Calibration of outboard gear and DAW

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leegodden

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Hi

I know there are lots of threads on the subject of calibrating your recording equipment, but I would like to describe my setup and ask for some opinions.
I have a mic pre, going to a Focusrite sapphire pro 40 going into Pro tools and outputting to an M series Soundcraft analogue mixer.

Would I be correct in thinking that a simple way to calibrate all this would be as follows. Generate a test tone that goes into the mic pre, set the input of the mic pre to optimum level (ie occasionally peaking), then set a similar input level on the Focusrite and Pro tools, and then finally the Mixer, that way all is operating at optimum level.

Lastly what would be the best and reliable equipment (low cost preferably) to generate the test tone, some kind of hardware or software tone generator? and what signal should I use, a sine 1Hz test tone?

Thanks

R
 
You might get a more technical answer from other users here, but I don't know if I'd go to all that trouble.

You have meters for the line inputs on the front of your interface, so just plug in your preamp and set up your mic.
If the gain knobs on the saffire have effect on the line inputs, find out where you should set it for unity.
For some units that'll be completely counter clockwise; On others, there'll be a 0db point marked.

On some units with mic/line combo, the gain knob doesn't effect line input. Ie. Line input completely bypasses any amplifiers.

Now play some music and adjust the standalone mic preamp gain until you signal looks healthy. Make sure it never peaks red.

As far as I know, that should be fine.

The only thing you can really calibrate is whether the line input is expecting -10 or +4, and you just match that to whatever your preamp outputs.
If you do go down a more scientific road, Pro Tools has a built in plugin called signal generator.
I think you'll find it under instruments or other in the plugin menus.
 
set the input of the mic pre to optimum level (ie occasionally peaking)
"Occasionally peaking" means you are SO far over the "optimum level" that the circuit is occasionally failing completely.

No signal at any time at any point in the chain at any point in the production process should ever be in the same ZIP code as "peaking."
 
"Occasionally peaking" means you are SO far over the "optimum level" that the circuit is occasionally failing completely.

No signal at any time at any point in the chain at any point in the production process should ever be in the same ZIP code as "peaking."

John....not to segue the thread....but are you refering to the analog or digital gear?

I have an analog pre, and the recommended input operating levels are for peaks of +6 to +9 dB.
 
I'm referring to clip lights, I guess (as the post I quoted really wasn't clear).

The +6 to +9dB peaks makes perfect sense on the analog side (that's how we used to hit tape too).
 
I'm not sure OP is actually talking about calibrating, vs making sure levels match up. I think by calibrating, you'd be adjusting pots somewhere so that, e.g. 0VU on some particular piece of gear was .316v.

I'd think OP is on the correct path, send a test tone from (sound card/synth/whatever he has available) 1kHz seems adequate and set 0VU = 0VU = 0VU throughout his signal chain. I don't think a steady tone should "occasionally peak" though, it should be steady.

For the mic pre though, either op's going to have to attenuate a signal to 'mic level' or actually mic something (like an amp with a synth plugged in) with a tone. In that case, I suppose worst case absent a tone source like a synth, mic your hi-fi speaker while tuned to a non-existent FM station so that you're using essentially white noise?
 
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