Audio inputs and USB audio

The CrossPad has two audio codecs. Between them they carry three stereo inputs, the speaker output and the headphone output. The Mixer is where you hear and route all of them; USB audio sends a stereo stream to a computer and plays the computer’s sound with the pads.

Three inputs on two converters

Input	What it is	Mixer channel
Mic	the built-in microphones	IN1
Line 1/2	line input 1/2	IN2
Line 3/4	line input 3/4	IN3

The two codecs have one input converter each, so two of the three inputs are live at a time. The Mixer’s input pair picks which: Mic + 1/2 (the default), Mic + 3/4 or 1/2 + 3/4. The input left out of the pair is dimmed and reads silence; its gain and sends are kept for when you pick it again.

Gain is set per input, from 0 to +48 dB in 3 dB steps. The first +24 dB is analogue gain in the codec, the rest is digital. The defaults are +24 dB for the microphones and 0 dB for the line inputs. The Mixer, the Recorder and USB audio all hear the same gain, and the CrossPad keeps it across restarts.

Hearing an input

MONITOR on an input channel sends it to the outputs: Out 1/2 (the speakers), Out 3/4 (the headphones), both or neither. A microphone sent to the speakers next to it feeds back, as on any desk: monitor the microphones on headphones.

What a computer records

In MIDI + Audio mode the CrossPad is a USB sound card. Settings → USB → Recording Source picks what the computer records:

• Microphones, Line in, or Mix (mics + line), which sums both into one stereo stream.
• Sampler: the pads as the Mixer plays them, taken digitally. What the computer plays back never comes back into the take.
• Speaker bus and Headphone bus: the output buses.

The computer’s own sound comes in as the Mixer’s USB channel and plays together with the pads. The stream is stereo, at the engine’s rate, and the pads, the sequencer and the inputs keep playing while the USB mode changes.

When your DAW monitors the CrossPad’s input, record with Sampler, Microphones, Line in or Mix. The bus choices hand the DAW its own playback back, and the loop feeds back.

Mixer presets

The Mixer keeps six desks on the SD card, in crosspad/mixer/: every channel’s level, mute, solo, pan and sends, the output levels and the input gains. The first three start as STREAM, BEATS and SAMPLING, starting points for what they are named after; saving over one replaces it. LOAD keeps the desk it replaced, so UNDO brings it back. The USB rec level belongs to Settings and is not part of a preset.

For app authors

The inputs are reachable through crosspad-core’s PlatformServices: inputGain (IInputGain) and inputPairs (IInputPairs). inputPairs is null on a board without the choice of pairs, such as the PC simulator; check it before use.