Last Updated on February 27, 2020 by Facundo
Well, there’s a good answer to this question… one that I will try and explain as thoroughly as possible in this post.
The simplest explanation I can give is this;
Checking a mix in mono and not only in stereo is to make sure that it still works and sounds right for mono listeners.
A mix that sounds great in mono will always sound great in stereo, but not the other way around. Mixing in mono will reveal if your mix is complete or not.
This is because a lot of small radios are mono, many car radios also automatically turn to mono if the signal becomes weak.
Also, sometimes internet files are played back in mono, since this way they will take up less bandwidth.
This is why it is very important to check that a mix works well both in mono and stereo.
So, mixing the entire song in mono is a mistake, you should mix the way you intend to listen to the song, which is stereo.
But you still need to check how the mix sounds in mono as often as possible.
Table of Contents
- It forces you to mix properly
- Great at exposing phase issues
- Fixing phase issues
- High-pass the low-end
- What should be panned?
- How to playback in Mono?
- Panning in mono
- Should you use Stereo Width Plugins?
- Compare the mix on cheap monitors
- Can you mix in mono using headphones
It forces you to mix properly:
At its core, mixing is just about adjusting the relative volume of the tracks, the frequency content and the stereo position properly.
If you remove the stereo position, it will let you focus more on the other two and it will make it obvious where things need some tweaking.
If you have two tracks, one totally panned to the right and the other to the left, it will be easy to discern what’s going on in each one because of the stereo position.
But as soon as you switch it to mono and they are both coming out through the middle, if the volume wasn’t set properly or if some more EQ or compression is needed, it will be much harder to identify what is being played in each track.
I’ll give you an example;
If you record a piano, guitar and vocals, while in stereo you will definitely be able to hear everything clearly, but when switching to mono you may feel the guitar getting lost behind the piano or vice versa, and this issue happens quite often.
So, switching to mono from time to time will allow you to create better all-around mixes and generally avoiding mistakes.
Related: How to remove noise from an Audio Recording.
It’s great at exposing phase issues.
When panning instruments, since one is coming out the right monitor one the other one is coming out the left monitor, it’s impossible to get phase cancellation problems.
But as soon as you collapse everything to mono, if those tracks are slightly out of phase with each other, you will run into some issues.
This is especially true in the low-end.
Why is this?…
The lower frequencies have bigger wave forms, so it becomes a lot easier for them to be out of phase with each other.
Imagine you are recording a rock song and you have 2 guitar tracks on each side, or even 4… If those get slightly out of phase, which most likely will happen, as soon as you collapse them to mono, they will start to cancel each other out, thinning the tone and effectively sounding smaller.
Not only will this thin out the tone, but it will also sound muddy and won’t let the bass come through.
This is why switching to mono can be so effective, because you will be able to check whether or not you are running into phase issues.
How do you fix the Phase/Polarity Issues?
You could try clicking on the polarity flip, which will simply invert the waveform of the track you selected.
This MIGHT help but only to a certain degree, because if two tracks are out of phase just slightly, using the polarity flip won’t really get them back in phase but rather change which specific waves are out of phase.
This would only really work if the tracks are 100% out of phase, or at least really close to it.
The best way is to zoom in and check the wave forms directly.
You will be able to see that on e.g. Guitar 1 the peaks may not align directly with peaks on the Guitar 2 track. Here you can take one of these tracks and move/nudge them a bit in the right direction until the phases align.
I find this to be the best way to go about it, it requires a bit more work but the result is great.
Phase issues can happen on all frequency ranges, but mostly on the low end.
Which brings me to my next point…
High-passing the low-end.
Using high-pass filters on the low end may do your mix a lot of good.
Let’s take the previous example of the two or four guitars, which are panned to the sides.
While panned, everything will sound great, because they are not competing with other frequencies that are coming out through the middle, like the Bass, Kick- or Snare-drums, etc. plus, there are fewer phasing issues, the only ones you can get are between the guitars on the same side.
As soon as you collapse into mono, those lower guitar frequencies will overlap with all the other ones, like bass, kick-drums, etc. and the mix will get muddy, while panned you can clearly hear every instrument but as soon as you go into mono it becomes a mess.
So, imagine having about eight guitar tracks together, the low end WILL get super muddy and also all those big wave forms will probably be a bit out of phase with each other, thinning out the tone.
What you can do here is use a high-pass filter on those guitars only to remove some of that bottom end.
