How do you make sure you are hitting Nebula at -18dbfs?

[mchillak]

Sorry for the dumb question. I'm very new to Nebula and i'm still trying to wrap my head around the work flow. Would I put some sort of gain plugin with a meter pre-nebula or is there an easier way?

[Mercado_Negro]

This is how I work (hopefully others will join us and share their methods):

1 - Download the -18dBFS tone from the attachment below.

2 - Calibrate your host meters with this signal.

3 - Insert a Nebula instance and check if "4 RMS 17" is set as metering scale.

4 - Check Nebula's meters:



5 - Done, keep your tracks at this value (or below).



After some tests I've come to the conclusion that a safe value for tracks is -12dB or -11dB (that's why I suggested to calibrate your host meters in the first place), look here, this is an example with Reaper and calibrated meters:



To keep my tracks within this range I use 2 plug-ins, before and after each nebula instance (in my case, using Reaper, I use the JS effect "volume_pan"). I use 1 plug-in to control the signal that's going into Nebula and another one to compensate if needed (this is what we call "gain staging"):


(click on this picture to enlarge and see all meters and descriptions)

Nebula

-18dBFS_Signal.wav

(2.75 MiB) Downloaded 580 times

[mchillak]

Fantastic! That makes sense.

Thanks.

[akb44]

Should Nebula always be run at -18dbFS rms?

[enriquesilveti]

-18dBFS as average level of audio signal is an European standard and means 0 VU. Nebula works like a analog hardware so use standards of the analog world > -18dBFS = 0 VU. If you work with 32/64 bits float system is almost impossible to distort but at the very end you must do a DA to listen into yours speakers in 24 bits fixed, so an average level of -18dBFS is a safe value.

[tumburu]

"an average level of -18dB"

[enriquesilveti]

"an average level of -18dB"

Edited

[tumburu]

Oh, sorry, this was not addressed to you. I was just emphasizing that we're talking about the average level, not the peak level.

[milosh]

do you guys know if it is possible to calibrate meters in Ableton Live ?

cheers

milosh

[scooter]

Wouldn't it be as simple as Normalizing the WAV file to -18dbfs "average" and not peak? Making sure to keep them at 32bit or 64bit float

[ngarjuna]

Wouldn't it be as simple as Normalizing the WAV file to -18dbfs "average" and not peak? Making sure to keep them at 32bit or 64bit float

If your host does that, then yes, it's a possible working method. However...I don't really grok the concept of normalizing to an average conceptually (I have no idea how other hosts handle it, mine doesn't do any RMS/average normalizing). The whole concept of normalizing involves taking the highest peak and setting it to the normalization value, adjusting everything else by the same amount. When you're talking about average, you're talking about the highest average value and matching that to -18? What kind of RMS window are you using (because that's going to vastly change your RMS reading)? Seems like an awful lot of "engineering" being automated in a way that's kind of out of control and arbitrary.

Gain staging used to be one of the main things that audio engineers worried about in a session. It's part of how you get nice sounding mixes (I realize this is a debated matter; suffice it to say I'm firmly in the "gain staging matters a lot even in digital audio" camp). It shouldn't be looked upon as an extra step (although, all too often, it is). Having 1000+dB of dynamic range doesn't render gain staging useless; there's a lot more to it than just making sure you don't clip. But even if you're in the "gain staging isn't necessary in digital" camp, using Nebula to replicate analog devices does require some attention to this detail.

Just my curmudgeony opinion. I also had to walk to school uphill both ways =).

[fmacor]

If i'm hitting Nebula at -18dbfs, could i use the Nebula input gain to saturate like analog or do i only need to use the DRIVE?

[enriquesilveti]

If i'm hitting Nebula at -18dbfs, could i use the Nebula input gain to saturate like analog or do i only need to use the DRIVE?

The right way is using input gain, you can use drive also, but you will change the relationship between fundamental and harmonics, some times is good for create an exaggerated harmonics.

[fmacor]

In wich way do the DRIVE will change the harmonics relationships?

[mordecainyc]

In another topic, Alex B said the following about this:

To set the gainstaging in the mix with nebula.
If you take -18dBfs as 0dBVU as reference, this -18dBfs are RMS value, not peak value. Also, I don't suggest to use - if it is not strictly necessary - a plugin to lower the audio level, use the Nebula input control.
Exsample: you have a kick drum track which sound at -6dBfs peaks. Put Nebula as first insert FX, load your preset and leave it flat (unity gain) than play the track. Lower the Nebula input control by -6dB, now you should read -12dBfs peaks on your DAW meter. That's all. Don't rise up the output level, it's not necessary. Now you can insert more Nebula or other plugin instance with the correct gain staging. Do the same at all your tracks.

see http://www.acustica-audio.com/forum/ind ... t=50#p3733


FYI, this was a reply to my suggestion to put a gain trimming plugin (-18dbs) before Nebula plugins, and then another gain trimmer after to turn up the gain again.


Alex' reply sort of implies that (i) we should not use external gain trimmers (or DRIVE slide), but instead the input knob to reduce gain, and that (ii) the input knob should not be used to drive up the sound to go over the -18dbs (RMS) preferable gain stage, or at least not very much.


I guess we should use the input knob (instead of gain trimming plugs or DRIVE slide), but we should just be careful not to drive it up too much (i.e. just a few more db's than the preferable gain stage)? Am I right or does anyone have any other thoughts about this?