Week 6 - Class One

This week we are starting a two week-long investigation of creating interesting audio soundscapes for artistic installations. As we've discussed, I'm often disappointed by the lack of interesting sound work done for art in general, and installation pieces are often the worst: unchanging drones that chase you out of a room faster than a blathering art critic.

One of the things we will want to do with our sound designs is prepare them for installation in a gallery or exhibit space. For example, we may be hired to put a sonic signature in a gallery during another artist's presentation, or we may wish to create a space of our own as a site-specific sonic artwork.

In any case, one of the things we will want to do is avoid overt repetition. Repetition is something that our brains are trained to spot; our brains want to eliminate any sound that is unnecessary for our survival, and repetitive sounds are generally useless.

In our sound design, repetition comes from looping all of our content too quickly.

There are two ways to avoid this:

We are, of course, going to focus on the second technique - because it is easier! The way that we will do this is to create items (either in the timeline or just using the standard audio editor) that have specific durations that we know are not going to repeat for a long time. But we are also going to use the session view to "test drive" these audio files to make sure that they sound good together.

In order to pick durations that are useful, we will need to focus on the individual track lengths (in seconds), and pick timings that aren't multiples of each other. For instance, if one track is 10 seconds long, and a second track is 20 seconds long, the first track will loop twice during the playback of the second, and the whole things will have a 20 second duration.

Not good!

If, on the other hand, we take on track that is 13 seconds, and a second track that is 55 seconds, the point at which repetition is heard is at 13 x 55 second, or 715 seconds (almost 12 minutes). Make each track longer - but not multiples - and you will get some really long repeat times. With one track at 180 seconds and another at 211 seconds, we get a repeat time of almost 11 hours. And this is just two tracks!

In most cases, we are going to focus on creating systems that use four tracks. Each track should be a length of > 1 minute (or our ear will start noticing the repetition too quickly), and each should be a unique duration. Once you get four tracks put together, you can lay them in an Audition Session, set each one to loop, then stretch them out over a long time.

Listen to the result, and look for the following:

In Class Assignment:


Week 6 - Class Two

Installation Videos:

In this second class for Week 6, we are going to pick up a few details to make our sessions more interesting. Why sessions, when we just spent the first half of the week using only the audio file editor? Because, once you understand how stems work, you will probably want to do a lot of stem creation using the Session system (and then exporting the mixdown as a single audio file).

Working with the Final Effects Stage

When we look at the mixer for a session, we can see that it has slots for effects - just like the sub channels did (where we inserted reverbs and delays). You can do a lot of things here, and they will affect all of the audio that runs through the system. So if you wanted to apply a reverb to everything, you could do it here.

However, reverb isn't the best thing to put here. Rather, we are going to focus on one of the key elements of final stage procession: compression and limiting. Compression is a way to take highly variant audio, and make it all sound about the same volume. We get into compression a lot more in Sonic Arts 2, but for now - if you want - you can play around with the many compressors available within Audition. In our case, we are going to focus on a limiter.

The limiter we will be using is the "Hard Limiter", found in the Amplitude and Compression segment of Audition's menu system.

The Hard Limiter has a few important controls that we will need to set. Here is a typical setting for me:

In this case, the controls are set for the following:

- Maximum volume will be -2 dB (just below full volume).
- I'm going to boost everything by 6 db (just to make everything seem a little louder).
- The look-ahead time and release time are irrelevant for most uses, so they can be ignored.

Why would we want to boost our sound, then make sure it isn't too loud? This pushes everything up, then chops off the top, leaving everything with a 'compressed' dynamic range. This is important in making the sound of your production LOUD without distorting on lesser reproduction systems.

From this point forward, you will probably always want to put a limiter on the master bus of any project that you mix; it will save you a lot of overloaded hassle, and prevent ear blow-out as well!

Inline Effects

One thing we never talked about was using effects on a single track in the session. This is easily done if you switch to the FX view of the session channels:

When you do this, a set of 'slots' are revealed for each track - slots that can contain effects. As an example, we can drop an echo effect on one of our tracks and not have to worry about setting up send busses or anything else. When you need to adjust the parameters, you double-click on the slot and you will see the effects window appear.

Remember this technique: it is a quick way to add an effect to a single track without having to destructively apply it to the audio file itself.

Modulation Effects

Two important effects that we haven't played with are found in the "Modulation" section of the effects system. They are the "Phasor" and the "Flanger". Both effects feature a swirling soundscape which can add animation to a static-sounding drone. But each uses a different technique to do it - and each has a unique sound.

Of the two, the phasor is more subtle. Here are the parameters of the phasor:

You can mostly use the presets, but you will often need to tweak the sound to suit your ears. Using the Depth will determing the depth of the 'swirls', the Feedback will determine the heaviness of the phasing. Finally, the Mix control will determine how much of the swirl is heard. Tweaking these three setting will often help you get it sounding right (if you've picked a useful preset).

The Flanger is a different beast, built off of modulating delay lines. It can be much more pronounced, and sounds much more like an effect rather than an environmental sound. Here are the parameters for the Flanger:

A somewhat different set of parameters, but the tweaking concepts are the same. Modulation Rate and Mix are the two key parameters, although Feedback can really make a difference as well. You'll need to test these effects to come to your own conclusions, but using the presets as a starting point is a good bet.

In Class Assignment: