LP8- adjust digital input level?

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Level 1

8 points

LP8- adjust digital input level?

Is there any way to internally adjust the input level coming from my interface via firewire?

Long version- recording live music, from the line level analog record outs from the main mixer (usually RCA or 1/4"), into a Focusrite audio interface (multi-tracked with some mics), and then connected digitally via firewire to my MacBook Pro. Problem is, that with most of the shows I record, there's no actual sound person and the main mixer is left of to the artist performing, and they often times won't hesitate to push the levels well into the red.

That's bad enough, but I might be able to work some magic if I could pull back the level in my laptop and at least avoid the digital distortion internally. Is there a way to do that or am I stuck with the output level of that main mixer?

Posted on Aug 18, 2011 4:22 PM

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Answer 1

Pancenter

Level 6

14,644 points

Aug 18, 2011 4:37 PM in response to Brian Albers

You're recording analog out into the Focusrite? If you can't adjust the mixer the best you can do is keep the input levels of the Focusrite at an acceptable level. Where are the input levels of the Focusrite adjusted from, software or hardware?

The FireWire interface is a simple transference of data, reducing the incoming in the Macbook (Logic can do this using the Input object(s)) won't make any difference if the distortion is at the Focusrite analog input stage.

pancenter

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Answer 2

Brian Albers Author

Level 1

8 points

Aug 18, 2011 4:51 PM in response to Pancenter

Ya, unfortunately I don't ever have any control over the main mixer output levels. As far as I know, I can't control the digital output levels going from the Focusrite to the laptop. So I'm stuck with whatever they give me. I'm just hoping there's a way that I can minimize the damage using some setting or control in Logic, but I don't know if that's possible.

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Answer 3

Pancenter

Level 6

14,644 points

Aug 18, 2011 5:49 PM in response to Brian Albers

Brian Albers wrote:

Ya, unfortunately I don't ever have any control over the main mixer output levels. As far as I know, I can't control the digital output levels going from the Focusrite to the laptop. So I'm stuck with whatever they give me. I'm just hoping there's a way that I can minimize the damage using some setting or control in Logic, but I don't know if that's possible.

But you do have control over the analog Input levels of the Focusrite, correct? While you may not have control over the Mixer's output you can reduce the recording levels of the Focusrite.

pancenter-

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Answer 4

Brian Albers Author

Level 1

8 points

Aug 18, 2011 5:56 PM in response to Pancenter

Nope, no control. I've got the Saffire Pro 24, just the basic model not the one with all the DSP capabilities. As far as I know, the line level inputs are input -> firewire out. The mic inputs on the front have their own gain controls, but none of the other inputs have those controls.

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Answer 5

Pancenter

Level 6

14,644 points

Aug 18, 2011 6:10 PM in response to Brian Albers

There's no input control for Analog 3 & 4 in the Saffire "MixControl" software applet?

There's also High/Low gain adjustments for analog Inputs 3 & 4 in Mixcontrol.

pancenter-

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Answer 6

Brian Albers Author

Level 1

8 points

Oct 17, 2011 3:13 PM in response to Pancenter

OK, so I was unaware of the Saffire MixControl internal mixer before all this. So I installed it and have been playing around with it, and ya know what? It still doesn't fix my problem, because I still have no way of attenuating the incoming line level signal into the 1/4" inputs on the back panel. Well, no way outside of that high/low gain option you mentioned, but even on low gain, there's still too much level, so I really need to find a way to somehow back it off.

Everything else about the MixControl is working fine, but I've done tests where I put every fader in the signal path (inputs #3 and 4 in MixControl where the line level inputs are plugged into the Pro 24, the master fader in the MixControl, the channel strip in Logic that is recording 3 and 4, as well as the master fader in Logic) on -∞, and none of it has any affect on the signal. The faders in Logic are output controls, right?, so you wouldn't expect those to change the input level anyway.

I sent in my whole scenario to the Focusrite help desk but haven't gotten a response yet, so in the meantime I thought I'd try back here again.

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Answer 7

Pancenter

Level 6

14,644 points

Oct 17, 2011 4:02 PM in response to Brian Albers

Brian Albers wrote:

It still doesn't fix my problem, because I still have no way of attenuating the incoming line level signal into the 1/4" inputs on the back panel. Well, no way outside of that high/low gain option you mentioned, but even on low gain, there's still too much level, so I really need to find a way to somehow back it off.

Your first sentence says it all!

You're distorting the inputs of the Focusrite. There is nothing you can do after that fact if the input circuitry of the recording device is fed too hot a signal. if the high/low gain switch doesn't provide enough attenuation then you will need some additional hardware between the mixer's line out and the focusrite input. That must be a ridiculously hot signal coming out of the mixer.

With the exception of the high/low gain switch, everything you've mentioned is after the fact.

If the distortion is happening internal to the mixer then you are out of luck.

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Answer 8

Brian Albers Author

Level 1

8 points

Oct 17, 2011 4:45 PM in response to Pancenter

Well, like I said, I don't have control over the level of those inputs. And be that as it may, I was really hoping that there'd be some way to adjust the input level (no matter if it's too high or too low on anything in between) in Logic when recording from a digital source. Hopefully the Focusrite people get back to me with a way to that with the MixControl mixer.

But thanks for your help, Pancenter.

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Answer 9

Pancenter

Level 6

14,644 points

Oct 17, 2011 5:05 PM in response to Brian Albers

Brian Albers wrote:

Well, like I said, I don't have control over the level of those inputs. And be that as it may, I was really hoping that there'd be some way to adjust the input level (no matter if it's too high or too low on anything in between) in Logic when recording from a digital source.

But thanks for your help, Pancenter.

I don't think you understand gain staging... the distortion is happening way before Logic so it doesn't matter what levels you set for recording in Logic, you would still be recording a distorted signal because it's happening at the Line In - A/D convertors.

Basic audio 101

If the signal coming into any recording device is too hot for the input stage to handle, it doesn't matter the recording level because it's the circuitry (whether analog or digital) that's distorting.

I honestly think your only option if to use an attenuating device between the mixer and Focusrite.

I'll be curious to hear what Focusrite says.

pancenter-

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