Troubleshooting: Audio distortion and playback quality issues

Crackles, dropouts, distortion, clicks between cues, or a general "something's wrong with the sound", almost always traceable to a few common causes. Work through them in order.

1. Buffer too low

The buffer size is how many audio samples KTPlayer hands to your audio device at a time. Smaller buffers mean lower latency, but also more work for the CPU. If the CPU can't keep up, you get crackles and dropouts.

  1. Open Preferences → Devices (⌘, ).
  2. Find the Buffer size dropdown. The default is 64 .
  3. Step up to 128 , 256 , or 512 . Higher numbers = more headroom, slightly more latency.
  4. Close Preferences and test playback.

For most shows, 256  is a safe sweet spot. Latency at 256 samples / 48 kHz is about 5 ms, imperceptible.

Buffer size in plain terms

The buffer is a small holding area where KTPlayer queues up audio for the interface to play. A bigger buffer = more breathing room for the CPU; a smaller buffer = faster response. For live triggering, the difference between 64 and 256 samples is inaudible, so go bigger if anything crackles.

2. Master or channel levels clipping

If any channel or the master is pushed above 0 dBFS, you may hear distortion or clipping.

  1. In the mixer, watch the channel meters during the cue that distorts.
  2. Any meter showing red (above 0 dBFS) is clipping. The peak value display below the fader is the red flag, it stays at the highest peak until you click it to reset.
  3. Pull the offending channel fader down until peaks stay below 0 dBFS.
  4. If the master is clipping, pull the master fader down or reduce the level of all faders.

3. Sample rate mismatch

KTPlayer runs at 48 kHz. If your audio interface is locked to a different sample rate elsewhere, macOS will resample on the fly, which sounds wrong and can introduce artifacts.

  1. Open Audio MIDI Setup (Applications → Utilities → "Audio MIDI Setup").
  2. Find your audio interface in the device list.
  3. Confirm the device's sample rate is set to 48000.0 Hz.
  4. If not, set it. Restart KTPlayer.

This is also the fix for "audio is out of tune". See Troubleshooting: Audio output is out of tune (sample rate issue).

4. Reduce CPU load

Unreliable audio playback can be caused by the Mac not having enough available CPU for real-time audio. To reduce the load:

  1. Quit every other app.
  2. Use a dedicated macOS user for performance. Create a separate user account that runs nothing but KTPlayer/ Log into it for shows so a cluttered everyday account can't interfere.
  3. Stop background sync and indexing. Pause any cloud sync (Dropbox, iCloud Drive, OneDrive, Google Drive, and Time Machine).
  4. Silence interruptions. Turn on a Focus / Do Not Disturb mode so notifications and disable automatic updates.
  5. Fix the power settings. If running on a laptop, connect to power and set the Mac never to sleep, and turn off screen savers.
  6. Check what's actually using the CPU. Open Activity Monitor (Applications → Utilities), sort by % CPU, and quit anything unexpected sitting high.

Still distorted?

  1. Try the show on a different audio interface.
  2. Try the show on a different Mac.
  3. Contact KeyboardTEK (support@keyboardtek.com) with the show file name, your macOS version, your audio interface, the buffer size you're running, and a description of when the distortion happens (specific cue? all cues? only at certain levels?).

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