In-Line Processing Using The Insert Jacks (Compressors & Equalizers) - Alesis Studio 12R Reference Manual

You don't need to connect anything to the other input of the effect,
because most effect units use the stereo inputs only to provide a
path for the "dry" stereo signal when the effect is connected directly
between an instrument and an amplifier. In mixing applications
such as with the Studio 12R, you will set the effect's wet/dry balance
all the way to "wet" (effects only, no direct signal). The effect device
will generate an artificial stereo output from the signal input.
Check the manual for your effect device for more information.
On the other hand, true dual-channel effects processors (such as the
Alesis QuadraVerb 2) may be connected to two different sends to
take advantage of the dual processing capability. Dual-channel
processors allow the left and right inputs to be used for different
kinds of effects (for example, the left input to a stereo chorus while
the right input is used for a stereo reverb).
Using Aux 1 as an effects send
Note that [AUX 1] may also be used as an extra effects send.
Although Aux 1 is a pre-fader send, and normally used for stage
monitoring or a separate headphone mix while recording, it may
also be used as an effects send so you can add different effects to
different channels. Just remember that the "PRE" under [AUX 1]
means that when you move a fader up or down you won't change
the level going to an effect from Aux 1. If you change fader levels,
you will need to adjust Aux 1 levels to maintain the same balance
between dry and effected signal.
In-line processing using the INSERT jacks
(compressors & equalizers)
Some signal processors are designed to be used on one signal at a time, with the entire
signal being processed instead of a mix of effected and uneffected signal. The purpose of
the INSERT jacks on channels 1-8 is to allow you to insert a compressor, equalizer, or
other effect into the signal path of a single channel after its preamplifier and [TRIM]
control, but before the Studio 12R's own EQ, aux sends, and fader. The INSERT jacks
may also be used as direct outputs to a recorder.
The INSERT connector is a TRS (tip/ring/sleeve) 1/4" jack which
consists of an insert send (the tip of the TRS plug) and an insert
return (the ring of a TRS plug). A special Y-cable consisting of a
TRS 1/4" plug on one end and two mono 1/4" plugs on the other
end is required.
Studio 12R Reference manual
Connections
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