Apple Logic Express 9 - Manual (Page 286)

Using Insert Effects
When a plug-in is inserted directly into a channel strip, it is termed an insert effect.
All of the signal is processed, or, put another way, 100 percent of the signal flows through
the effect. This behavior is suitable for equalizers or dynamic effects, such as compressors.
If you have enough processing capacity, you can use up to 15 insert effects on each
channel strip.
By default, only two Insert slots are shown on channel strips. An extra blank Insert slot is
automatically created as soon as all of the currently displayed Insert slots are used, up to
the maximum allowed. So if you insert an effect plug-in into Insert slot 2, a third slot is
shown automatically. If you insert a plug-in into slot 3, a fourth is shown, and so on.
For more information about routing effect plug-ins in a series, see Routing Audio in the
Mixer via Insert Effects .
Using Send Effects
When you use send effects, a controlled amount of the signal is sent to the effect. Sends
are typically used for effects that you want to apply to several signals at the same time.
286 Chapter 10 Working with Instruments and Effects