Basic questions about recording and mixing with Model 12

[Bambi]

Wow, how many things to talk about. First of all, Arjan, thank you very much for your clarification. For me it's really relieving not having to worry about distorting as long as the recorded signals and the ones going out of the mixer are within the safe threshold. It's a wonderful advantage of the digital equipment.

Mark, have you done this test specifically to check what we are discussing here? Because it is very interesting from an empirical point of view. It's great to have Arjan's advice and your own results as a reinforcement. I get many things out of this conversation, the most importants perhaps being the great advantage of forgetting about some of the distortion issues more proper of the analog domain, and the several unity gain best practices throughout the mixing process

 

[-mjk-]

@-mjk- I said, and I chose my words carefully, "everything you do digitally inside the mixer cannot distort your signal, until you go back to analog."

A digital mixer adds signals together (like any mixer) and therefor must accomodate - internally in the digital domain - for signals higher than 0 dB. Two or more individual channels of white noise, both at unity gain, will produce a signal higher than 0 dB, but this is an internal calculation result for a digital mixer, NOT distortion. The master fader, just before going back to analog is there to make sure the resulting signal stays below 0 dBFS - hence, no distortion.

@Arjan, is clipping, distortion?

 

[Arjan P]

Feels like a trick question.. what's your premise, @-mjk- ?

 

[-mjk-]

It's not a trick question @Arjan. I'm asking if you agree that clipping is distortion. My digital console can make the signal so hot that it clips. The red clip lights on each channel and the main bus indicate clipping. So at least in the X32 it would seem that it is capable of clipping.

 

[Arjan P]

Well, looking through the specs, I see the X32 uses 40-bit floating point internal signal processing so any clipping you see must have to do with AD or DA stages of the mixer. Also possible is that in the design philosophy of the mixer they want to warn the user for high signal levels at intermediate (digital domain) points, but I wouldn't know about that ofcourse. Interesting here is: do you see a signal indicated as 'over' or do you really hear distortion?

And yes, I can also make clipped signals inside the DM-3200, but only by going too hot into any AD stage, going too hot out of any DA stage - or going too hot digitally through the digital buses that connect to my mixer (either FireWire from Cubase, which is limited to 24 bit fixed or ADAT with another interface I sometimes use - also using a fixed bit signal) .

 

[Bambi]

I think what Arjan means is that, although you see the clip indicators lighting, they are just a visual reference to know that, if you send that signal through the D/A converter, you are going to clip at any stage that comes after that conversion, be it a monitor or any other device. But as long as the signal stays inside of the digital mixer, it won't distort sonically, only visually. And the best way to check it is to listen to your visually clipping mix through your headphones connected to your mixer, and then contrast it with the sound on your monitors. According with what Arjan says, the headphones would deliver a clean signal while the monitors would distort, as they would receive the just converted analog signal. That's what I interpret, but I'm not sure if it is that way

 

[-mjk-]

All this theory is great. But until there is a digital pathway into the human auditory system, I have to worry about levels because in the end, I'm listening through some kind of analog speaker.

Yes, sometimes I do hear distortion. It's pretty conservative, seems like.

 

[-mjk-]

....if your analog gain on a channel input is such that the digital signal is at 0 dB (so just no distortion) then everything you do digitally inside the mixer cannot distort your signal, until you go back to analog

I can't help it, lol. This is like having money in the bank "tax free" until you withdraw it. Then you get taxed. In the end you need to treat your money as if it's being taxed.

 

[Arjan P]

You know what they say: two things in life are guaranteed. 1. Paying tax 2. Death.

 

[Mark Richards]

Bottom line for me: Red is bad.

Bambi, you'd asked for some free online resources.

Here's a few from Harrison Consoles' Mixbus tutorials:

"Gain Staging"
"Clipping v Clipping"
"Metering"​

While specific to using Mixbus, they also have a lot of general information. Just ignore the marketing pitch.

 

[Bambi]

Hello everybody. I agree that red is definitely bad whenever it shows Anyway, I find all your comments very helpful

 

[Bambi]

And Mark, thank you very much for the links. I'm going to take a look

 

[Bambi]

I'm thinking that maybe I said a foolish thing regarding the MJK question about clipping and distorsion. Rethinking it, I misunderstood the way the signal goes out through the headphones, as there must be a digital to analog conversion in that process too, right? In that case they would work exactly as the monitors. However, the Arjan explanation about the signal not clipping inside the digital mixer, together with the Mark tests, are very revealing. Although MJK's example of paying taxes anyway later it's also very self explanatory

 

[-mjk-]

@Bambi You haven't said a single foolish thing at all! In many cases, theory, while being interesting, isn't always useful. There is the classroom and then there is the field.

 

[Bambi]

Thank you MJK. I agree with your vision about theory and practice

 

[Elvis Plissken]

I have a basic question.

Just bought the M12 last weekend and have been reading/ watching as much I can absorb in a that small amount of time.

Right now, I just do DAWless synth recording at home and my previous workflow was with analog mixers > H1n Zoom recorder.

So my first challenge is the wrap my head around the digital differences/routing and what options the M12 offers that I need and don’t need so I can keep my eye on the ball. Right now I just want to do basic mixing and record to the SD card. I plan on getting dedicated PC/DAW for recording in the near future but for now…

I did my first ‘MTK > stereo mixdown > SD’ test recording last night and I don’t think I routed the external FX (Aux 1 > stereo delay/verb pedal > stereo channel 9/10 ) to ‘post fader’ (assuming I can do so?)

Another thing that I didn’t do or consider is to record channel 9/10 (wet FX signals). Do I need to do that as well?

 

[Max Relic]

@Elvis Plissken you can set Aux1 pre/post preference in the menu MIXER, when set to post fader you will see a LED permanently lit as a remainder (default is Pre). It's your choice to print FX return on a separate track, generally it depends on the project you are working on. You could record it on 9/10 in the first take as a reference for getting the right feeling, then decide to keep it or not when doing overdubs. Search my post in this section on how to overcome the 12 tracks limit and live happily DAWless.