Need Pros/Cons Of Recording - Mono Source to Stereo Track

Hi all,

Trying to learn something here so I figured I’d start a discussion on the pros and cons of recording “mono” audio sources to a “stereo” audio track. Please chime in to list some reasons for and against this practice. Again, just trying to learn a bit here.

Thanks a zillion… :wink:

My background…
I started using Cubase in late 2007 in my home studio. I primarily record myself and other talent mostly as solo tracks. I have recorded up to (3) tracks (audio and instrument) at the same time but that is very rare. During the last several years I’ve pumped out maybe 40 finished projects (songs) per year. Of the (40), maybe (15) per year are my original created songs posted to Sound Cloud. The others are “cover songs” not posted to the web but given to the friends/talent who record them with me for their personal listening use. None are for profit. A typical project has somewhere between 12 and 25 tracks (both audio and vst instrument). Also, I do not use any of the video related functions of Cubase.

Over these years I developed a habit to always record my “mono” audio sources (like guitar and mic inputs) to a Cubase “stereo” audio track. I adopted this method years ago when I first noticed that recording a mono source to a mono track will sometimes not allow a stereo VST effect to work (sound) properly. So I changed my workflow to always record my mono sources to a stereo audio track as this 'fixed" my stereo vst effect issue. My templates are all setup that way and I have provided advice to others on this forum to try this method of recording when I see an issue arise that I think may be related to it.

So that’s my story and the reason why I always record audio from mono sources to a stereo track. To be honest, I don’t know a reason why I would want to record to a mono track. Maybe the newer VST effects work properly when recorded to mono? Also, a mono source recorded to a stereo track is still recorded as a mono file. So why use a mono track? Am I missing an opportunity to create or do something special that can only be done from a mono track?

And this, my friends, is why I request the knowledge from the Steinberg user community.

Regards :sunglasses:

I’ve been doing the same thing, recording mono to stereo tracks for the same reason as you, I don’t think there’s any harm in it, I don’t think there’s any appreciable difference in file size between a mono and stereo track, I could be wrong. Storage is cheap, so that shouldn’t matter.

Congrats on the output, must be nice to get that much out in a year. :sunglasses:

OK there are many types of effects but when it comes to mono/stereo think of three types. Mono = 1 input and 1 output. Mono to stereo 1 input and 2 outputs and true stereo 2 inputs 2 outputs.

In the world of hardware, if you record a mono source one mic or input you would use the EQ on your mixer and insert your compressors and other dynamic effects. All this would be done on one mono channel of your mixer as it is only one audio. Most stereo dynamic effects are just two mono ones with a link function.
If you put that single audio onto a stereo track which is two mono tracks with the aim of keeping it mono you are now having to process two identical audio streams with two matching effects (remember stereo eqs and compressors are two identical effects one working on the L channel and the other on the R. If what comes out of the 1st output does not exactly match that coming out of the 2nd your 2 mono signals will not be lined and could sound poor.
OK to recap on this bit. For dynamic effect processing on a mono source it is more reliable to use mono dynamic effects …keep it as one signal in and one out.

Most delays, chorus effects work by having a single input that after treatment comes out of two outputs one sent to the l and one to the right …It is the time/pitch difference from the input that makes the effect and the difference from one output to the other that makes the effect stereo.

Quote “A typical stereo delay has a mono input and a stereo output, although a delay plug-in can (and most likely will) have a stereo input as well. On a stereo delay, as you know, you can adjust the left and right delay lines individually, thus creating a stereo effect. I’d feed a mono signal into a stereo delay. If you head for a stereo delay effect, it will most likely sound more stereo and more focused if you feed the delay with a mono signal than if you feed it with a stereo signal”.

If you want to add an effect to a collective of mono signals for example all the individual tracks of a drum kit you best option is to route to a stereo group, pan individual tracks from the mono source and use your stereo effect across the stereo field of the group.
For creating a space a true stereo reverb maybe best. The most practical way is to create a stereo fx channel and send you individual mono sources to this buss. Remember if you sing in a room you are singing in mono but what you hear with the acoustics added is stereo.

