Level difference in monitoring audio v.s. playback - Stereo Pan Law issue

I may be mistaken, but IIRC we ask for it since Nuendo v1. That’s 20+ years. Well, some solutions take a bit longer in software development…

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Thanks Fredo.

What I found: If one is using a Mono track, (indicated by the little “o” n the track itself, then all plug ins are mono, and indeed you cannot use the “mono to stereo” plug ins, as they remain in mono. If you take your mono audio file, and place it into a Stereo track, then you do get Stereo effects.

I’ll be posting this as an issue. AFAIK when you insert a “mono>Stereo” effect, it should then be able to be in Stereo, and pan things around or do Stereo effects. This is not the case currently. Using the latest Nuendo as of this post, 11. (whatever numbers … ).20

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I could not change the plug in IO configuration when in a Mono track.

Also, Mono > Stereo plug ins remain Mono.

Did a few experiments on a Mono track with a Mono electric guitar audio file. When I moved that same audio file to a Stereo track, I could then convert between Mono and Stereo IO configurations. It seems Mono tracks are MOno, Period. Stereo plug ins sound mono.

Test it…

I think the “mono to stereo” plugin or whatever it’s called takes a signal that is essentially mono but on a stereo track and creates a pseudo-stereo signal out of it. Maybe you saw that already.

Also, I don’t think this is an “issue” but a “feature request”. I’m guessing it might be a non-trivial thing to implement.

Nope, it outputs the same mono signal from both left and right. The panning becomes essentially a level difference between the two. But, Stereo processing simply is not used, it affects the signal as if it were dual mono.
A Mono>Stereo plug in will correctly apply Stereo effects to the incoming Mono signal, and output two different signals to left and right.

Try it. Do a Mono audio track with a Mono audio file, and put the Nuendo Chorus on it. See the meters? Mono, and hear the two channels? Both identical.


I don’t think you understood what I wrote.

I don’t think that’s up to you to decide. In modern music production, be it orchestral (something I spend a lot of time in) or more modern and mainstream genres is it very trivial to be able to apply stereo processes on mono sources. In fact, when I’m setting up a virtual orchestra I actually prefer ‘dry’ and mono sources to feed virtual space simulators for more control.

I’m affraid it’s you who didn’t understand. ‘Mono to Stereo’ is not a plugin, it’s a plugin mode where a plugin takes a mono source, applies it’s process to it (Reverb, delay, chorus, flanging, a virtual space, a virtual guitar amp, binaural processing) and outputs a stereo result. The usage I’m (we’re) talking about goes beyond just putting a bit of ‘Haas’ effect on a mono source. If this where the scope I agree it might be trivial but I in a modern DAW, to me, this sort of stuff is very important to get right, especially moving into VR territory, where you need absolute control over your sounds.

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Awesome! It’s been something I’ve been working around for years, as this has always been the case for every version of Nuendo and/or Cubase. Make sure to share the thread link, I’ll vote for it.


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If you want to “upmix” a mono signal to stereo then:

-Create a stereo buss
-Insert the mono to stereo upmixer in that stereo buss
-route your mono signal to that stereo buss.

=>>>Now your instrument has become stereo.

Unless I completely misunderstood what you are trying to so.

BTW. Upmixing is something we do in almost every surround project. (Stereo => Surround)


Fredo, we all ask for a simple feature that allows for changing the number of channels involved for processing any kind of input signal within the same track.


PS: Actually, we can do it already, but only by means of a few dedicated panning devices (… which makes this feature even more enticing).

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Thanks for chiming in again Fredo, and for offering this solution. I think you understood brilliantly.

While I am aware this is a possibility, on a typical project for me, this would add about 70 mix busses to my already crowded mixer, so I guess I am sticking to using mono audio files on stereo audio channels for at least my guitar parts for now.

However there is something else; I realize the discussion steered very much towards pan law, my initial problem was a different one namely:

To reiterate: When using a mono source on a stereo track, there is a difference in level between the monitored signal, and playback of a recorded signal. Pan law became a part of this discussion because I figured out this was of influence.

I'd rather have Dual Mono tho! Context:

When setting the pan law to 0dB, in stead of the standard Equal Power setting, the recorded signal becomes louder, cancelling out the 3dB difference between the recorded and monitored signals.

“So why not just set you pan law to 0dB?” I hear you think. Well, because I don’t want that. I actually like Pan Law to be on Equal Power. It helps keep your mixes in check, especially when considering mono compatibility/summing.

So I’d like to keep it for when I’m mixing and panning, but the way it seems to work now is when you use a mono signal on a stereo channel, Nuendo takes 2 identical versions of the mono source material, and pans one left and one right, applying pan law.

