Is Digital Amplification Bad?

[penguinpajamas]

Hey guys! So as I'm recording and mixing things, I generally try to keep as hot of a signal as possible, ideally using digital gain meters only to quieten sounds rather than amplify. Until now I've always been under the impression that analog amplification is alright, but digital amplification should be avoided, but recently I realized that I have no idea why this is.

If someone could share some insight as to why/if digital amplification (i.e. recording a quiet signal into Live and using utility to boost the levels) is bad, it'd be greatly appreciated.

Thanks!

[TomViolenz]

nm, I misread

[Angstrom]

Hey guys! So as I'm recording and mixing things, I generally try to keep as hot of a signal as possible, ideally using digital gain meters only to quieten sounds rather than amplify. Until now I've always been under the impression that analog amplification is alright, but digital amplification should be avoided, but recently I realized that I have no idea why this is.

If someone could share some insight as to why/if digital amplification (i.e. recording a quiet signal into Live and using utility to boost the levels) is bad, it'd be greatly appreciated.

Thanks!

It's not particularly bad as long as you are sensible about it. I'll give a realistic example:

Assuming you are recording an audio signal in through an audio interface then into a channel on Live the recommended peaking meter reading is ?18dBFS. You should usually refer to your audio cards mixer/software mixer if it has one, or failing that in Live's metering by expanding the track fader to show the DB markings.
The reason being that any tracking (recording a wave) is rarely compressed heavily and any sort of peak in the wave will be irrecoverably fucked into a square.
I have to confess I usually go above that recommendation though. I'm often peaking at -6. Because I'm a rebel.

Now the question: for amplifying that signal up later using something like Utility, or even the gain increase provided by a Compressor with Make-up gain, or an EQ, or any volume increasing device. Is that a problem? No.

Your wave was likely recorded by Live at 24bit, which gives a lot of headroom. Your noise floor (of your interface) will be around -120db. So you know you have at about 100db of headroom to play with (from -18 to -120). So if you are mixing and you use a Utility to raise your -18db recorded wave up to -6db your noisefloor is only getting up to -108. Still far below the hearing threshold.

I guess some people might misunderstand digital how the range of volumes are stored. The headroom. Perhaps people think that raising a digital signal somehow 'stretches' the bits out or something, and that a low signal raised will try to span the new dynamic range with the few sampled values. In fact that's not correct- it just moves all the numbers up a few places. like shifting a decimal point.

imagine this is a volume level of a single sample represented as a decimal floating point and the brown 7 is the noise
0.0000004312012012124157
and we want to turn it up, what that becomes is
0.0004312012012124157000

in 24 bit audio the real number would be much bigger, I'm only giving an easy to read example.
So , as long as you aren't recording peaks at ?90dBFS and introducing +80db of gain then you are fine.

[TomViolenz]

very well explained

[crumhorn]

Also worth noting that once inside Live the signal is converted to and processed as a 64 bit floating point number which has 53 bit precision. equivalent to a signal to noise ratio of approximately -318 dB. which is like the difference between the sound of a snow flake landing and something like an atom bomb exploding.

[penguinpajamas]

Thanks for all the info. So, just to clarify, besides from potentially raising the noise in the recording, there's no actual quality loss with digital amplification?

[yur2die4]

I think they are explaining How clean of a signal digital is, and how extreme of a circumstance you would need in order for digital to even begin to mess up your audio.

Analog on the other hand...... Part of the draw for analog is how it colors the sound. In many cases the result is pleasant. And that is why people like analog, it is not cold and sterile, it handles problems within its confines in a way where the laws of the universe smack back at the limitations. When adding gain, there are many ways to go about it, you can simply raise the level of a track where all elements are relative to each other, or you can do it in a manner where some types of material are treated in different ways than other. Analog in many cases has a knack for having a certain type of result, depending on the type of gear you use, you'll hade specific types of outcome. Digital will usually always produce the same result over and over again depending on the depth etc.

Then comes compression, filter/EQ, and noise/shaping/distortion. In the digital realm, you have to add these intentionally, and sometimes when you change the level of the clip, you might hear it in a way where you do want to apply these differently than when it was at a precious level. With analog, it naturally applies tiny amounts of these things even without intentionally adding them. So sometimes the result can be taken as sounding more brilliant, or in other cases it is more tamed, either way, if you have a tool you like, it handles audio in a pleasing way even before you begin to process.

Of course, I'm not an expert by any means and do not know this from actual trial and error. I'd love to be corrected if I've made any huge huge errors in my statement so that I can have a better understanding of audio processing

[crumhorn]

^^^^ Well put.

The only 'Bad' thing that comes from analog amplification is noise (everything else is a matter of taste).

When you are recording from an analog source there will always be some noise generated by the analog circuitry, so it's generally best to put your gain at the front end so that the signal is large compared to the noise. This could be seen as analog amplification being preferable to digital.

But the same principal applies all along the chain. So when you play your masterpiece through an amp and speakers you want to maximize the output from the DAW software, so in that case digital amplification would be preferable.

Most present day audio equipment is very low noise so in practice it's not much of a problem.

But the general principal is to apply gain to weak signals before passing them on to the next stage.

[jlgrimes]

Hey guys! So as I'm recording and mixing things, I generally try to keep as hot of a signal as possible, ideally using digital gain meters only to quieten sounds rather than amplify. Until now I've always been under the impression that analog amplification is alright, but digital amplification should be avoided, but recently I realized that I have no idea why this is.

If someone could share some insight as to why/if digital amplification (i.e. recording a quiet signal into Live and using utility to boost the levels) is bad, it'd be greatly appreciated.

Thanks!

Digital amplification is about the cleanest process in digital, just multiplication and division.

As long as you aren't clipping the master or mixing waaay below your meters, can't see how you will damage your audio.

In the modern days of 32 bit floating point and 64 bit double precision mixing engines. Digital amplification should be the least of your concern.

It is true that by recording low, you are not getting the maximum bits but you would really need to be recording low.

This is only bad if you are recording at an extremely low level like -48 db then you are getting back in 16 bit territory but once it is in Live, you are just basically turning up or down a 16 bit audio file so no loss.

24 bit vs 16 bit. Not much audible difference if any, the former just allows for a lot more headroom for recording.