In the thirty or so years I’ve been working in music I’ve always worked exclusively in stereo and as far as I am aware nothing I’ve worked on has ever been mixed in a surround sound format. I’ve been interested in working in surround though, especially as Dolby Atmos becoming more prevalent (Apple announced Dolby Atmos support for Apple Music a few weeks ago). I wanted to investigate moving my studio from being exclusively stereo to also support a surround sound format. This article discusses that investigation. 

My main issue with moving to a surround sound format is ‘what version of it do implement?’. There are a number of different formats with 5:1 being probably the most common. But should I instead go to 7:1 or one of the ‘object-oriented’ formats such as Dolby Atmos in 7.1.4? I’ll explain a bit more about the available formats a bit later but for the purpose of this article I decided to go for a relatively simple 5:1 set up where I have three speakers upfront in Left, Centre, Right positions and two rear speakers, Left Side and Right Side, plus of course an LFE channel.

The second issue is ‘what speakers do I use?’ (And where do I put them?)

I have a few different sets of monitors in the studio- Kii Three’s, ATC SCM45a’s and a set of Neumann KH80’s that sit on the Eurorack desk. Whilst I ‘could’ make up a set of 5 speakers from that they wouldn’t be particularly balanced and I wouldn’t want to mix on them.

I didn’t have immediate access to these but I had something better, a connection to German manufacturer EVE Audio, by way of my previous reviews of the SC305, SC3070 and SC4070 monitors. 

EVE Audio graciously loaned me a set of five SC3070’s for the purpose of the article and I cannot thank them enough. I love the smooth, flattering sound of the SC3070’s and they are neither too big nor too small for my room. They were exactly what I needed. To cut down on shipping costs I used my own subwoofer, a Tannoy TS10, as part of the configuration.

I’ve also made a bit of an investment in my studio recently by purchasing a Trinnov MC8 Pro Speaker Processor and Room Optimizer. A few weeks ago I was lucky enough to review the Trinnov DMON12 Pro and was blown away by the quality of the room correction, it easily surpassing anything I’d used previously.

My decision to purchase the Trinnov MC8 Pro rather than the DMON12 Pro was largely based on my current usage and its ability to be expanded beyond the current capability of 8 channels should I move to Dolby Atmos. More on that later.

As it happened the Trinnov in combination with ’s wonderful SC3070’s proved to be everything I needed to get up and running, listening and mixing in surround. 

Let’s get into it.

Formats Explained

Pro Tools allows for a number of different surround sound formats: stereo, LCR, Quad, 5.0, 5.1, 7.0, 7.1, 7.0.2, 7.1.2 etc.

I imagine most people will be familiar with what 5:1 means but in case you aren’t the 5 in 5:1 means the number of speakers positioned at head height, three at the front (left, centre, right, left rear and right rear). The 1 represents the LFE or ‘low-frequency effect’ channel, sometimes erroneously referred to as the ‘subwoofer’ channel. In 7.1 the left and right rears are moved to the side (LSS/RSS or left/right surround side) and two rear channels (LSR/RSR left/right surround rear).

Formats with three digits, such as 7.1.2 or 7.1.4 add top or height channels, two or 4 respectively and are often seen in ‘object based’ surround sound implementation such as Dolby Atmos.

As this exercise was an initial investigation to listening and mixing in surround sound I decided to stick with a simpler format of 5:1. Going directly from stereo to Dolby Atmos would have massively complicated things, requiring a substantial change to my studio environment. I may (meaning probably will) end up going to Dolby Atmos mixing, every indication is that the industry is heading that way. But not yet.

Why Move From Stereo To Surround?

For the most part, this article was borne of curiosity about what it would be like to mix in a surround sound format. I don’t have any immediate business need to do so, none of my clients or musical endeavours are demanding that I do it. Studio methodologies evolve over time though, and surround sound seems to be something that I needed to get familiar with, especially with Apple’s recent announcement that Dolby Atmos is coming to Apple Music.

Necessary Components

Other than the SC3070 monitors provided by Eve Audio I needed stands to put them on. Fortunately, I had a spare set of speaker stands from my other room which was packed up due to Covid. Of course, I needed sufficient outputs from my audio interface to feed the monitors. I was able to borrow 6 outputs from my Avid MTRX. Other than power and audio cables, that was it. 

Monitor Installation and Placement

Monitor placement for a stereo set is fairly simple, where you form an equilateral triangle between the speakers and the listening position. With surround sound, more speakers equals more complexity. Fortunately, an excellent document exists entitled ‘The Recording Academy's Producers & Engineers Wing Recommendations For Surround Sound Production’ on the Grammy website which walked me through not only optimal speaker placement but the correct configuration of the system overall. This document, compiled by Howard Massey, was written by some of the biggest names in audio production such as Chuck Ainlay, Joe Chiccarelli, Bob Clearmountain and others.