This would make sense when mixing, and when the left and right channels wherepart of a stereo recording, howver I’d like my resulting stereo channel to simply play ‘dual mono’ or rather: identical, non-panned versions of my mono source essentially one of which goes straight to the left, and one going straight to the right channel. This would make even more sense because you’d want it to sound equally loud in the mix, with or without panning applied as you would when the channel was a mono version.


I didn’t say “decide”, I was talking about programming Nuendo to do what you want. I said I’m guessing that that’s not trivial. If it was they probably would have implemented that already.

What I was talking about is a plugin, and I just checked and it is called “MonoToStereo”, it’s in the “Spatial” category.

Here, hopefully this clears it up a bit, from my perspective:

On my end, no. For many many many years, in the analogue domain, you would send a Mono signal to a Stereo device, and the return would be Stereo (2 channels).

When DAWs came around, they emulated this exact thing, as you are describing, meaning you send a signal to a “buss” or “aux” and it returns as a Stereo signal.

Now, imagine if you will, a Mono audio channel, in which you directly insert a Mono input < Stereo output plug in. Say a Stereo reverb. You are still in fact, sending a Mono signal into this plug in, and returning a Stereo effect back into that same channel No need to make elaborate bussing to do this, especially if your effect is only going to be used on one audio track, and / or different audio tracks will be using totally different effects.


Again, do this test on your own system:

Create a new Mono audio track and place in it a Mono audio file for playback.

Now, insert any Stereo effect you have into a pre (or post fader) slot. Now, for all of you who don’t remember, for example, Chorus can be either a Mono effect, but mostly it is understood to be a Stereo effect. many guitar chorus pedals in fact have Stereo outputs. Especially newer ones, like 20 years or newer.

So, now that you have your Stereo effect on this MOno audio track, what do you hear? On my end, it sounds like the EXACT SAME SIGNAL coming out of both left and right, aka there is NO difference in the processing. And, in my system I click on the plug in IO configuration, and it indicates it in MONO.

So, what happened to the Stereo or Mono<Stereo effect I just inserted? Well, it only works in MONO. The effect signal coming out of the plug in is “dual mono”, identical. Which is not what one wants with reverbs, choruses, flangers, panners, et al. right?

Other DAWs such as Pro Tools, Logic Pro, and Reaper, always configure the plug in IO to correctly input a Mono signal, and Output a STEREO signal. They all do this automatically and dynamically, when they see the type of plug in being inserted. As proof on any of those DAWs, you try to insert another Mono plug in AFTER the Stereo one, and it warns you that it either cannot do that, or it instantiates a STEREO version of that plug in.

This has absolutely nothing to do with “upmixing”, or bussing, or nada. Just the one Mono audio track, not being able to use any plug ins other than MONO. Making it more complicated to use, unecessarily so IMHO, since pretty much everyone else can and does dynamically change their plug in IO configurations according to the type of plug in inserted.

Reaper uses VST plug ins BTW.


PS for now, I am placing my MONO audio file, into a STEREO audio track, and then am able to use Stereo plug ins. Kind of counter intuitive… use a Stereo track to play back a mono source, but only if you need a Stereo effect applied to the Mono source.

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Hi MattiasNYC,

Just some points:

Reaper, Logic Pro, Pro Tools, all have had this “feature” for decades.

The VST implementation allows for dynamically setting the number of inputs and outputs of a plug in, when instantiated. This simply is not happening here in Nuendo.

On my plug in list, I see several plug ins which correctly identify as Mono, and ALSO have a version which says Mono<Stereo, along with Stereo. Meaning Nuendo does see their IO configurations, and lists them on the plug in list. HOWEVER, once you insert one of these mono<Stereo or Stereo plug ins into a Mono audio track, it becomes MONO. Nuendo makes them MONO, when I am expecting a Stereo return from the plug in. Like in almost every other DAW, and analogue consoles all over the World.

Mono in < Stereo return. Inside the same audio track. Like many other DAWs.

I may be doing something wrong, but nearly 23 years of messing with almost every DAW out there, tells me I am not. I am always welcome to be shown how to do this within Nuendo.


This pretty much sums up why I arrived at always using stereo tracks, even for mono sources. This works, however I noticed lately that using this ‘technique’, when monitoring an input source the signal will be louder then playing back audio from the track, which makes it problematic to use in some cases.

I understand what you’re talking about and I’m not saying you’re not correct and I don’t disagree with your feature request. As for the above though analog consoles don’t work that way. The path is either mono or stereo. It can’t change.

Ever worked on an SSL AWS 948 …? ;-D

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No. Does the physical wiring change?

In a DAW everything is virtual. In an analog console the paths are physical.