This is a concept I got familiarized with not so long ago. I always used to add vocals as harmonies to make everything sound better, but I never really used to double track vocals.
Since I assume that many of you reading this post are looking for ways to improve the quality of your double tracked vocals, I’m going to do my best to teach you everything I learned on this topic.
First of all, let’s take a look at what Double tracking actually is;
Double tracking a vocal is the process where you duplicate a second vocal on top of the main one to give it more thickness or to widen it.
This can be achieved by either recording a second track on top of the first one or by using an Automatic Double-Tracking Plugin.
One thing to note is that no matter how good the singer is, there will always be differences between both takes, resulting in a slight pitch and timing difference which will give it that distinct characteristic.
Should you double vocals?
It all depends on what part of the song you plan on doubling the vocals.
I wouldn’t recommend it in the verses because they can end up sounding a bit muddy, but if the chorus is lacking a bit of strength and body then you absolutely could use double vocals.
How to mix Double Vocals
You could use plugins to thicken the vocals, but EQ, Compression, Delay and Reverb, will only get you so far. Using a Doubled vocal is, however, the best way to fatten up the sound, especially if the singer can deliver a well sung double track.
After recording a doubled vocal track, you then can proceed to use all the plugins you want on them to enhance the sound even more.
Since you’re mixing two vocals, you can’t really treat them like one. If you center both you will get a similar effect to using a chorus, which in some cases might be the sound you are going for, but just know that this isn’t the most common way to do it.
I find it best to pan both vocal tracks between 10% and 30% right and left, you don’t necessarily want to pan both exactly the same amount.
In some cases you are going to pan one 20% to the left and the other 10% right, this all depends on what other elements you got going in the mix.
The one that is more centered would generally be the main vocal track, which will be the loudest. Then, bring the second one up until it’s just loud enough to be perceived, no more than that.
Important note: This is definitely not set in stone, these are not rules but guidelines, every song is different so play around with it and see what works best.
One tip I can give you is to use automation to enhance certain parts of the song, like the choruses.
Panning both vocals left and right during the chorus will give the mix a much bigger sound, increasing the stereo width. This works great when you want to generate some build up.
Imagine your song has a verse, a pre-chorus and then the chorus, what you could do is use the vocals to help with that build up by slowly panning them out.
How to fix a double tracked vocal part
If you are really double tracking, by this I mean recording a second or third take and not using doubling software, then it’s more than likely that at some point of the take there will be something that needs fixing.
Imagine you recorded two perfect takes, but just one or two words need to be corrected on one of them, there is a simple fix for this.
Simply copy and paste that part of the clip from the perfect track into the other one. Now, all that’s left to do is to delay it anywhere from 20 to 40ms.
This will be enough to give it that doubling effect.
How to fix notes that don’t end at the same time
Doubling a vocal means that they should sound as similar as possible in every way, but if one of those takes ends a bit later than the other, it can ruin the whole thing.
If the take you recorded is perfect in every way except right at the end, there’s two really simple ways that you can fix this.
The first example is if the note that needs to be fixed is longer than the correct one; Here all you need to do is use a fade-out at the end, making that note die down a little sooner.
The best way to do this is to group all vocal tracks together and use a common fade on all of them.
The second example is when the note that needs to be fixed is longer; This one’s a bit more complicated since you will need to stretch that specific part.
Split the clip before the last word and use the stretch function, which almost every DAW has, to lengthen that word. This may end up sounding a bit less natural.
A way to avoid this is by only splitting and stretching a part where the note is being sustained, you stretch that region, and then using crossfade you create a smooth transition between those splits.
Use pitch correction if necessary
Double tracking only works if the tracks are extremely similar both in pitch and timing.
If you are having issues getting the singer to record a second track properly, you could always use pitch correction software such as Melodyne and AutoTune to create a suitable secondary track.
It’s best not to go too aggressive with this kind of software, otherwise it might end up sounding unnatural and robotic.
It’s really easy to make small adjustments that give you the rich sound that you need.
One way of doing this is by using pitch correction on the second track you recorded to make it more in tune with the first one.
The other way is by duplicating the first track, lowering the pitch anywhere from -10 or -15 to -30 cents, adding a bit or delay and modulation and mix it in at a lower level than the lead vocal track, it should only thicken up the sound.
More on this a bit later in the post.
Use Pitch Correction Software to create Harmonies
To be honest, I try not to rely on pitch correction software, especially if I’m the one singing. But there are times when I want to sing a harmony and there’s a couple of notes that I can’t reach, be it too high or too low.
If you force this, two things can happen; either you manage to hit the notes, but they don’t sound at all natural and how you want them to sound, or you could strain your voice.
If you use pitch correction the right way, it could help you “hit” those notes by simply fixing them with the software.
This will allow you to choose the key of the song based on how well you can sing most of it and then simply use these correction tools to help you out with the difficult parts.
Also, let’s not forget that creating harmonies with pitch correction will sound completely different to the real thing, if you so desire. It can definitely open up a lot of doors and help you achieve a greater end product.
