Current Version

AudioBox was released open-source on April 16th, 2022.

AudioBoxBaby is an application that detects the tempo of music in real-time and outputs this information via MIDI to control music/VJ/digital art software.


A quick-start guide to running AudioBoxBaby:

  1. Choose your Audio Input Device from the drop-down
  2. Choose a sampling rate (44100 is fine)
  3. Click the Sample button
  4. Play some music on your computer and you should see the Left and Right volume level meters show the incoming signal (if not then refer to the trouble shooting guide below)


  • No audio input (“Left and “Right” volume monitors are a zero)
    • Make sure you are playing some music!
    • Open the sound control panel: Start -> Control Panel -> Sounds and Audio Devices
    • Click on the “Audio” tab
    • Under “Sound recording” click on “Volume”
    • On the “Recording Control” window, go to Options -> Properties
    • Choose the same “Mixer device” as you’ve selected in AudioBox Baby
    • Click on the “Recording” radio-button if it’s not already selected
    • Under “Show the following volume controls” make sure you have “Recording Control” and “Stereo Mix” selected
    • Click OK
    • Make sure the “Mute” box under “Stereo Mix” is not selected (i.e. doesn’t have a tick in it)
    • Make sure the “Mute all” box under “Recording” is not selected
  • AudioBox Baby doesn’t detect the tempo
    • While the tempo detection algorithm is quite sophisticated it won’t work on all types of music
    • Make sure the recording volume is set correctly – if the signal is too quiet then AudioBox Baby will have a harder time trying to figure out the tempo
    • Don’t use low sampling rates (minimum recommended is 22,050)
  • The beat counter isn’t in time with the music
    • The beat may be locked to an off-beat. Use the beat-shift buttons to correct this


Sample: Start sampling audio using the given audio device and sample rate (44100 is good)

Lock: Lock the current tempo

Tempo Tap: manually tap out the tempo

<<: Shift the current beat once to the left

1/2: Divide the current tempo by 2

x2: Multiply the current tempo by 2

>>: Shift the current beat once to the right

Status Bar

BPM: Currently detected tempo in beats per minute

TDC: Tempo Detection Confidence

TC: Tempo map Confidence (anything over 40% is good)

SC: Sync Confidence


  • MME/DirectSound/ASIO audio input
  • Sends a MIDI note-on message once per beat
  • Sends the current beat phase to a MIDI controller
  • Tempo lock
  • Manual tempo tapping
  • Beat shift left/right
  • Tempo double/half


As this is the free version of AudioBox there are some limitations:

  • No automatic input gain
  • Single tempo detection algorithm (a high-pass filter with simple beat-onset detection) – other versions of AudioBox will have multiple, simultaneous algorithms
  • Only one MIDI note and MIDI controller output based on the current tempo – other versions will have multiple outputs
  • Always outputs the current tempo regardless of confidence and input tonal state
  • No frequency/chord detection
  • No frequency band output
  • Lack of other ephemeral measurements

16 thoughts on “AudioBox”

  1. I ran a Kickstarter campaign to raise funds for an update to AudioBox but there wasn’t enough interest. I’m afraid I don’t have time to work on projects that won’t at least pay for themselves.

      1. Unfortunately, at the moment, it’s not a question of money, rather of time, of which I don’t have any.

        Stay tuned, however, as there will be some movement on this later in the year.

  2. Good evening,
    Ive just stumbled across this piece of softwear and its like a godsent as there literally doesnt seem to be a softwear based solution to this problem. Sadly it seems that the version provided on github doesnt seem to be capable of sending out a midi clock signal. Is the larger, more comprehensive version of this softwear still available or did I miss anything?
    Thank you in advance,
    Leonard Lehr.

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