Binaural audio has exploded over the past few years due to Virtual Reality (VR) becoming increasing popular. I know this because it's developed quite a few different names: 3D audio, VR audio, 360 Audio and the latest - and most weird - 8D audio (HUH?!?).
Despite the marketing departments going a little over the edge, binaural audio is incredibly fascinating technology and opens up a world of opportunities for music and sound.
The problem is when you first approach mixing 360 audio, it can be intimidating. You'll quickly realize that there is so much more space than you normally have when mixing in stereo and you can easily have a very thin sounding track at the end of it.
Despite massive advances in technology, many VR projects often end up using stereo music tracks because they think it sounds better.
However, that isn't the case! Properly mixed 360 audio can sound incredible In this article, I'm going to run through some important pointers about mixing 360 audio which you can apply to music and sound design. I'll be covering...
1) Horizontal vs. Vertical placement
2) Instruments and how it dictates placement choices.
3) Places in the 360 sphere to avoid.
Let's get to it!
Horizontal vs. Vertical Placement
In general, binaural technology is very good at horizontal placement. Much better than vertical. This means that you can pretty much use the entire horizontal area in front of the listener and they will easily be able to place it.
Vertical placement is a little more tricky. Listeners can easily place a sound that is at the 45 degree angle above them. If you go past that they will have problems placing it without any visual guidance.
Instrumentation
Listeners tend to like having low-pitched instruments at eye level. Having a low sound, such as a cello, high above them just doesn't make much sense and will quickly take them out of the immersive experience. So instruments such as cello, bass, viola and anything in the lower register should be kept on the horizontal plane.
On the other hand, high-pitched instruments can be above us. This tends to sit better with listeners as we can more easily place higher frequencies. So instruments such as flute, bells and violin can be above.
Instruments with a large range such as pianos, harps or synths, you have options. You can pan them up and down depending on what they are playing or
Areas to Avoid
Probably the most common mistake when mixing 3d audio is thinking that the entire sphere around the listener must be used at all times. This is not only false but heavily discouraged.
First area to be wary of is behind the listener. This area is best used for reverb or doubling instruments during a point in the song where it needs to be really big sounding. Putting an isolated melody or instrument behind the listener will likely confuse and disorient them.
Second area to avoid is directly above the listener - this is also called the Voice of God for those familiar with mixing high-density speaker systems. This is incredibly hard to place from a listener perspective and it will not sound good at all. This area is okay for movement - such as similuating a helicopter going overhead - but sounds should not be placed there permenently.
And that's a great place to start when mixing binaural audio! Hopefully this has given you a good starting place to start making the most of the latest and greatest technology and give you VR/AR projects an even greater level of immersion.
To Recap:
1) You can place musical elements pretty much anywhere on the horizontal spectrum in front of the listener and they'll be able to locate it.
2) Low pitched sound should be on the horizonal plane. Higher-pitched sounds you have more vertical options when since humans can more easily place higher frequencies .
3) Avoid putting anything in isolation behind the listener and directly above them.
Happy mixing!