What will this do for the mix?…
First of all, like I discussed above, the lower frequencies are more prone to phase issues so, removing some of those frequencies can alleviate this problem and you eliminate the muddiness.
The second benefit is that the bass will now cut through the mix properly, which will end up giving you an increased lower-end perception.
Another thing to take into account is that the lower frequencies usually feel a lot more omni-directional, this means that even if you pan them you won’t get as much stereo separation as with higher frequencies.
So, if you plan on panning certain instruments, like Guitars, removing some of the lower frequencies from about 150Hz downwards, can help a lot with the stereo image.
This is especially true in rock music, because the bass tends to play exactly the same part as the guitar, so it all ends up blurring together.
This may sound counter-intuitive, because I’m saying that removing some of the lower frequencies can actually increase the perception of the low-end, but it works great.
What should be panned?
Of course, there are some elements of the mix that can and should be panned, but there are some others (always depending on the genre of the music you’re mixing) that should be dead center.
What usually goes in the center?
Lead Vocals, Bass, Kick- and Snare-Drums.
Everything else can be panned.
Depending on the part of the song, you can pan stuff only half-way to the left or to the right and then in the choruses create an automation to hard-pan to create a wider feeling.
This all comes down to what you feel the song needs.
How to playback in mono.
If you have an Audio Interface with a mono switch, you can use that to collapse your mix into mono. But if your Audio Interface doesn’t give you that option, here’s a way to achieve this through your DAW.
With ProTools you can use the “Air Stereo Width” plugin on the master output and decrease the width to zero. Now you’re listening back in mono.
In Reaper you can simply click on the Mono button on the master Channel.
If you’re using Cubase and you don’t have a stereo enhancer plugin, download A1StereoControl and put it in the master output. Then decrease the stereo width to zero.
You can download it for FREE from this link.
Real Mono and Pseudo Mono.
You might switch to mono, using these plugins or switches, but you will still be hearing through two Speakers, true mono would be only listening to one speaker.
Try turning one off completely and check the mix on just the one Monitor.
Does panning in mono actually work?
I read a lot of posts online where they claim that panning instruments left and right will actually give you a stereo feel while in mono.
When panning in mono you are only lowering the signal of that particular audio, since you’re moving it further away from the center. But this doesn’t give you an increased stereo perception when listening in mono, it only decreases the level of that track.
It works as a really sensitive fader, but if you adjust it this way while in mono and not stereo and then switch back into stereo, the actual panning will kick in which isn’t really what you wanted.
This is why, you should only really pan in stereo, then switch to mono to check how everything sounds, then back to stereo, and so on.
Should you use Stereo Width Plugins?
While getting a huge stereo image might sound great in theory, I find that it’s not worth your time mainly because most people won’t even be able to listen to it.
If you’re in a mall, restaurant, etc. IF they are playing music in Stereo, you won’t be able to hear it because of the distance, plus they usually play it in mono.
Also, in most homes you might find that one speaker is in the living room while the other is really far away, maybe even in another room.
There are some plugins you can use to increase the stereo width, but these use phase shifts to do this, which as soon as you collapse back into mono will create more problems than solutions.
So, no. I don’t recommend them unless you have a specific purpose and know exactly what you are doing.
Compare the mix on cheap monitors.
You should try and listen back to the mix on cheap monitors and headphones, or even cell-phones, small Bluetooth speakers, etc.
The great thing about this is that you will be listening to how your mix sounds in the exact the same way most people will, no one is sitting at home listening to music on expensive Studio Monitors.
This is really useful to help your mix translate into the real world.
Can you do this using headphones?
While you will probably do the bulk of your mixes with Studio Monitors, mixing on Headphones can be done as well.
But, can you actually switch to mono while using Headphones?
Absolutely, there’s no reason not to. The only thing, I find, is that I feel every sound right inside my head which I don’t personally like that much. I find it better to use them in stereo.
But go ahead and try it!
I wrote this article on how to get great sounding mixes using only Headphones, which you may also find useful.
Mixing in mono will definitely help your mixes translate into the real world a lot better, but remember that you will ultimately want to mix the way you want your song to be heard, which would be in stereo.
Also, since you need to be able to process the track a lot better, by this I mean applying EQ, Compression, etc. not only will your mix sound great in mono but as soon as you switch back to stereo it will sound even better.
Don’t mix the entirety of the song in mono, but switch between mono and stereo to be able to compare how everything sounds.
This is a simple step that can save you a lot of time and hard work.
I hope you found this information useful!
See you on the next one!