One of the most common questions that comes up is: how do I set levels? And understandably so. Level setting is crucially important to getting a good recording, and yet there is no clear, simple guidance out there on how to do it — not because people don't want to help, but because there simply isn't any easy set of rules for this.

In my video episode "Technique", I give a basic introduction to level setting, which essentially says start at -12dB and err on the low side. I think that's reasonable advice as a starting point, but it's still pretty minimal; again because, at least as far as I know, there just isn't any simple set of rules I can tell you about.

Despite this, I'm going to have a go at providing more explanation, which might help a beginner to get through this. Please remember that I'm no expert field recordist, and I'm really just figuring this stuff out myself; but maybe this will help.

Know Your Meters

Your meters are the key tool that you will use for setting levels. Trying to figure it out by the loudness of the sound in your headphones is hopeless, because that will totally vary depending on your recorder's headphone amplifier, the sensitivity of your headphones, and of course the setting of your headphone volume. And the sensitivity of your ears! The meters on your recorder are the only real guide you have.

So the first thing to do is understand your meters. And yes, this will mean reading the manual — sorry!

The Roland R-26 and its level meters (click to enlarge). The scales are marked with numbers, although the '-' signs are not shown.

Your recorder's meters should be calibrated in dB, or decibels. (If not, perhaps you should look into getting a real audio recorder.) If it has actual numbers along the scale, as with the R-26 shown here, so much the better; but it should at least tell you the levels in dB, and have marks on the scale corresponding to key levels, like -12dB in particular.

The Tascam DR-701D and its level meters (click to enlarge). The dotted lines mark -20dB and -12dB, and the peak levels are shown numerically on the right.

The loudest end of the scale — the right-hand end — is generally 0dB, and quieter levels are negative numbers. This might seem backwards, and if you want to know why, read about logarithms; it's too much to cover here. But basically there's no such thing as a quietest sound. The loudest sound is clear-cut — it's where the digital samples would be larger than the largest number you can record, and so the audio would clip. So that's our reference point; and the crucial thing about setting levels is to never let the meters go above 0dB.

(If you have floating-point recording, then you have a lot more flexibility than this; but that's a whole other subject.)

So know your device's meters; know how to read the display, and what the various markings on the display mean. In particular, know where -12dB is on your meters, because that's a handy reference point.

Basic Level Setting

The basic advice about setting levels is fairly simple:

If your source is really constant, you could turn the levels up above -12dB; but there's not much point in this, because the dynamic range of modern recorders is easily enough to capture everything, clearly, at -12 or even well below. Remember that the level you record at isn't the level of your finished, published work; you will set that level when you edit.

That's just a basic rule of thumb, but at least this might get you started for recording in a simple setting, where you can monitor the subject as you set up. But life isn't always that simple, so read on...

Advanced Level Setting

The true story is that nobody can tell you what to set your levels to, because there's no one right answer. This is a skill which you need to develop in yourself by practising with your gear, until you understand the effects of the level settings.

Let's say, for example, that you're setting up a mic to record a quiet cityscape at night. What level should you set?

If you follow the advice above, and set the ambient sound when you're setting up to be at -12dB, then your recording will likely be way too loud. While you're setting up, everything is really quiet; but maybe later on some foxes start quarreling right in front of your mics, and your recording will be hopelessly clipped. Or the dawn chorus starts at 4am and is surprisingly loud.

The issue here is that you can't set your system up for the loudness of your subject, because the subject isn't making sound — or isn't even there — when you're setting up. So what do to?

Clearly a good guide here would be to start at a much lower level; maybe set the meters so that the basic ambience is just making the meters move definitively above the bottom of the range, maybe around -40dB. Then you'll have plenty of headroom if something interesting comes along later. But will that headroom be enough? Or too much?

Only experience can tell you that. Try it, and see what happens. Then try something different. And this. unfortunately, is the answer; you just need to experiment, get familiar with how the system works, get familiar with your subject, and then develop an instinct for how to set the levels. Of course it's not easy, not least because your subject is always changing; but that's it.

Really Quiet

If you're recording really quiet sources, it might be worth doing some controlled tests with your gear. Some recordists report that a recorder gets a lot noisier at the top of its gain range, so it might be better to record lower and boost in post; however, some recordists report the opposite! Personally, I've usually been surprised at how much a quiet recording can be boosted later and still sound good; but whether this works for you will depend on your recorder.

So test your gear — record a very quiet source at medium gain, and at high gain; then boost both recordings in post to the same level, and see which one has less noise, in terms of hiss from the recorder.

Controlled tests like this can really help you to get the best from your gear, so if you're stuck indoors on a rainy day — or in lockdown — give it a go. At the very least you might learn something about the characteristics of your equipment.

Addendum: Floating-Point

If you're lucky enough to own a recorder with floating-point recording, what then?

Well, I've only recently started dabbling in this myself — and in fact the concept is new enough that there isn't a lot of knowledge out there — but my take on this is, do it just the same as you would with conventional (integer) recording. You just don't need to be so worried about going over 0dB and clipping, because you can pull the recording down in post. But the level knobs will set the "default" level of your recording, and keeping that in a sensible range seems like a good idea to start with.