5.1 Room Calibration

Last week I was lucky enough to be introduced to A studio I have been fascinated by since I started my audio journey as SAE. I think this was a really great introduction into a new block of the year. We calibrated the room to broadcasting standards. I was interested in this as I have never calibrated a studio before so I thought it would be a great idea to do some further research into surround systems and standards. As well as the importance of studio calibration.

Dolby is one of the worlds biggest sound companies. Many theatres are calibrated to this standard of audio. I took a look at their specs online and as able to find some great resources about their calibration and why they use this method. Okay so let’s take a step back what exactly does 5.1 mean when it comes to surround sound? The 5 part refers to 5 main monitors and the .1 is a LFE (low frequency engine).  Sub frequencies are filtered at either 120hz, 100hz or 80hz and below.

Room calibration is important for studio recordings and for playback in 5.1 so that the entire frequency range is being produced at the same volume. An SPL meter is used to determine this. SPL stands for sound pressure level. You can even get these on your phone they are often used in music venues to monitor the level of music. the reading of the SPL level can be taken by seeding out a pink noise signal and filtering through all the speakers 1 by 1 yo get an accurate reading. In a broadcasting studio and in home theatre surround sound the SPL of all the speakers should be 75Db in C waiting mode. Alll but the Sub. The sub will be given an extra 4db to equate for the lower level of sound respective to the human ear. For instance in a broadcasting studio the sub will be set to 79Db. This is in reference to the ‘sweet spot’. The distance from the sweet spot isn’t so important if what you are mixing is in reference to this spot. The most important element is that angle at which the speakers are placed from this spot. The calibration element really comes into play here. For 5.1 the speakers are angled like this..

The angles at which the speakers are placed are all relevant to getting the best over all sound. The end goal into having all surround systems calibrated in this same way is to ensure that the mix sounds the same on all surround systems. This set up generally won't cause any speaker phasing issues. It is important to check a studio for the distances and angles of the speakers before mixing to avoid this (Dolby, 2018).

These are super basic things I have learnt recently about mixing in 5.1. I am yet to create a project based around this style of mixing however now knowing some of the fundamentals about the sound level I believe that it will help with my next 2 projects. I am planning on mixing some music in 5.1 very soon and heave learnt there are a number of ways to execute this. For instance have the vocal as a stereo spread out the L and R speakers rather than the centre. I am interested to research this more and see just how people have mixed music in surround in the past for concerts and live videos.

Stay tuned or updates on projects I am working on currently this was more just a little over view of some cool tech stuff I learnt this week!

References:

Tools & Media Studio Resources Design Room Calibration | Dolby Developer. (2018). Retrieved from https://developer.dolby.com/tools-media/studio-resources/studio-design/room-calibration/

Mixing in Surround: DOs and DON’Ts | Waves. (2017). Retrieved from https://www.waves.com/mixing-in-surround-do-and-dont

Jackson, B. (2017). Talking Heads in 5.1. Retrieved from https://www.mixonline.com/recording/talking-heads-51-375349