Reference Manual

CHAPTER 13. ROUTING AND I/O 183
placing each one in a Rack's device chain.
Note that the main outputs of the multi-timbral instrument will still output to the track that
contains the instrument - only auxiliary outputs are available to the External Instrument
device.
Feeding Sidechain Inputs
Some effects have so-called sidechain inputs. A vocoder, for instance, imposes spectral
characteristics taken from one signal (say, spoken word) onto another signal, for instance a
string pad. The vocoder is inserted as an audio effect into the string track. It has a sidechain
input for the speech signal, which has to be delivered from another track. So, we create an
additional audio track named Speech and set its Output Type chooser to the Strings
track. From the Output Channel chooser, we select the vocoder's sidechain input.
Routing a Speech Signal
Into a Vocoder's
Sidechain Input.
Some vocoder plug-ins include a built-in synthesizer to generate the carrier signal. In
this case, the only difference from the above procedure is that the vocoder instrument is
dragged into a MIDI track. Feeding the side-chain audio input works as described above.
Please note that Ableton's
Auto Filter, Compressor, Gate and Vocoder devices have their
own sidechain controls with integrated routing choosers that match those found in tracks.
Thus when using these devices, it is not necessary to follow the above procedure - you can
simply select the sidechain source from within the device itself.