Direct Routing Doesn't use Pan-Law


Sends do. What’s the reasoning behind not having Direct Routing act the same?

It would seem to me that when setting up Direct Routing in order to generate stems etc the same pan law would be desirable. Not to mention that “The App That Shall Not Be Mentioned” has both its “Direct Routing” and its “Sends” conform to the chosen Pan Law.


I just checked this in Nuendo 5.5:

In Nuendo 6.0.6 changing Pan Law doesn’t seem to make a difference when measuring the signal at the output (i.e. Stereo source feeding mono-output with iZotope Insight in insert on output) when using direct routing. Using a send however does yield a different value in Insight.

In Nuendo 5.5 using direct routing changing Pan Law does change the meter reading on the output.

Is this a bug then?

18 views. Anybody?

In case you don’t see the issue here’s a real-world scenario:

  • Mix in PT. Deliverables (Scripps network) specify

    • Full Mix Stereo
    • A mono-mix of music+FX.
    • A mono stem of DIalog
  • In conjunction with that I print Mus and FX separately in stereo.

  • I also transfer the OMF to Nuendo (which imports incorrectly).

I brought this home in case someone wanted a small change which is exactly what happened: A substitution of dialog for Voice Over Narration instead. So I use the OMF source material to do the necessary and short edit, and simply punch into my stems and full mix. Now I realized that using the stereo stems, summing them via Direct Summing into my music+FX mono mix yields non-matching levels, despite setting the pan-law exactly as it is set in PT.

This is for a show that delivered yesterday and airs this or next week.

Surely somebody has input on this…


Who? :confused:

Please, can anyone confirm this?

I’ll have a look later on - but I freely admit I never use Direct Routing at all so would not have spotted this.

I’m not 100% sure I understand the question…
But when using direct routing the pan law should work according to the set prefs and the main (top slot) routing.
I can’t see how the pan law could technically change when swapping routing destinations, so it will always be defined by the top slot and then be folded down to any other format from the main/top slot channel width.

PT does not have direct routing and needs to use regular sends instead, sends in Cubendo and PT work the same way.

Direct routing can be a different beast at times and you really need to read up in the manual to understand how it works including how it deals with down folding and up mixing as it is different.

Let me rephrase it:

Should Direct Routing from a stereo track into a mono output be affected by Pan-Law?

Unless I am mistaking, it’s the other way around.
A mono track panned into a stereo track is subject to Pan Law.
A stereo track summed to a mono track is done according the downmix settings.
Unless I am mistaking, the chart of downmix values is within the manual.
What I know for sure is that they are identical to the downmix settings of the Euphonix consoles.


Here’s the manual section on Pan Law:

Stereo Pan Law

In the Project Setup dialog, in the “Stereo Pan Law” pop-up menu you can select one of several pan modes. These modes are required for power compensation. Without power compensation, the power of > the sum of the left and right > side is higher (louder) if a channel is panned center than if it is panned left or right.

To remedy this, the “Stereo Pan Law” setting > allows you to attenuate signals panned center > by -6, -4.5, or -3 dB. Selecting the 0 dB option turns off constant-power panning. Experiment with the modes to see which fits best. You can also select “Equal Power” on this pop-up menu, which means that the power of the signal remains the same regardless of the pan setting.

I think my understanding of it is correct. In addition I’m that If it only applied in one direction we’d see signal gain/loss going back and forth (meaning that if we went stereo to mono to stereo (or vice versa) the level would have changed even if we selected a pan-law of equal power, since it only applied in one direction), if you know what I mean.

As I mentioned earlier, I understood “downmix” to apply to signals greater than stereo only. I read that section on downmixing and if you check the values they specifically refer only to surround formats.

I just tested this.

A -9 dB stereo 1kHz signal routed into a mono group gives following results:

-Pan Law @ 0dB: Group level = -9dB.
This means that a downmix 6 dB attenuation is applied.
-Pan Law @ -3dBdB: Group level = -12dB.
This means that a downmix 6 dB attenuation and a 3dB Pan Law attenuation is applied

So that seems correct to me.


Can you be more specific please:

  1. Which Direct Routing slot did you use (does it happen in all slots?)
  2. This was a stereo source, right?
  3. Also; does it still work when sending FROM a group to an OUTput?

Btw; it looks odd that 0dB pan law results in the same measured level after summing. Shouldn’t it be the opposite? Shouldn’t a “-” reduce the level? Or are you routing stereo to mono to stereo output and measuring the output?

All slots of direct routing.


There no Pan Law is applied, only the downmix attenuation, which again is normal to me.

That seems correct to me. Pan law attenuates a mono signal panned in the center by the amount of of the Pan Law settings. When set to -6dB, the combined signal from Left + Right (panned in the center) is reduced by 6dB.
Setting the Pan law to 0dB results in no Pan Law applied.
Only the 6 dB downmix attenuation is applied (two collorated signals summed results in a 6dB level increase)

No, I am measuring on the group channels. Just look at the metering.

I don’t understand why you want me to do these tests, do you get different results on your system?


It doesn’t to me though. In the manual Direct Routing is said to do automatic downmixing according to the table you referred to, but that applies to 5.1 and higher only. I think it’d be more “normal” to have pan law apply to the entire signal chain instead of excepting one destination. But see my last reply however…

You’re right I think. I guess I thought of the way that looked in relationship to what I am trying to achieve, which has to do with summing stereo into mono rather than spreading mono into stereo, if you know what I mean.

Yes and no. And that’s what’s currently worrying me.

Earlier I got different results than today. I had a stereo source that found its way onto a mono track through groups/outputs and there was no pan-law setting at all that could make the levels match. That was very worrisome to me because it’s been my impression and experience (with other DAWs) that a change in pan law should make levels match.

Today however I opened a brand new project (again) in which I did what you did: I set up a stereo track with a generator at -9dB feeding a mono group. Just like you I’m getting different results according to pan-law using Direct Outs in different slots.

I did not get this before.

In addition to that I’m seeing the same result on outputs!

I’m just not sure what to think about all of this. I wanted anyone to try it and hopefully prove me wrong so that I know what I want to accomplish is possible in Nuendo. It seems that it is possible, which is good, but I’m now left with the feeling that I need to run tone through my signal path everytime I boot up just to ensure there’s nothing whacky going on. Either that or something is seriously wrong with my routing, which I honestly doubt. I could be wrong however.

Anyway, thanks for checking. If you have any more input on this I’d be happy to hear it.

More tests.
It indeed seems that Pan Law is not applied when routing to a mono output.
I can only guess that this is because in a config with multiple outs, normally the smaller channel configs are generated through the Send slots of the main (widest) output channel.

Another anomaly you could have seen is when using regular audio material.
Two collorated signals summed results in a 6dB level increase, but summing two uncorrolated signals result in only a 3dB increase.


But it did when I just tested it earlier!

Ok, I’ll test this.

Actually the problem that made me test this in the first place was that I both heard and saw a difference at all, and couldn’t get rid of it through Pan-Law settings.

Either way I think it would be good for Steinberg to tell us how this should work, don’t you? That way we know what we’re supposed to look for in a sense.

What Pan law setting do you have in your Soundcard?
According to Steinberg, it should be set to -3dB.


I’m not sure I see how that would change anything. I have a Lynx TWO-B and it has no settings for pan-law as far as I know. All my routing is “1-to-1”, meaning Nuendo output 1 goes to Lynx output 1 (lynx mixer) which goes to physical 1. Never any cross-routing or “splitting” or “summing” of signals on the card.

If you are using ADM, then it will have an impact on your incoming mic signal.
Just thinking out loud…