Usually the way to do this is;
- Duplicate your lead vocal track
- Open your pitch correction software
- Solo both tracks
- Adjust the notes on the second one to create the harmony
Use Double tracking to accentuate phrases or words
While double tracking is most commonly used to thicken up the vocal sound on choruses, to give them more strength and power, another interesting way of using double tracking is to emphasize certain words or phrases.
This is something that is done quite a lot in rap songs when there is one word that you really want to emphasize, they tend to really exaggerate it.
A cool way of doing this is by dropping out the center vocal and using two separate vocal tracks panned to the sides.
Automatic double tracking software
Of course, if you don’t want to go through all the trouble of recording the second or even third vocal tracks, since this can take huge amounts of time because each track needs to be as identical as possible, then you could try some of the plugins out.
Most of them aren’t free, and they actually sell for quite a bit, but they might be worth it if they save you a lot of time.
Note: They are great, but it’s not identical to the real thing. However, if the performer isn’t able to record a double track properly, you will be much better off using this kind of software.
Here are a couple of them;
Vocal Doubler by Izotope: This one is free, you just need to enter your e-mail and you are good to go. I’d start with this one and see how to goes before purchasing another one.
VoxDoubler by Sonnox: This is a great piece of software but it costs £69. It has a trial period though, at least you can check it out before you buy.
Doubler by Waves: Make sure to check it out, it only sells for $29.
Do it yourself; Use time- and pitch-shifting
Another way you can create a similar effect to the double tracked sound is by duplicating the vocal track and using delays and pitch shifter plugins to achieve this. If you don’t do this, all you will be achieving is that the vocals will sound louder.
To produce an authentic stereo image, there needs to be some time and pitch difference between the original and double.
First, you copy the vocal on to a second track.
Delay it by a couple of ms, here you need to listen and see what sounds best, but 20 to 80ms seems to be a good range!
Next you need to pitch down the track, something along the lines of -10 to -30 cents should be fine!
If you want to use three tracks and not just two, the third one, as a rule of thumb, should be shifted up the exact same amount as the second one was shifted down.
You could try modulating the pitch, this could open the door for a variety of new flavors.
Once you did all this it’s time to mix them together; It’s very important that the duplicated vocals don’t overpower the first one, they are only there to enhance it and give it some thickness, it should be very subtle.
If you want to make it even more subtle you could apply EQ to the double.
Here you should be focusing on cutting some specific frequencies that are more prominent, reducing the presence of the double, which will help it blend more.
Fix Inhale sounds that occur at different times
Dealing with inhales when you are dealing with two or more simultaneous tracks isn’t really that difficult but essential to fix, because if they happen at slightly different times then that whole part won’t sound the way you want it to.
How to fix this issue?
I find that there’s just one way of fixing this; simply cut out all the inhales that are not aligned correctly and use a crossfade to make the transition subtler. The inhales that you kept will also help out smoothing the transition.
Also try playing around with fading in to the inhales, or just lowering the volume of that particular one a bit if it’s too prominent.
Use Vocal Formant Shifter Plugins
Vocal formants determine the timbre of your voice, roughly put it’s when you can sing the same note but making it sound completely different each time.
For instance, you can get a nasally sound which is very bright, or a very low and dark sound while always maintaining the same note.
It’s very similar to slowing down or speeding up a vinyl record that’s being played. Sure, the pitch changes too when you do this, but when you speed it up the vocals would end up sounding like Mickey Mouse.
Vocal Formant shifter programs give you this kind of sound, which if you use it on your second or third vocal can do great things for your mix.
You could make your second voice bright while making the third one dark and low.
You can even automate them to change from bright and nasally to a darker and lower sound.
Here’s a link to a Youtube Video where you will be able to appreciate the effect:
I’ll leave you a couple of links to some free software that can achieve this, otherwise you could use Melodyne and AutoTune, both of which tend to be the go-to.
This in an extremely important step, not only for mixing doubled vocals but for mixing in general.
It’s good practice to set up a specific channel for effects where you then can run as many of your audio tracks through it as you like, applying the same effect to all tracks.
This not only makes it a lot easier to mix all the tracks, but it also saves a lot of processing power from your PC, since adding effects to every track, especially time-based ones, is a lot more CPU intensive.
Another pro to using effect busses is that every track will have the same reverb/delay, which will make everything sound as if it was recorded in the same room giving it a common acoustical space.
Like I said earlier, this shouldn’t be taken as a rule you absolutely need to follow, since sometimes you’d want to give your second or third vocal tracks a distinct characteristic.
However, you usually do this by using EQ, compression, distortion, etc. whereas reverb and delay tend to be used as sends since you want the same timing and room characteristics applied to all tracks.
Learning how to double track vocals and then mixing them isn’t that easy, it’s going to take you some practice, but I think that it’s worth the effort.
Since this technique is mostly used to thicken the vocal sound please remember to be subtle, the listener should not be able to hear two distinct voices, it’s used to enhance another vocal track.
Also, I find that this tends to be easier to perceive on Headphones, so remember to switch between them and your Monitors to achieve the best result.
One last and final point is that you need to check the mix in mono. Panning makes everything sound great and you can’t really perceive phase issues, so remember to constantly switch to mono to avoid bigger headaches down the road.