Mixing in 5.1


 

I've been recently learning about and sort of discovering the world of surround sound, and more importantly, what it means to achieve a quality surround sound mix. While most consumer hi-fi, computer speakers or home entertainment systems are not configured for a 5.1 listening experience, 5.1 is still an interesting creative endeavour, and aside from the most obvious and somewhat essential application in theatre sound, it can also be utilised to create immersive musical experiences. I had every intention of going into my first 5.1 mixing session and up-mixing a my Arctic film trailer project from earlier in the tri. However, due to a slight slip up from myself, I wasn't able to work on the post production project I had hoped to and instead I chose to re-mix a song of mine into surround sound.


In this blog, I want to go through what some of the industry standards are when it comes to theatrical mixes, and how this changed my approach to the mix up into 5.1 I did for my track.

 

Industry Standards

Let's briefly talk about the general practice of operating in a surround environment for film and television, I'll see if I can find any guidelines for mixing 5.1 with music as well, but I imagine it's a more creative endeavour and therefore probably has less rules associated.


I'll pick a couple of points that I come across that I think I can relate the to the practice that I undertook and also some parallels I can draw to the film I watched.


Don't Rely on the Sweet Spot

With any speaker set up there's a "sweet spot" at which all the speakers line up evenly with the ears of the person listening. If you're in the sweet spot, you're hearing all the speakers at their intended volume and position, outside of the sweet spot you'll have a different reference point for each speaker, which changes depending on your position in relation to each speaker. In a 5.1 set up, this is somewhere in the centre of all the speakers, and if we're thinking of a theatre audience, not everyone is going to be sat smack bang in the middle of the speakers, which is exactly why a theatrical mix shouldn't have focus on this ideal position.


"Take an opportunity to stand up and walk around during your mix session, sitting in a few different places and observing how your mix translates. Is the dialogue still clear? Does that dramatic fly-over effect translate from the back of the room? Did all the violas disappear when you moved to the left side of the room?" (iZotope, 2016).


Making sure the over all purpose of a mix translates to an audience is key; if you want the audience to experience a particular sound in a particular way, then make sure the entire audience is going to experience it that way.


Manage the Centre Channel Differently to the"Phantom Centre"

In a regular stereo mixing environment, the "centre" of your mix is created by having an equal amount of volume coming from both the left and right speaker. If a mono sound source is played on a stereo system then you will get the effect of it being directly in the centre because it's playing at equal power from each speaker. In a 5.1 system, this rule still applies with the left and right speaker, but with the addition of a centre speaker. To relate back to my previous point;


"There’s also an inherent problem with a phantom center in that it only works for listeners in or near the sweet spot; someone seated close to the left speaker, for example, will hear the signal as coming from that speaker alone. So if someone moves around the room, signal coming from the real center channel will remain fixed, while phantom center signal would shift, skewing the soundstage." (Waves, 2017).


Considering also the consumer environment where most people will only have stereo speaker configurations, 5.1 mixes should be prepared for what's called a "fold down", where all of the speakers are summed into the two left and rights.


"When encoding for Dolby Digital, MLP, or WMA9, the Center channel downmix

coefficient should be set to -3dB in relationship to the Left and Right front

channels. However, the rear channel coefficients are largely programdependent. Many of today's surround productions are mixed with an "in the

band" perspective. (See section 3.3.1) In those instances, the rear channels

must be at the same level as the front left and right channels. However, the rear

channels may be lowered -3dB if they contain only ambience or audience

material."


(P&E Wing Recommendations for Surround Sound Production, 2004)


I've also been told that most 5.1 mixing engineers will keep most, if not all, of their dialogue in the centre channel so that it can be easily dubbed in different languages for international release. As the above point suggests, if an audience member is sat to the left of the centre speaker then they're going to perceive every bit of dialogue from their right. It's possible however that a separate mix could be made with dialogue exclusively in the centre, where as English theatrical mixes could be mixed with which ever the dialogue wherever the engineer wants it.


Get Creative, But Don't Over Do It

The fact that mixing in 5.1 gives you a whole other 4 (including sub [.1]) speakers to work with means you can get pretty creative, and do some interesting things with the panning in your mix. But once again, it's important to remember the viewer and what they have to essentially sit through while they watch your film, or listen to your music in surround.


"Although you may like a surround effect that spins your head, and it may be just what your

production needs, repeating the move dozens of times will usually tire the listener. The key to a good surround mix is subtlety. Don’t draw attention to your techniques. The listener should never be distracted from the screen by surround effects. Loud, obnoxious, or out of place effects detract from the production. Keep it fun, but tasteful." (Dolby Surround Mixing Manual, 1998)


The important thing to remember is that your audience is watching a film, and that means they need to be looking at the screen, not turning around because they thought a sound coming from the rear of your mix was actually in the theatre.

 

Reflecting on Industry Standards and My Own Work


Here's a reference stereo mix of the song I chose to up-mix into 5.1. I'll now go through a couple of the industry standards I mentioned, why I followed them, or why I ignored them.



That Sweet Spot

I have recently been to the cinema and had the pleasure of watching the new Tarantino film, Once Upon a Time, in Hollywood, and I noticed a few interesting mixing choices in the surround sound that made me question these industry standards, and being the annoying sound engineer I am, I couldn't help but constantly mention to my girlfriend the fact that we weren't sat in the sweet spot. Instead we were sat off to the right, up the back of the theatre, and the first thing I noticed about being up the back was the lack of level in the over all mix (one of my previous blogs talks about the reason for theatres turning the volume down on their films). I couldn't help but want the over all level up juuusstt a bit, and the way the speakers were calibrated created a sort of unfortunate delay between the front and the back. Regardless of this, I think there was a few interesting things in this film that I appreciated but can see why it wouldn't be standard practice as mentioned above.

