Echo takes the selected portion of the sound and mixes it with the rest of the sound at the specified delay. Selecting Echo from the menu will bring up a dialog box with the following five parameters, Echo, Delay, Repeat, Filter, and Filter Type. The default parameters will give a fairly natural echo effect.
The Echo field can have a range of 0 to 100% It controls the amplitude of the echo. For example if the Echo is 50% and Repeat at 2 times, the first echo would be 50% as loud as the original sound, and the second echo would be 50% as loud as the first echo. At 100% the echo never fades away.
The Delay field can have a range of .0001 to 9.9999 seconds. It controls the amount of time between echoes.
The Repeat field can have a range of 0 to 100 times. It controls the total number of echoes. To make the echo to fade away naturally, set Repeat to 100 times, and as soon as the echo amplitude is zero, the processing is stopped so no time is wasted.
The Filter field can have a range of 0 to 100%. It controls how much filtering the echo gets.
The Filter Type popup menu has the choice of Low Pass and High Pass filters. The filters have a -12 db per octave slope. To simulate a cave, use little or no filtering. To simulate a room with sound absorbing things in it, try the Low Pass Filter at about 25%. To simulate the outdoors where low frequencies are less noticeable, try the High Pass Filter at about 25%.
The Presets popup menu has the choice of 9 different echo types.
Notes
For best results there should enough silence at the end of the sound so the echo can fade away naturally.
Echo is similar to Reverb, but it sounds a little cleaner, you can control the number of echoes, and it echoes past the selection. If you want to stay within the selection use Reverb instead.