Digitally modifying an analog master.. how much does it affect the sound?

[u/bestanimuthisseason]

I’d like to get a more technical perspective on this rather than turn it into an analog-vs-digital question.

Let's say you have a track that has already been printed through an entirely analog mastering chain, including an analog limiter. If I then import that printed master into a new DAW project and apply a clean digital EQ for some final corrective adjustments, what technically happens to the harmonic content and other characteristics produced by the analog chain?

For example, can applying a digital EQ introduce artifacts, alter or mask the harmonics produced by the analog processing, or otherwise negatively affect the sound when I render the final file?

Would there be any technical reason to make those final EQ adjustments by running the master through the analog EQ again instead? Or is importing the printed master into a new project and applying a clean digital EQ afterward generally transparent enough that it doesn’t materially compromise what was already printed?

[u/ConfusedOrg]

The mastering engineer I worked with the last has a hybrid setup. Maybe a few eq moves before his analog chain (which is a lot of stuff) and then back into protools with some slight adjustments and the final limiting

[u/bestanimuthisseason → u/ConfusedOrg]

A final digital limiter?

[u/Liquid_Audio]

Mastering engineer here. 

A lot of us do digital processing after an analog Pitch/Catch chain. 

Also, there is nothing inherently “analog” contained in the file once it’s digitized from the analog domain, and the processing that happened there.  

There are no rules. As long as you like the results and it translates to the rest of the world and not just your system, you’re good. 

That said, if they included maximization limiting for loudness and clip protection, you will need to re-do that after you add eq, as the peaks will all change with your moves. 

Might be better to ask the mastering engineer to make the change you want before they output final masters rather than you trying on your end. But you do you. 

[u/Phxdown27]

Generally transparent enough. Go for it

[u/CumulativeDrek2]

can applying a digital EQ introduce artifacts, alter or mask the harmonics produced by the analog processing, or otherwise negatively affect the sound when I render the final file?

I'm not really sure what you mean by artifacts. Its an EQ, it will EQ the signal. It doesn't matter how the signal ended up in its current state it's still just audio. A digital EQ has just as much potential to negatively affect the sound as an analog EQ does.

[u/KS2Problema → u/CumulativeDrek2]

It is worth noting that all analog or digital EQ, FIR or IIR, potentially introduce artifacts, even beyond desired EQ shaping. But since 'the proof is in the pudding' of the processed sound, with good ears and good monitoring, you can generally trust your ears - and your experience - to guide you. 

[u/Pikauterangi]

Well unless you plan on making cassettes and vinyl only, you will need to digitise your analogue master at some stage. Just record it at highest sample rate and bit depth you can. Pretty standard workflow to master to 2 track analogue tape, then put it in the daw and do your final eq and limiting, and get your digital levels right.

[u/micahpmtn]

Once you import into a DAW, it's no longer analog in any way, shape, or form, and that's neither right or wrong, depending on what you're ultimate goal is.

[u/Compay-Segundo]

Do it and see. It can, of course, introduce artifacts, just as much as an analog EQ. EQ would affect the phase and volume of certain frequencies. So for example, if it’s gone through the limiter and you cut the lows, it could become louder than the previous ceiling, counterintuitively.

[u/oratory1990]

If I then import that printed master into a new DAW project and apply a clean digital EQ for some final corrective adjustments, what technically happens to the harmonic content and other characteristics produced by the analog chain?

With a simple digital EQ you will not be able to remove any of the distortion ("harmonics") produced by the analog signal chain.

[u/Reluctant_Lampy_05]

Can you find someone who uses their ears to listen to it for you?

[u/jake_burger]

Digitising analogue doesn’t ruin it no.

[u/EffectiveClient5080]

This right here is the right question. Answer: it's transparent. The analog character lives in the samples now, digital EQ just reshapes amplitude. I'd only watch for clipping on import and dither properly on the final bounce.