The scene in which Rick Dalton and his stuntman, Cliff Booth, which a scene from Rick's latest TV show together, the camera is mostly centred on the television screen, as if the audience is watching it with the characters. The two characters have a kind of running commentary during this scene, and in an attempt to place the audience members into this scene, the dialogue is hard panned to the back left and back right of the cinema in relation to the position of each character. I could definitely appreciate the creative approach, but I can't help but feel I didn't get a lot of the dialogue from the left channels as much as I did from the right. I'm sure that sitting right in the middle this would have been a really cool effect, but this is again why the entire surround imaging should be taken into consideration.


During my mix, I remembered this sort of uncomfortable feeling in the cinema and tried to avoid creating a similarly confusing experience for whoever would listen to my mix. I of course wanted the mix to be interesting and a little bit off the wall due to the slightly overwhelming nature of the music, but I still wanted it to be enjoyable from all aspects of the surround field. This meant I had to move around during my mix and because of this I ended up making a couple of creative choices. There are two main drum breaks that make up the basis of my track, and they are layered with each other to create the full drum line so it's a bit hard to tell in the regular stereo version that they are separate, which was the intention. In the surround mix, I left the main break in the front speakers during the intro, but the second break jumps into the back left and right instead of in the front. This is a pretty extreme panning choice that gives an individual listener with a small set up an interesting effect, and an audience in a larger room a different effect for each person. People down the front will hear the first break with the second coming from the rear, people in the middle will get the perspective of both, and people up the back will hear the distant first break with the second right behind them. This is all of course a very creative choice, but one that I thought was interesting, and worked well in breaking up the density of the track.


Centre and Phantom Centre

In regards to the drum breaks, I felt like i had to sort of consolidate them during the chorus, and add a bit more weight behind the main break. I decided to make a duplicate of the main drum break and put it in the centre channel only with a slight reduction in level, to reduce phase issues and doubling in level for fold downs. I also brought a duplicate of the second break all the way to the front so that the beat would feel more complete during the chorus, but left a it doubled in the back speakers for an immersive effect. As a general rule in electronic music production, you want the foundation parts of your track (e.i. kick, snare, bass, etc.) mono, or at least as close to the centre as possible so that you can try and reduce phase cancellation and obscurity in the mix, especially when it comes to this kind of genre. The drum breaks were brought into the original Pro Tools session I was working from as consolidated tracks so I couldn't separate the kick and snare from them, but again, I overcame this by putting a version of the first break in the centre speaker. I decided that the centre channel would give me a great opportunity to completely centre the kick and the snare in the second half of the track and to me, they sounded a lot clearer and punchier when separated from the left and right channels. I left the bass in the phantom centre however, because the sub (0.1) would be able to keep the bass frequencies positional.


Over Doing It, Creatively

So yeah, about that bit where I mentioned you shouldn't go over the top with creative panning choices because it can be really disorientating, well, I went a little over the top. Besides what I've already mentioned there were a couple of other things I did with this mix that I might have over done a little, and I'll tell you why. To start of with, I really wanted some of the reversed, reverby pianos to sort of travel around slowly as they played, just to create a little bit more intrigue in the track. So I had them pan slowly around all the speakers in a larger circle, so they kind of travel the entire surround image while the intro drums are playing. I mean this definitely isn't too over the top as it kind of makes sense contextually, but it got me going on the whole "panning-everything-so-it-spins-around-the-room" train, and I started on some of the other elements. The arpeggio synth that appears around the middle and closer to the end of the track, pans suddenly from the front left, to the front right, to the back right, to the back left and then repeats this cycle, on beat throughout the chorus. I also had an extra break in the stereo version that panned left to right throughout the second part of the chorus, which I ended up panning back and forth front to back as well. This all kind of only happens in the second part of the chorus so it's not like the listener will be inundated with ridiculous panning throughout the track, and I think it adds the desired, frantic and somewhat disorientating effect I was looking for.

 

How It All Went

I can't be unhappy with my finished project, but I definitely can do more than just pan a few elements into unorthodox panning positions. Truth be told I have done a lot more than I've hinted at in this blog, but the points I have made are the ones which I think are most relevant and easily discussed regarding industry standard. I would like to approach my next mix in 5.1 from the first mix I do, rather than doing a stereo mix and then up-mixing, because there's no doubt my approach will change if I'm mixing something that is intended to be folded down into stereo later. I'm over all pleased with what I have discovered and am glad I had a chance to get my hands dirty in some surround sound mixing.

 


Bib:


iZotope. (2016). 6 tips for mixing in surround. Retrieved from https://www.izotope.com/en/blog/mixing/6-tips-for-mixing-in-surround.html


Tutorial - The DOs And DON'Ts Of Mixing In Surround | Pro Tools. (2018). Retrieved from https://www.pro-tools-expert.com/home-page/2017/12/20/tutorial-the-dos-and-donts-of-mixing-in-surround


Recommendations For Surround Sound Production. (2004). Retrieved from http://www2.grammy.com/pdfs/recording_academy/producers_and_engineers/5_1_rec.pdf


Dolby Surround Mixing Manual. (1998). Retrieved from http://www.idea2ic.com/Manuals/dolbySuround.pdf