8D music is an extremely fun experience for listeners that enjoy the excitement of moving sounds.
If you search a song with the keyword “8d audio”, you will find this song playing with the injected techniques of sound movement, which is quite different from the usual way you experience listening to music – it’s a “love it or hate it” kind of thing.
If you want to create your own 8D audio, it’s achievable with the right tools (some of them are free!), but the fun part is to be attentive as you make your audio location believable and fun to listen to. Everyone can move a sound from left to right, but it takes skill to make this movement interesting.
Some technicalities first
The spatialization of sounds is heard better in headphones, because when we listen on speakers, crosstalk will creep in and blur the localization cues.
Sound in real life reaches each ear once, which is very logical since there is one source of sound. This is not the case with speakers. When using speakers, we will hear both of them in both ears, thus making sound localization quite hard to translate for our ears (and brain).
Some of us might be happy to know that there is an interesting technology that can optimize crosstalk cancellation for audio over two loudspeakers – it’s called BACCH™ Filters. Using it means that your brain will be able to pick up on localization cues even on loudspeakers. But his is beyond the scope of this article.
Here’s a short video that demonstrate BACCH™ Filters:
Front – Back – Above – Below planes
While messing with localization of sounds consider the fact that it’s harder to distinguish between sounds from behind or in front, and it’s more complex to simulate sounds that come from below or above. In real life, we can get a better assumption if we change the position of our head while listening, in doing so we give our brain some differences to compare and get insights.
8D Audio skills – How can you make it fun and believable
Use better tools
Sound spatialization is achieved through numerous cues: phase, frequencies, level and time difference. There are many tools that use different techniques, I will mention some of them later in this article.
Not all tools are built the same. Choosing the right tool will make it easier for you to work on your 8D audio and will make it more believable that the sound really comes from different places in the room.
Tip: make sure you get some feedback from other people, each of us have a unique outer ear structure (Pinna) and can perceive your sound localization attempts differently. If there is a tool that gets more positive feedbacks, go with this one.
Synced & out of sync
One way to make 8D audio more interesting is to sync it with the tempo, beat or rhythm of the music.
For example, with an EDM track, you can let the kick help you make decisions of where the sound should travel to, for example 2 kicks on the left and 2 kicks on the right. You can also choose that every bar will move to a different random location, this will make your listeners more attentive because there will be no obvious structure.
Different musical styles will give you opportunities to create different movements. Try orchestral music, it will be a very powerful experience, also try Psytrance, Trap, Chillout, Ambience…
Synced sound movement is only one side of the coin, experiment with out of sync localization in some areas of the music – does it enhance your 8D experience?
Dry & added reverb
Some of the 8D audio you will hear on Youtube will present a known song with added reverb. Reverb is usually used in mixing to achieve the size of the space we are hearing the sound in, and a cue about the localization of the sound within that space, some reverbs can create the impression of the material the walls are built from.
But there is a downside to reverbs too… they blur the original audio and in some cases reverb will also mess with the rhythmic beauty of the song.
Tips for using reverbs in 8D audio:
- Convolution reverbs do a pretty good job at conveying the feel of a real space. They are usually CPU hungry. If you choose to go with digital reverb, make sure you can hear the depth disappear when you turn it off or bypass, good digital reverbs add spaciousness while bad ones just wash the original sound with more sounds.
- Moving sound inside a specific space will alter the reverb behavior too, for example, the further away the sound, the higher the proportion of the reverb will be. If the sound is closer and the space is bigger, the proportion of the reverb to original sound would be smaller and the pre-delay parameter will have higher values, since the original sound will reach our ears much faster than the wall reflections.
- An impressive use of the reverb is to add it to the opposite side of the original sound, this will create a big 3D space inside your headphones and a fun illusion for your brain. You can also make it dynamic by moving the reverb when the original sound is moving.
- To make sure the reverb doesn’t ruin the rhythm, or better yet, to make sure the reverb compliments the rhythm, you can adjust the length of the reverb and the pre-delay while listening to a rhythmic section of the song and check if the reverb is a positive addition.
- In some reverbs you can activate only the early reflections if you don’t want to soak your music with unnecessary reflections.
Free binaural VST plugins to create 8D tracks – anaglyph, ambeo and ambisonic
There are great free tools for binaural processing, they will make sure to implement the techniques needed in order to make your ears and brain believe sounds are coming from specific locations in space.
- Anaglyph – http://anaglyph.dalembert.upmc.fr/
- Ambisonic – another tool to control sound spatialization, it is meant for surround sound mixing, but with Ambidecoder you will be able to translate the changes in sound into headphones. Ambidecoder can be found in Cubase.
Here is a quick video about how to set it up:
The psychoacoustics behind sound spatialization in simple words
For the next techniques to work, there should be no crosstalk between the left and right channel, which means that the left channel will be panned all the way to the left and the right channel will be panned all the way to the right.
Setting a small delay (between 0.1 – 0.8 ms) on one of the channels will create a strong illusion that the sound is pulled into the opposite direction. For example, if we set the left channel to play at a 0.7ms delay, we will get the impression that the sound is coming from the right side.
Our head will block some frequencies from reaching our ears if a sound comes from one side. Filtering high frequencies will push the sound source to the opposite side.
If you use a low pass filter on both L & R channels you will push the sound further into the back.
Sounds that come from the right side will have a higher level in the right ear than sounds that come from the left side.
Distant sounds have less dynamic range and the transients are less prominent. You can use a compressor with fast attack and high ratio to create this effect.
Comb-filtering of the outer ear (Pinna) – Sounds coming from above or below will have different comb filters applied to the original sounds, that’s due to the shapes of our outer ear – the Pinna. Some tools simulate these kinds of localization cues but since every ear is different, it’s somewhat less accurate than the other spatialization techniques discussed here.
There are special psychoacoustic effects like reversing the phase on one channel only, which will create the feeling that the sound is coming from all around you but doesn’t have a specific position. Beware though, playing this technique in mono will cancel the sound. If your music is meant for headphones only, just export a stereo version and you are good to go.
The next level…
The next level of 8D audio would be controlling every sound in the song and making it dance with the music, making some sounds extremely big while making others extremely small, moving different sounds in opposite directions … the options are endless with this setup.
Another step forward…
If you like the idea of 8D audio and have never stepped into the magnificent world of surround mixing, you are going to find it even more satisfying, simply because… there are actually more sound sources, which means more freedom for you to control the sound source position. In surround mixing you will have a palette of tools like Ambisonic and Dolby Atmos. Both are very interesting tools to control spatialization and how we are experiencing sound.