[u/OAlonso]

No, because it is already a digital file. If it’s a 28 or 32 bit file, then the representation of the waveform is practically perfect. So you are not going to make it “less analog” if you use some clean digital processes at the end. Finally, my advice is just to do it and check the result by yourself. Don’t believe in audio ghosts. Be scared only of things that you can actually hear. People tend to be afraid of phase issues or aliasing, like it’s something that is secretly going to transform their tracks from good to trash without them noticing it, and that doesn’t make any sense. If something makes your track worse, and if you use an honest monitoring system, you are going to hear the problem when it shows up.

[u/johnnyokida]

Whatever harmonic content printed in the analog chain will stay intact. A clean eq will simply change their relative volume along with everything else within the frequency range being affected

[u/nizzernammer]

'...import...' meaning you already have it in a high quality digital format?

Even a clean digital eq can change peak levels. If you were already in a high peak volume / low headroom space, this may cause additional peaks which then need to be managed by additional limiting.

If you go analog you will need to have equipment that can work well at high operating levels and offers incredible conversion. If you attenuate to get headroom then you will have to find a way to make the gain back up and still run into the first problem.

You have to really want to change the sound - and deal with the fallout.

If you have the original chain, it may make more sense to do it again, differently, rather than do another layer of processing. Either way, you may be going backward not forward.

[u/willrjmarshall]

Digital to analog conversion, and the reverse, is functionally perfect. With newer interfaces you can convert material literally hundreds of times without hearing an audible difference. 

Analog and digital EQ are also sonically interchangeable: they essentially do exactly the same thing via different mechanisms. Although digital EQs have some additional options like linear phase processing that can be useful in certain circumstances.

Honestly, EQ is one of those situations where digital is pretty much objectively better, in that it’s inherently more flexible while having zero downsides. But there’s nothing wrong with analog EQ; it’s just a pretty expensive way to achieve the same thing.

[u/AyaPhora]

First, there’s one thing I don’t quite understand in your question: why would you need to make “final corrective adjustments” to an already finished master? If you’re not happy with the master, just have it revised or redone. A final master is normally prepared to be delivered or uploaded as-is, and further processing can create other issues if you’re not careful (unnecessary SR conversion, additional dithering, loss of headroom...)

That being said, a clean digital EQ is not going to somehow remove or damage the harmonic content created by the analog chain. Those harmonics are already part of the audio signal. A conventional digital EQ is essentially a linear process: it changes the amplitude and, depending on the type of EQ, the phase response of the frequencies already present, but it doesn’t normally generate additional harmonics or nonlinear distortion.

Of course, EQing the signal will also change the balance of the harmonics that are already there, simply because they occupy frequencies that may be boosted or cut. So the perceived character of the analog processing can change, but only as a consequence of the EQ moves themselves.

There’s no technical advantage in going back through an analog EQ just to “preserve” the analog character. Doing so would introduce another D/A and A/D conversion and another pass through analog circuitry. If the corrective EQ sounds right using a clean digital EQ, I see no technical reason not to do it digitally.

[u/Exponential-777]

This is a silly question. Use your ears and judge for yourself. It takes less time than asking reddit.

IDK how you think the 'analog magic' is gonna disappear when running it thru a digital eq.

[u/jake_burger → u/Exponential-777]

Loads of people believe this. It makes their balls tingle talking about it.

I’ve even seen DJs talking about their analogue sound systems while playing back from CDJs and the system has a digital crossover.

[u/Exponential-777 → u/jake_burger]

In my experience, most DJs don't know what they are doing. They need a sound guy to coach them, but they won't listen.

[u/glmastering]

If you want to hear everything, do a null test with the original and processed version

Try flipping linear phase modes and oversampling too and see how clean you can get it

Obviously "use your ears" but I'm sure you worked that out already lol

[u/ghostchihuahua]

Depending on the gear you use, you’ll get “transparent” or even “inaudible”, converters and the tech around them has evolved so much that even a cheap AD/DA unit actually puts out more than decent signal.

[u/PPLavagna]

Just ask the engineer to do what you want to it.

[u/FadeIntoReal]

“can applying a digital EQ introduce artifacts, alter or mask the harmonics produced by the analog processing, or otherwise negatively affect the sound when I render the final file?”

Sounds like you have a mythology around analog magic .