Of course rules are there to be broken.

Mono = one audio source
Stereo = two audio sources. I can see no advantage in turning one audio source into two identical audio sources.

Thanks… I can’t say that all of them are “Cubase worthy” but they sound OK to me. :wink:

Regards :sunglasses:

Hi Mrhehon…

Thanks for your explanation. I definitely get everything you mentioned before this quoted part (especially the “In the world of hardware” part. But, this part of your explanation is what is weird about recording mono to stereo in Cubase, and is why I don’t see the point to record to a mono track…

When you record a mono audio source to a Cubase stereo audio track you don’t get two identical audio recordings or two recordings of anything resembling stereo. As far as I can tell it is recorded as a mono file just like when recording to a mono track. File sizes are the same and they sound the same. A difference comes into play only when you decide to apply a “stereo type” of vst effect to that mono or stereo track.

Example… Years ago, when I recorded my guitar to a mono track, then added a vst effect to it (like a stereo flanger), the resultant playback would sound like one side of the stereo effect was being muted. If you copied that same recording to a stereo audio track then added the same vst effect to that track, it would sound as expected. This same phenomenon would happen on vocal tracks. Some stereo type reverbs would not sound correct when applied to a mono track but would sound perfect when that same recording and vst effect was placed onto a stereo track.

So to avoid the steps of moving recordings to the stereo track, I just started to record mono directly to a stereo track and never had an issue going forward. I can insert a compressor and whatever other dynamic effects without issue.

In Cubase, there might be real reasons users need record to a mono track. Maybe some special post mixing or mastering techniques require that it be done from a mono track? Maybe something else during mixdown or converting mono to real stereo? I don’t know of any. To be honest, I’m not even sure why Cubase has mono tracks available. If you or anyone else has some ideas please share them.

Regards :sunglasses:

Hi guys, after all that’s been said there must be no doubt about the differences between using stereo or mono tracks!

What I’d like to add is that nowadays it is possible to record mono audio in a stereo track, and I believe Steinberg enabled this to avoid bigger problems for the users who do this incorrectly (adding stereo tracks to record mono signals).

In the past, this would result in a stereo audio file with the signal in the left channel only, but now it records a mono audio file normally as expected (by the user who does this way). I believe this change was made to avoid big problems, or for using factory VST AMP Rack plugin which should be added to a stereo track eventhough the input signal is usually mono.

Still, in my opinion, you should choose carefully whether you want to use a mono or stereo track depending on the post-processing you will make (insert plugins). By using mono tracks and mono signals, you have less DSP load and avoid routing problems inside plugins as mentioned before.


Good point… Thanks :wink:

Regards :sunglasses:

As you can probably tell from my post, I never use a stereo track for a mono file. I need to experiment with this in cubase to see what is happening. If as you say (I am not doubting you) the file stays mono I can not see the point of the stereo track because as you know stereo has to be two files one to the L and one to the R…hence why mono on a stereo track should be two identical files.
I can maybe see the point of using the stereo track, mono file to go to a mono input stereo output effect like a delay, chorus, flanger for example though I would route to a group.
But what is happening with say an EQ or compressor…it is a single mono file going through a stereo dynamic effect. I gather it must be going to the 2 inputs equally and the same with the outputs, room for error and phasing.

Interesting conversation and I will look more into this “mono on a stereo track stays mono".

What most of you people are missing is: there is a difference between recording from a mono input bus, and recording from one side of a stereo bus. The first will record a mono file, the latter will record a stereo file with sound on one side only and that is not a recent change but has been in Cubase for a very long time already.

Stereo does not have to be anything: Stereo allows you to have 2 channels, there is no law, you need to have a stereophonic signal on your stereo busses, otherwise you would not be allowed to mix mono signals to a stereo bus, which is just the same: inputting a mono signal to a stero bus.

