/ Examples / Effects / MixGainPan

MixGainPan

In most cases a simple chain comprised of sound generator and Channel is sufficient to deliver your ideas to ears. There are times when a more complex audio signal chain is required and in those cases these plumbing nodes can be helpful.

In this contorted example, we explore notions of mono and stereo audio processing.

Channel Node

The Channel node is the heart of the audio processing piping. It has several features:

• The single input parameter can receive multiple inputs. These are automatically mixed. Incoming mono signals are converted to stereo.
  The Pan parameter allows you to place the mono signal at a point in the stereo field.
• The separate left and right inputs can also receive multiple signals.
• The of stereo output is broken out into left and right channels.
• There's support for an internal effects chain so you can keep your graphs tidy. Just alt-double-click to enter (and exit) the subgraph where you can introduce effects and filter nodes.
• The output can be chained with other channels to centralize control over effects and levels.
• Output can automatically be routed to the output for auditioning via its ToDAC parameter.

As we'll see, the capabilities of the other audio piping nodes are a subset of Channel's capabilities. In some cases, you may find that a more nuanced subset of Channel's capability may more clearly express your intent.

Gain Node

The Gain node is used to add/combine N signals into one while scaling the result. Remember than many UGens support a gain control so you needn't instantiate one simply to scale a single signal. Signals are combined according to its Op parameter. The usual operation is to add inputs (aka Mix) but its other options can come in handy:

• Add
• Difference (between first and subsequent)
• Multiply
• Divide (first by subsequent)
• Disable (produce 0 on output)
• Passthrough (produce inputs on output)

Pan Node

The Pan node used to convert a mono signal to stereo and to locate a signal in the stereo field.

Mix Node

The Mix node is used to mix stereo input down to a mono channel.

The Example

Here are the highlights of the graph seen below:

• SoundBuf output is modulated by combining it with the output of Modulate by selecting multiply in the Gain node's Op parameter.
• Panner is a CCGenerator that outputs a pulse-train of [-1, 1, 1, -1] representing the Pan parameter for Channel. This means that it places the signal at each stereo extreme (left, right) every 2 seconds.
• Channel turns around and breaks out the newly produced stereo signal into its left and right mono signals.
• ChanLeft and ChanRight captures the left and right channels for independent processing or auditioning.
• Mix2 takes two signals and combines them into a mono output.
• ChanMushed captures the mono input signal and applies effects to it.

You can trace the signals through the Channel nodes by invidivually toggles their ToDAC parameter. Initially, you can hear the final results because ChanMooshed has ToDAC checked. If you uncheck this parameter then enable ToDAC for Channel you can hear the effect of Panner. Next you can disable Channel's ToDAC and audition both ChanLeft and ChanRight signals.

Additional Examples

Two additional examples, testA.chg and testB.chg are provided to help you further explore your options for stereo effects configurations. The Two tests differ in one important way and we'll leave it as an exercise for you to hear the difference.