The recommendation for placement is to have all the monitors equidistant from the listening position, arranged around an imaginary circle. As the figure below indicates (taken from this document) you can see that the middle speaker would be placed centre to the mix position with the left and right speakers approximately 30° on either side of it. The eagle-eyed will notice this is the same recommendation for the left and right speakers as you would have for a stereo pair. The recommendation for the left side and right side speakers is they be between 135° to 150° from the centre line. The recommendation is that all speakers be between 6.5-7.5ft from the listening position.

My 6x4m studio space is crammed with gear, so precise positioning wasn’t possible.

I was able to put the rear speakers around 145° from the centre line, 6.5 ft from the listening position but the front three monitors could only be placed at a maximum of 6 ft away. If I was setting these up permanently I would probably reposition my studio desk to allow an extra 12 inches of distance between the mix position and the front monitors.

Interface Reconfiguration

With the monitors in placed, I turned my attention to reconfiguring and labelling my audio interface to suit.

I connected the Avid MTRX’s 8 analogue outputs to the Trinnov via a DB25 cable and then the monitors to channels 1-6 of the Trinnov in the format L,C,R,Ls,Rs,LFE (corresponding with channels 1-6). Whilst the Trinnov allows for different output ordering it made sense to maintain this channel order all the way through. 

I then labelled the outputs in DADMAN, the control application for the Avid MTRX interface, following the same ‘L, C, R, Ls, Rs, LFE’ channel order.

I also needed to define and label the outputs from Diglink/HDX in DADMAN to reflect the channels that I want to define as outputs in the Pro Tools IO page.

The next step necessary was to check the analogue channels in the Trinnov feeding monitors match the same format outputted by the Avid MTRX. I then used the Trinnov 3d microphone to calibrate the room.

As you can see in the picture below the Trinnov found quite a lumpy low end, which was corrected by the unit. I’ve supplied the graphic just showing the stereo channels, the centre and surround channels show a similar distribution.

Monitor Calibration

I should speak about monitor calibration as part of the installation process. Other than correct placement, monitor calibration is a crucial process that should be undertaken in order to provide the best mixing capability for any studio.

Manual monitor calibration for surround is essentially the same process for a stereo system, you simply have more channels to do. The calibration microphone is placed facing forward in between the left and right speakers (or in a surround sound format, at the centre speaker). A reference level of 85dB is often used, where pink noise is sent at 0 vu, first to the left front speaker, raising the level until all bands of an RTA meter read 85dB. The process is then repeated for successive speakers.

(See section 3.6 in the ‘The Recording Academy's Producers & Engineers Wing Recommendations For Surround Sound Production’ for more information on this process.)

I didn’t have to do this though, because the Trinnov MC8 Pro level matches as part of its calibration process. This is a great time saver.

Pro Tools IO Reconfiguration

The next task was to reconfigure Pro Tools to output audio in 5:1. This can be done in the Setup/IO window. Select ‘New Path’ and then change new from ‘mono’ to ‘5:1’ and label the output. You can select multiple different types of Path Order, as discussed earlier I stayed with ‘L C R Ls Rs LFE’.

Once I’d done this I was able to open a couple of my demo sessions I use for testing gear and convert them over to surround, simply by changing the output path from ‘Stereo Out’ to ‘5:1 Out’ and then saving with a new file name. Once this has been done the Pro Tools mixer will appear slightly different and you are able to open a control window on each channel as pictured below:

Here you can see a stereo bounce of some drums, as it is a stereo channel you have the ability to position the left and right channels independent of one another. Mono channels have just one side of this window and you can position the track anywhere in the surround field.

Any Issues?

Frankly, precious few-well… none, others than a case of PEBKAC- ‘problem exists between keyboard and chair’… old IT support joke.

That is partly because EVE Audio was able to furnish me with an excellent set of identical monitors so swiftly but also partly because the usual calibration process one would undertake to level match all the monitors in a surround sound set up was so easily done as part of the Trinnov calibration process.

In the initial stages, I didn’t maintain a consistent channel order and had to manually reorder the channels in the Trinnov, which fortunately it allows you to do. Once I realised my mistake it was easy to rectify. Otherwise, it has been plain sailing.

Conclusion

This has been a very interesting process to undertake. I’ve been working in surround for the best part of a month now and it has largely become second nature to me. It feels like a stepping stone though. 5:1, as a format, is probably not something I need to be working within the long term, but I can see Dolby Atmos as being a strong requirement quite soon. I am very excited by the prospect of being able to work in Atmos but in order to do so, I’ll need to do a bit of a studio rewire and decide on which monitors I’d want to use for the height speakers. Mounting/hanging those speakers will be a non-trivial amount of work, I will need audio and power to be wired into the ceiling, plus the necessary supports in place. I’d like to thank Eve Audio, Paul Mortimer at Emerging, UK and Trinnov for their support and help throughout this process.