HOW2inAE – Audio Spectrum

HOW2 use the Audio Spectrum effect in Adobe After Effects to generate patterns that react to the melody, not just the volume.

Here is a type of pattern that can be produced.

This tutorial is long overdue. Problems with YouTube blocking the music I first used for copyright, and a project to make long form videos as background video walls for music performances, delayed its completion. For those uniterested in the arcania of AE FX editing, here is a gratuitous Trump gif….

The tutorial demonstrates how to use the AE Audio Spectrum effect to react to the melody and produce a star-ring type pattern.


HOW2inAE- Audio Spectrum

Having been distracted by constructing long videos as video wall or back projection visuals for music in clubs and bars this tutorial is long overdue. In this tutorial I hope to show how to deal with the AE audio spectrum effect.

This is the sort of effect that this can produce.

Because YouTube kept objecting to the music I wanted to use I have gone back to a previous video I made to some Bach. 
This is something I worked on in 2008 or possibly before, note this video is size Hi-Rez at the time
This is just to provide an audio file for the audio spectrum effect, the video will not be used.

So let’s make a composition of the right length and Add that video for the audio file source 
then add a black solid and in the effects add an audio spectrum waveform, which of course is in generate, not audio.

As a default it comes in as a line across the centre. For this effect it needs to be moved to the top a few hundred pixels down. 
Select the layer with the audio to be used in the top selection box.
To capture the melody the lower frequency needs to be above a frequency of 200 to avoid too much bass. 240 is used here. That is just below middle C on a piano.
The main melody will rarely cover more than three octaves so an upper frequency of 1.2 K should work. This narrow range should focus on the main melody and avoid too much of the bass, higher harmonics or percussion.

We want a lot of frequency bands more than 100, 120 is used here and the maximum height needs to be the maximum 32,000 appears to be the limit.

To correctly analyse the lower notes requires that the software has enough time so  240 ms is sampled. To compensate the audio offset is set to the negative value of the sample length.

Thickness is adjusted until the lines fill in the spaces.
Juggling with the colour wheel and the line colours can give a variety of effects.

The position of the audio spectrum line is adjusted so that only the loudest cross the top of the frame.
The next step is to add a number of Fx to this audio spectrum. 
First is the Mosaic. Adjust the size of the Mosaic to break up the regularity of the digital lines. Then add from the stylise effects the find edges, invert it and mix it back to get outlines on the coloured bars.

Further control over the colour can be had by adding a Colorama effect. Note that by using alpha as the driving value, A wider range of colours may be available.

the next effect is the polar coordinates from the distort menu.
Change the type of correction to rectangular to polar, and turn the effect up to hundred percent to get a ring with radiant bars.
The diameter of the Ring can be adjusted by adjusting the level of the audio spectrum line and the colour range and intensity of the bars can be adjusted by altering the find edges and Colorama ratios.

Adjusting the relative values to get the colour outline and appearance that is desired can be endless and will be speeded up to save the sanity of all involved.

The next effect added is the cc light rays. This should be placed in the centre with quite a large radius and very little warp softness, it can then be turned up in intensity until it generates light rays along the louder note bars.

Finally Glow and cc radial fast blur are added and adjusted to taste. 
This will again be time shifted to avoid tedium. 
With many variables in play many different appearances are possible while a particular look resulted in this case during adjustment it may well be that other usable looks or styles will appear.

So with a lot of adjustment and the addition of a masked processed noise that is modified by the audio translated to keyframes and with an expression applied to the noise evolution the final version can be rendered.

(Spoiler alert! bonus effect after credits.)

Here’s another short sample of another effect possible with the audio spectrum waveform.

Here is some of the video wall technology now finding its way into entertainment venues for which I am seeking to provide content.

As before I want to acknowledge the many people that make tutorial videos from which I have derived much inspiration. And the motivation to make my own. Here are a few.



One response to “HOW2inAE – Audio Spectrum

  1. Fascinating. Thanks for posting.

    I am currently tied up in external ventures, and have had little (read zero) time for blogging for some time. Will send you an e-mail when I get a chance.


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