In this pro mixing tutorial I will reveal a pro technique you can apply in order to enhance the perceived "depth" of the stereo image of your mix, "stereo fullness" would be a different way of describing this.
So let's dig right in, I will describe a few key technical details and explain how it works.
When you record, you record all sound sources at near full signal capacity, for two reasons. The first is that you want as much of the natural modulation and decay captured of each sound source, the second is that you want to provide the mixing engineer full freedom in how he/she then decides to balance it by assigning full resolution to each sound source in the mix as if they were all equally important. This does not mean that you don't alter the signal during tracking, you do, but you do so on the recorded signal just to ensure you are recording successfully. Thanks to having all of this modulation and decay richness present in the recorded tracks, you can then spread that resolution across the stereo image in order to provide a lot of details between the left and the right speaker. When this type of content has good phase quality, you achieve what is the foundation of a high quality stereo image.
But in order to then improve the stereo image from there and create added sense of stereo depth, you need to create the following contrasts:
- Contrast within center (both mono and stereo tracks panned center, frequency contrast)
- Contrast within side
-- Contrast within L (both mono and stereo tracks panned towards L, frequency contrast)
-- Contrast within R (both mono and stereo tracks panned towards R, frequency contrast)
- Contrast between center and L (pre-delay X ms, frequency contrast)
- Contrast between center and R (pre-delay Y ms, frequency contrast)
- Contrast between L and R (achieved by the above, frequency contrast)
So, essentially what happens is that each "component" that makes up the total perception of the stereo image, gets additional contrast and it is the combination of all of these contrasts that then make up the additional stereo depth. So what you can do is to solo all of these components and work towards enhancing the contrast of each in isolation by then thinking of time, frequency, mono vs stereo, panning, gain when you improve each. This then combines into a full sounding stereo image.
Technically what you can do is that because you have all center panned sound sources grouped to a single stereo track and all side panned sound sources grouped to a single stereo track, you can then route the side track to a separate track for L and a separate track for R and hence be able to dial in the pre-delay in this way. This means that there is a small time difference between the sound sources in the center and the sound sources on the side, as well as between the sound sources on each side. And because you can then apply zero-phase EQ on each of these sides, you add more contrast between the center and the side as well as between L and R. The two separate side tracks you can then combine into a stereo track again afterwards for post-mixing and mastering.
Please note that it is good to solo each side in mono mode when you monitor, so that you can hear the frequencies on both speakers and hence get a more full insight into the frequencies on each speaker. When you tune the center vs L and center vs R, you can bring the L or R into mono, leave the center in stereo and then monitor that combination of course having the other side track muted. In this way you can hear more clearly how each side contrasts with the center.
During post mixing when you gain stage the mix to an optimal level for mastering, which is quite near the final level but leaves some room for additional gain staging, please then notice that the peak information on the side is very critical for a high quality sounding stereo image, the peaks on the side should cut through the peaks on the center a little, if the peaks in the center are well rounded you can also stay a bit more gentle with the peaks on the side, meaning you don't have to push as much signal in order to make the peaks cut through on the side, this then makes the side more pleasant.
And don't forget to monitor the SIDE component in solo, then I don't mean the side panned tracks, but the SIDE component of the mix from the perspective of M-S. The SIDE component should be well segregated, contain very low amounts of noise especially in the low end and have quite a lot of mid frequencies. (which opens up the mix) If you have long reverb inside of the side component, it has to be super clean/transparent on the signal. A Bricasti reverb can do that.
When you do this it is good also to use a frequency/phase correlation meter and of course don't forget to balance the L and R so that the stereo image as a whole is absolutely center focused and does not drag to one side in the lows, mids or highs. If you focus the bass more towards the center you can dial in some additional upper low mids on the side, this makes the mix a bit more full/big sounding. Ensure L and R balance across the process as a whole, not only in the final stages of mastering.
A slightly more advanced approach that you should experiment with is to route the side panned tracks to two side stereo tracks and leave one of those without any pre-delay (unique sound sources on each of these side stereo tracks), that could for instance contain percussion and other rhythm intensive content that you do not want to get time altered. You can still end up with a single stereo track for the side for post-mixing and mastering, but in this way you can separate the sound sources on the side slightly more, get a slightly better sounding groove and with an additional volume fader for balancing and automation you can achieve more, for instance by compressing the non-rhythm side track slightly more the percussion peaks now become more dominant which might add to the groove but also create some room for lowering gain on it in order to create a softer attack on the side without losing too much of the peak information which is required for a full sounding stereo image. A typical example of when something like this would work would be to keep the cymbals on the non-pre delayed side and have mild (slow attack, long release, low ratio, mild threshold, soft knee) or no compression on that, instead of having compression on either the whole side only or even worse only on the whole mix which could consume the beauty of the cymbals entirely.
What this boils down to essentially is that for the group tracks you avoid compressing too many sound sources too hard at any stage. That makes the mix more vital sounding and that vitality is delivered in the form of a full sounding stereo image.
What I also do is that when all of this is dialed in the phase might have become slightly damaged overall or it is simply not as effective as it could be in this particular setup, then I apply phase auto-alignment on the individual track level (excluding the rhythm element) with very low latency. Depending on the effect that happens to have on the content, it might have a finalizing effect on the stereo image in which it all falls into place. Proper A/B is what finally determines whether that has a desired effect or not, but it is worth a try. Since it is applied on the non-rhythm elements it can have the effect of making the rhythm element more tight and more dominant which may or may not be desired.
