Gain Staging Mistakes Part 1: Setting preamp gain

Gain staging is a hot topic, but it isn't anywhere near as difficult as people think it is. In this video we look at the first part of gain staging, which is setting the preamp gain. It's important to set the preamp gain low enough to allow good headroom, but not so low that there's too much noise.

Automated transcript

There are several aspects to gain stay tuned throughout the recording process here I'm going to concentrate on setting the preamp gain by the way it's easy gain staging is not the complicated issue that a lot of people would like to tell you that it is what I have here is a simple recording of a poem from an external sound source connected to the line input of my audio interface all I need to do is set the gain and watch the meter in my digital audio workstation which is Pro Tools but you can use any digital audio workstation software so I'll start with a setting that will work every time without fail I'm going to set the gain so that the signal Bob's up and down around the level of minus 18 DB FS that's 18 decibels below the maximum level that a WAV file can handle your digital audio workstation by the way can handle levels much higher than that internally also I'm going to keep an eye on where the peak level is in this case roundabout -10 DB FS it doesn't have to be exact you can go up to minus 6 if you like minus 6 would be about the highest you'd want to go and I'll explain why in a moment so here we go rubbing up and down roundabout minus 18 peaking roundabout minus 10 I wandered lonely as a cloud that floats on high or Dale and Hill when all at once I saw crowd a host of golden daffodils beside the lake beneath the trees fluttering and dancing in the breeze ok that sounds good the next question is how high can you go without getting into trouble well you can record all the way up to 0 DB FS as long as the red light at the top of the column doesn't come on here's an example I wandered lonely as a cloud that floats on high or day land Hill when all at once I saw a crowd a host of golden daffodils beside the lake beneath the trees fluttering and dancing in the breeze this sounds good but the problem is you've got absolutely no Headroom so if the person speaking or singing or the musician playing goes any louder it's going to clip and you'll get Distortion by keeping the peak level down it gives you Headroom so you don't have to worry about that red light coming on you don't want that red light coming on because that means you have clipping in your wav file and that means Distortion and it doesn't sound nice okay what does distortion sound like this time I've set the gain too high so you'll hear the signal going into clipping and you'll see the peak red light coming on I wandered lonely as a cloud that floats on high or day land hill when all at once I saw crowd a host of golden daffodils beside the lake beneath the trees fluttering and dancing in the breeze so now we know what's wrong with clipping and why it's good to leave Headroom so I'll just say once again bobbing up and down roundabout - 18 peaking roundabout - 10 that's a good level that always works there are situations where you would leave more Headroom but that's when you've got a really uncontrollable signal and you've got no idea how it's going to peak so in that case you might set your peak level roundabout - 20 just in case so that was easy we've covered half the ground already but what if you set your input gain too low what can go wrong then so I have three examples in the first I've set the peak to be around about minus 20 the second round about minus 30 and the third round about minus 40 so these examples will be rather quiet but we'll take a closer look in a moment I wandered lonely as a cloud that floats on high or day land Hill when all at once I saw a crowd a host of golden daffodils beside the lake beneath the trees fluttering and dancing in the breeze I wandered lonely as a cloud that floats on high or day land hill when all at once I saw a crowd a host of golden daffodils beside the lake beneath the trees fluttering and dancing in the breeze I wandered lonely as a cloud that floats on high or day land Hill when all at once I saw a crowd a host of golden daffodils beside the lake beneath the trees

what I'm going to do now is to compare all of these recordings by normalizing them I'm going to normalize them to quite a high level which I can do because it's already recorded and it's perfectly under control so here's my original recording which peaked -10 normalized to a good strong level I wandered lonely as a cloud that floats on high or Dale and Hill when all at once I saw a crowd a host of golden daffodils beside the lake beneath the trees fluttering and dancing in the breeze so we can compare that with the second recording that Pete closed on 0 dbfs which in theory should have a better signal-to-noise ratio but I don't think you'll hear very much difference I wandered lonely as a cloud that floats on high or Dale and Hill when all at once I saw a crowd a host of golden daffodils beside the lake beneath the trees fluttering and dancing in the breeze and the third recording which clipped we don't really need to hear that again but hey why not I wandered lonely as a cloud that floats on high or Dale and Hill when all at once I saw a crowd a host of golden daffodils beside the lake beneath the trees fluttering and dancing in the breeze now this is where it gets interesting because peaking at minus 20 DB FS a lot of people would say that's a bit on the low side especially people who have come up through analog recording where noise really was an issue you may be able to hear a slight increase in the noise level but in a real life recording it shouldn't be too much of a problem I wandered lonely as a cloud that floats on high or Dale and Hill when all at once I saw a crowd a host of golden daffodils beside the lake beneath the trees fluttering and dancing in the breeze and the recording that peaked -30 dbfs we're going to hear that that really is two lower level listen to the noise in this I wandered lonely as a cloud that floats on high or Dale and Hill when all at once I saw a crowd a host of golden daffodils beside the lake beneath the trees fluttering and dancing in the breeze and finally just to make sure you can hear the noise here's the recording that peaked at minus 40 DB FS once this is brought up to a decent level you really will clearly hear the noise I wandered lonely as a cloud that floats on high or day land Hill when all at once I saw crowd a host of golden daffodils beside the lake beneath the trees fluttering and dancing in the breeze so there you have it gain staging for the initial stage of recording three things don't clip leave yourself some Headroom and don't record too low in level otherwise you will have problems with noise I'm David Miller course director of audio master class thank you for listening

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