$ minidsp input --help
minidsp-input
Control settings regarding input channels

USAGE:
    minidsp input <input-index> <SUBCOMMAND>

ARGS:
    <input-index>    Index of the input channel, starting at 0

SUBCOMMANDS:
    gain       Set the input gain for this channel
    help       Prints this message or the help of the given subcommand(s)
    mute       Set the master mute status
    peq        Control the parametric equalizer
    routing    Controls signal routing from this input

gain / mute

# Sets input channel 0's gain to -10dB
minidsp input 0 gain -- -10

# Mute input channel 0
minidsp input 0 mute on

routing

Each output matrix entry has to be enabled in order for audio to be routed. The gain can then be set (in dB) for each entry.

# Route input channel 0 to output channel 0, boost gain by 6dB
minidsp input 0 routing 0 enable on
minidsp input 0 routing 0 gain 6

peq

$ minidsp input 0 peq --help
minidsp-input-peq
Control the parametric equalizer

USAGE:
    minidsp input <input-index> peq <index> <SUBCOMMAND>

ARGS:
    <index>    Parametric EQ index (all | <id>) (0 to 9 inclusively)

FLAGS:
    -h, --help       Prints help information
    -V, --version    Prints version information

SUBCOMMANDS:
    bypass    Sets the bypass toggle
    clear     Sets all coefficients back to their default values and un-bypass them
    help      Prints this message or the help of the given subcommand(s)
    import    Imports the coefficients from the given file
    set       Set coefficients

The peq commands supports broadcasting an operation on multiple peqs. If specifying an index, the command will only affect a single filter.

Bypass the first peq: minidsp input 0 peq 0 bypass on

Bypass all peqs: minidsp input 0 peq all bypass on

Importing filters should use the all target if the unused filter should also be cleared. minidsp input 0 peq all import ./file.txt

$ minidsp output --help

Control settings regarding output channels

USAGE:
    minidsp output <output-index> <SUBCOMMAND>

ARGS:
    <output-index>    Index of the output channel, starting at 0

SUBCOMMANDS:
    compressor    Controls crossovers (2x 4 biquads)
    crossover     Controls crossovers (2x 4 biquads)
    delay         Set the delay associated to this channel
    fir           Controls the FIR filter
    gain          Set the input gain for this channel
    help          Prints this message or the help of the given subcommand(s)
    invert        Set phase inversion on this channel
    mute          Set the master mute status
    peq           Control the parametric equalizer

Gain

$ minidsp output 0 gain --help
USAGE:
    minidsp output <output-index> gain <value>

ARGS:
    <value>    Output gain in dB

Example usage: minidsp output 0 gain -- -20

-- is used to distinguish negative values from another option

PEQ

$ minidsp output 0 peq --help
Control the parametric equalizer

USAGE:
    minidsp output <output-index> peq <index> <SUBCOMMAND>

ARGS:
    <index>    Parametric EQ index (all | <id>) (0 to 9 inclusively)

SUBCOMMANDS:
    bypass    Sets the bypass toggle
    clear     Sets all coefficients back to their default values and un-bypass them
    help      Prints this message or the help of the given subcommand(s)
    import    Imports the coefficients from the given file
    set       Set coefficients

The peq commands supports broadcasting an operation on multiple peqs. If specifying an index, the command will only affect a single filter.

Bypass the first peq: minidsp output 0 peq 0 bypass on

Bypass all peqs: minidsp output 0 peq all bypass on

Importing filters should use the all target if the unused filter should also be cleared. minidsp output 0 peq all import ./file.txt

Crossover

$ minidsp output 0 crossover --help
Controls crossovers (2x 4 biquads)

USAGE:
    minidsp output <output-index> crossover <group> <index> <SUBCOMMAND>

ARGS:
    <group>    Group index (0 or 1)
    <index>    Filter index (all | 0 | 1 | 3)

SUBCOMMANDS:
    bypass    Sets the bypass toggle
    clear     Sets all coefficients back to their default values and un-bypass them
    help      Prints this message or the help of the given subcommand(s)
    import    Imports the coefficients from the given file
    set       Set coefficients

Crossovers are implemented as series biquad filters. There are two groups of 4 biquads per channel. Each group can be bypassed individually.

The command follows the same syntax as the peq command, for the exception that you have to specify the group index.

They can be imported in REW's format:

minidsp output 0 crossover 0 all import ./file.txt
minidsp output 0 crossover 1 all import ./file2.txt

FIR

$ minidsp output 0 fir --help
minidsp-output-fir
Controls the FIR filter

USAGE:
    minidsp output <output-index> fir <SUBCOMMAND>

SUBCOMMANDS:
    bypass    Sets the bypass toggle
    clear     Sets all coefficients back to their default values and un-bypass them
    help      Prints this message or the help of the given subcommand(s)
    import    Imports the coefficients from the given file
    set       Set coefficients

Importing FIR filters can be done using a wav file. The file's sampling rate MUST match the device's internal rate.

minidsp output 0 fir import ./impulse.wav
minidsp output 0 fir bypass off

Delay

$ minidsp output 0 delay --help
minidsp-output-delay
Set the delay associated to this channel

USAGE:
    minidsp output <output-index> delay <delay>

ARGS:
    <delay>    Delay in milliseconds

Invert

USAGE:
    minidsp output <output-index> invert <value>

Example: minidsp output 0 invert on