So let's dig right in, I will describe a few key technical details and explain how it works.
When you record, you record all sound sources at near full signal capacity, for two reasons. The first is that you want as much of the natural modulation and decay captured of each sound source, the second is that you want to provide the mixing engineer full freedom in how he/she then decides to balance it by assigning full resolution to each sound source in the mix as if they were all equally important. This does not mean that you don't alter the signal during tracking, you do, but you do so on the recorded signal just to ensure you are recording successfully. Thanks to having all of this modulation and decay richness present in the recorded tracks, you can then spread that resolution across the stereo image in order to provide a lot of details between the left and the right speaker. When this type of content has good phase quality, you achieve what is the foundation of a high quality stereo image.
But in order to then improve the stereo image from there and create added sense of stereo depth, you need to create the following contrasts:
- Contrast within center (both mono and stereo tracks panned center, frequency contrast)
- Contrast within side
-- Contrast within L (both mono and stereo tracks panned towards L, frequency contrast)
-- Contrast within R (both mono and stereo tracks panned towards R, frequency contrast)
- Contrast between center and L (pre-delay X ms, frequency contrast)
- Contrast between center and R (pre-delay Y ms, frequency contrast)
- Contrast between L and R (achieved by the above, frequency contrast)
So, essentially what happens is that each "component" that makes up the total perception of the stereo image, gets additional contrast and it is the combination of all of these contrasts that then make up the additional stereo depth. So what you can do is to solo all of these components and work towards enhancing the contrast of each in isolation by then thinking of time, frequency, mono vs stereo, panning, gain when you improve each. This then combines into a full sounding stereo image.
Technically what you can do is that because you have all center panned sound sources grouped to a single stereo track and all side panned sound sources grouped to a single stereo track, you can then route the side track to a separate track for L and a separate track for R and hence be able to dial in the pre-delay in this way. This means that there is a small time difference between the sound sources in the center and the sound sources on the side, as well as between the sound sources on each side. And because you can then apply zero-phase EQ on each of these sides, you add more contrast between the center and the side as well as between L and R. The two separate side tracks you can then combine into a stereo track again afterwards for post-mixing and mastering.
Please note that it is good to solo each side in mono mode when you monitor, so that you can hear the frequencies on both speakers and hence get a more full insight into the frequencies on each speaker. When you tune the center vs L and center vs R, you can bring the L or R into mono, leave the center in stereo and then monitor that combination of course having the other side track muted. In this way you can hear more clearly how each side contrasts with the center.
During post mixing when you gain stage the mix to an optimal level for mastering, which is quite near the final level but leaves some room for additional gain staging, please then notice that the peak information on the side is very critical for a high quality sounding stereo image, the peaks on the side should cut through the peaks on the center a little, if the peaks in the center are well rounded you can also stay a bit more gentle with the peaks on the side, meaning you don't have to push as much signal in order to make the peaks cut through on the side, this then makes the side more pleasant.
And don't forget to monitor the SIDE component in solo, then I don't mean the side panned tracks, but the SIDE component of the mix from the perspective of M-S. The SIDE component should be well segregated, contain very low amounts of noise especially in the low end and have quite a lot of mid frequencies. (which opens up the mix) If you have long reverb inside of the side component, it has to be super clean/transparent on the signal. A Bricasti reverb can do that.
When you do this it is good also to use a frequency/phase correlation meter and of course don't forget to balance the L and R so that the stereo image as a whole is absolutely center focused and does not drag to one side in the lows, mids or highs. If you focus the bass more towards the center you can dial in some additional upper low mids on the side, this makes the mix a bit more full/big sounding. Ensure L and R balance across the process as a whole, not only in the final stages of mastering.
A slightly more advanced approach that you should experiment with is to route the side panned tracks to two side stereo tracks and leave one of those without any pre-delay (unique sound sources on each of these side stereo tracks), that could for instance contain percussion and other rhythm intensive content that you do not want to get time altered. You can still end up with a single stereo track for the side for post-mixing and mastering, but in this way you can separate the sound sources on the side slightly more, get a slightly better sounding groove and with an additional volume fader for balancing and automation you can achieve more, for instance by compressing the non-rhythm side track slightly more the percussion peaks now become more dominant which might add to the groove but also create some room for lowering gain on it in order to create a softer attack on the side without losing too much of the peak information which is required for a full sounding stereo image. A typical example of when something like this would work would be to keep the cymbals on the non-pre delayed side and have mild (slow attack, long release, low ratio, mild threshold, soft knee) or no compression on that, instead of having compression on either the whole side only or even worse only on the whole mix which could consume the beauty of the cymbals entirely.
What this boils down to essentially is that for the group tracks you avoid compressing too many sound sources too hard at any stage. That makes the mix more vital sounding and that vitality is delivered in the form of a full sounding stereo image.
What I also do is that when all of this is dialed in the phase might have become slightly damaged overall or it is simply not as effective as it could be in this particular setup, then I apply phase auto-alignment on the individual track level (excluding the rhythm element) with very low latency. Depending on the effect that happens to have on the content, it might have a finalizing effect on the stereo image in which it all falls into place. Proper A/B is what finally determines whether that has a desired effect or not, but it is worth a try. Since it is applied on the non-rhythm elements it can have the effect of making the rhythm element more tight and more dominant which may or may not be desired.
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