Making Music
  Computer Music Software and Hardware

Standards in delay

These are the standard controls and parameters you'll find on a modern hardware or software delay or echo unit:

	Delay time This is simply the time between the delays or echoes. There may or may not be a lower limit. Very low values will produce an effect more like reverb than echo.
	Feedback This controls the amount of delayed signal that is fed back into the delay loop. With no feedback there will only be one echo. As you turn it up the number of echoes increases and with some effects extreme settings will cause the unit to feed back on itself and go into oscillation.
	Decay Not all effects have this but if they do it determines how quickly the echoes die away.
	Mix/Balance This governs the mix between the original sound and the processed sound.

Natural echoes repeat at regular intervals, decrease in volume as they die away and, as with all sounds that bounce off surfaces, the higher frequencies die away first. So to create a natural-sounding echo, that's how you need to set up your echo unit.

Tippety tap

Although natural echoes have regular repeats and die away in a uniform manner, there's no reason why a processed delay should work the same way. The multi-tap delay unit, therefore, offers several echoes or taps and gives the user control over each tap. So, for example, you may be able to specify separate delay times, feedback levels and volume settings for each echo.

Delay and echo are more commonly used with instrument tracks than vocals but although the modern preference is generally to use reverb on vocals, try echo for a different, slightly retro effect.

Sync and pan

One interesting feature of most modern software plug-in delay effects is their ability to synchronise the echoes to the tempo of the host sequencer. This is opens up a range of rhythmic possibilities which would be either very difficult or impossible to create outside of software.

Some delay units have a pan control which lets you pan the echoes to different parts of the stereo image. This can create some very interesting and striking effects and, again, would be difficult to do outside of software.

Reverb and echo are essential effects for the modern studio but, as with all effects, they need to be used with care, and not simply to try to beef up an otherwise average recording.

For more info... Delay - does a duck's quack echo? www.acoustics.salford.ac.uk/acoustics_world/duck/duck.htm Reverb - diagrams, technical stuff and maths: http://hyperphysics.phy-astr.gsu.edu/hbase/acoustic/reverb.html