Effects are a means of altering the quality of the sound we have recorded. In soundtrack design, we tend to be aiming to replicate an environment. We have recorded a pure, direct sound, and need to make it sound as ‘real’ as possible.
Any sound can be described in terms of Frequency and amplitude. Frequency can be used to talk about how much bass or treble is in the sound. We can also talk about frequency spread; ie the width of the sound between the lowest and highest frequencies heard. Amplitude refers to the height of the sound wave, and can be seen as an indicator of volume.
Effects
There are 4 basic types of effect:-
- Equalization
- Time Based (Phase, Flange, Chorus, Echo, Delay)
- Distortion
- Dynamics (Compression / Limiter)
Equalization refers to those effects that alter the frequencies of the sound. In general terms, it is better to record a wide frequency spread, and cut the sounds that you don’t want – it is easier to remove what is there than to add what isn’t. This includes Graphic and Parametric EQ, and High and low pass filters.
Time based effects are those that add a delay to the signal and mix it back in with the original. Phaser and Flanger modulate the second signal to put it out of phase – this gives a kind of wobble to the sound. Lengthen that delay, and it becomes Chorus and begins to sound like there is now more than 1 sound source. Reverb consists of lots of very close delays which decay (how long the echoes last for) over time. Echo and delay kind of do what they say on the tin – the delay time is long enough that it is heard as a separate sound.
Distortion is when the recording of the sound has clipped. This distorts the sound from the original. In general terms, you tend to want to avoid this is sound design, but can be useful to warm sounds up.
Dynamic range is the difference between to quietest and loudest parts of the sound. Compression will reduce this overall, while a limiter will effect it over a certain volume. Expanders will increase the dynamic range. A noise gate will only open when the volume is above a certain threshold. This can be useful for hiding background noise – you could set the threshold to the volume of the speech in a recording, and it will remain closed when there is only background noise, and open for the speech. The speech, as it is closer to the mic, will mask the background noise.
You should now have added Foley and Dialogue to your video file. Play with these effects, getting used to how they work. Everything you do in Soundtrack is non destructive (you can undo it), so you can pretty much do what you like. The aim is to add effects that make it sound real, and quite often less is more!
o What are the different effects?
o When are they used?
o Why are they used?
o How are they done?
o What skills are needed?
o What equipment is needed?
o What are the strengths?
o What are the weaknesses?
o How can you use these in your design?
o How successful was your practical task?
o How has your design changed?
Alan Hardcastle
minodef
Tao of Teaching 