The same thing that happens to an insert on a stereo group that is fed by a mono signal.

Your point about recording from one side of a stereo bus (which will happen if you record a mono source thru an assigned stereo buss) is hopefully informative for those that did not know about this. So thank you :wink:

But I am also glad you brought it up because I missed specifying something in my original post. This topic was supposed to be about recording from a mono source (like a guitar) through a properly assigned mono VST Connection input buss to a Cubase stereo audio track versus recording to a Cubase mono audio track.

Unfortunately I missed adding the “through a properly assigned mono VST Connection input bus”. So I apologize if I confused anyone.

Try this short experiment for yourself to see and hear what I mean (I just did):

1 - Start a project with (1) Stereo audio track and (1) Mono audio track both set to 0dB in the mixer. Make a quick recording of a guitar to both of those tracks at the same time. Your guitar needs to be connected to your audio interface through a standard mono 1/4 jack connection and that input used must be assign as a mono input buss in the Cubase VST Connections menu.

Notice you will now have (2) tracks with a mono recording on each. If you check in explorer they show to be the same size files. When I play them back together and separately, for me, in the mixer they look and sound the same. Hopefully they do for you too.

2 - Next, assign the same VST guitar insert to each track. Choose a nice clear amp effect and add the same to both tracks. Amp settings must be the same.

3 - Next, add some kind of stereo guitar pedal (like a flanger) and add the same to both tracks. Adjust the flanger depth setting to max. Flanger settings must be the same.

Now, take a listen to each track together then separately. When played together I can plainly see in the mixer that the stereo effect on the mono track is playing back differently than the stereo track. When I listen to each track separately I can easily hear that the mono track is missing some of the stereo effect that I can hear in the stereo track.

This, my friends, is why I always record my mono sources (on a mono input bus) to a stereo audio track.

If you look on page 439 of the Cubase operation manual you will see this short note…

NOTE If you apply an effect to mono audio material, only the left side of the effect’s stereo output is applied.

The paragraph this is listed in is not “exactly” the same topic being discussed here. But… it makes me wonder.

Of course this same issue will happen for whatever audio you record on a mono track.

So why do it? Ever?

Regards :sunglasses:

With your flanger experiment you are talking about a mono in, stereo out effect. If you recorded through this type of effect hardware yes you would output the effect to 2 channels of your mixer and pan them hard L and hard R. or send them to a group.
You are still asking why use a mono track and the reason is the dynamic effects. When I mix a vocal before it gets to any stereo type effects reverb or delay it often goes through a filter, compressor, EQ and tape saturation all of which I want to keep in mono. When I want to go to the stereo type effects stereo groups and sends is the way to go.

Just for interesting reading here is a couple of links on this subject.

Anyway I have put too much time into this now and I wish you happy music making.
Regards Ian.

Just a final thought for you:
In Cubase you can do exactly the same thing that you describe starting with a mono file recorded on a stereo audio track.

Regards :sunglasses:

Kinda off topic… But, Weirdest 3D Vocal Effect: Ghost Reverb Mix Trick - YouTube
Has to do with mono to stereo bus…
(There are some nice tricks that you can do with plugins that let you unlink L/R) - alternative would be to use two mono channels and two mono reverbs?)
Anywho… Why did i even post this…?…

I haven’t fully understood what you’re doing since you haven’t said where you are putting effects.

In my own normal setup, I’ll record a mono source to a mono track. I’ll put mono effects in the insert chain (for example, an amp sim, a compressor, maybe a limiter). The output of the mono track after the last insert goes to the stereo master bus, or perhaps to a stereo group.

I’ll use a send slot for stereo effects, such as reverb, chorus, delays.

I guess I’ll have to try what you’re suggesting and see if I can duplicate the concern, but I have in the past played around with stereo inserts on a mono track, and I recall that as long as I sent the output to a stereo master bus, it worked fine. But since I don’t normally put a stereo effect in an insert slot, I could be wrong.

Well I guess you’re right; I just put a stereo delay on an insert on a mono track, and indeed only the left side is functioning. But as I said, I never put stereo effects in insert slots. So the point is, to put it into my words, if you always use a stereo input track for mono sources, then you can feel free to use a stereo insert effect.

I really don’t know if there’s a downside in terms of processing power; that’s the only drawback I can think of.

I do mix tracks very similar to the method you describe but I start with mono recorded to a stereo track. Why, because most of the time I’ll just add a few inserts to the track itself and be done with it.

But when the need arises to put mono effects in the chain prior to adding stereo effects to the output of that, then starting with the stereo track works the same as when starting with a mono track.

So recording to a stereo track from the get go lets you to do both methods the same (as far as I can tell). So that’s why I ask the question… Why is there a need to EVER record to a mono track?

So far in this thread this is the only possible pro I see for starting with a mono track. I guess I’ll check it out one of these days to see if there is a difference. My guess it’s negligible but, you never know until it is tried. :wink:

Regards :sunglasses:

I suppose the bottom line is that it is up to the user to do whatever works for themselves. There isn’t necessarily a wrong or right here.

But, I will say that it could make things very confusing for those new to recording. Way less complicated things can confuse a dood new to recording than this.

The simplicity of basic recording to mono tracks from a mono source just makes more sense to most and also to me as well. For you Prock, it makes sense for the way you work.

Other than ‘on the fly’ situations, I typically do not use inserts very often other than the usual mono eq/compression tools. I find it best for myself to create groups and FX tracks.

I don’t find that the way you are working is wrong, just not the way my head wraps around things.

Best to you and your projects. :slight_smile:

Hey @Prock,

i believe those two reasons are the main ones: less DSP load and having absolutely no problems in terms of cabling/routing, like @mrhehon said…

If you always use the stereo track, you will have to listen 4x more carefully and worry at least twice as much with every plugin you insert in that track…

When you are able to use a mono input in a stereo effect - e.g. amp simulators - the fx plugin either gives a manual option about how many inputs it will use (only left in, or “# inputs” for example), or it does that automatically, depending on the detection of input signal.

Many plugins that aren’t made with special care for mono input, like modulation, delays, anything pretty much except guitar fx, you have a big chance of having routing issues like one channel comes out clean, or out of phase, or whatever, when inserting plugins of a different configuration of its track, so like its been done since the 60’s, we usually go for the most perfect setup, like using mono tracks for mono inputs and stereo tracks for stereo inputs…

if you’re a modern one, you actually do record a mono guitar to a stereo track, in order to use an amp simulator in that track… but audio guys will mostly route the mono track to a group channel, and insert amp simulator there. It’s much smarter, bringing many more possibilities, than adding the amp plugin to a single track… (that would be the virtual version of soldering a physical guitar to its amp)

I believe that’s pretty much it… but depending on your style, if you know what you’re doing, you can break any rules man just make the track happen, that’s the most important part

Good summation. Thanks again.

Regards. :sunglasses:

My understanding is that Reaper has no distinction between mono and stereo…I guess if given a mono source it is doing exactly the same thing as being suggested here.
By forcing you to this behaviour I’d argue things are less confusing for newbies. They only need select mono/stereo in one place not both as input and channel as we are used to doing in Cubase.

As to mono effects on mono signals only…well I’m not convinced that a stereo compressor on a mono file/stereo track will produce any different effect than a mono compressor on mono track. Even if the plug has unlinkable channels it will apply the same effect because it has the same input. Maybe this is worth a null test for confirmation at some point.

So for me the last reservation for not using stereo tracks fed from mono is I think the CPU use. I may run a test project and see just what that difference is but it seems to make sense that 2 channel of effect will use more than 1.