but in the context of mixing, youre right: the metered level isn't particularly important provided the signal has adequate headroom and is well above the noisefloor. What it sounds like is far important than what the meters are doing.

[dqmgrs2025]

Actually, I just realised the channels on the XR18 in Mixing Station DO have numbers, and I think it's db, not dBFS. Because unity point on the channels = O db, not dBFS. There is also a separate metering tab.

The meters by the faders on the mixing layer don't have labels - and thank goodness, as it would clutter that screen. You're confusing the fader labels with metering labels.

The meters in channel view and on the meters page do have labels.

Either way, it's really not that worth obsessing about. Whenever has a precise metered value really been of importance?

What do you mean by 'labels'? The channel meters have numbers. But by 'labelsl, do you mean db, dBFS etc?