Audio Stuttering or "Skipping" during Playback
If the audio cuts out for a second or "stutters," the Headphone Dust MKV file isn't being read fast enough.
- The Drive Speed: If playing from a USB stick, ensure it is a USB 3.0 drive or higher. Older USB 2.0 sticks are too
slow for 4K video + TrueHD audio.
- The Network: If streaming over a home network (Plex/NAS), ensure you are using a wired Ethernet connection. 5Ghz
Wi-Fi can work, but it is prone to interference that causes audio drops.
- Apple TV Specific Fix: In Apple TV Settings, go to Video and Audio > Audio Format. Ensure "Change Format" is set to
OFF. Setting this to "On" forces a re-encode that often causes skipping.
High-resolution multichannel audio (such as 5.1 FLAC at 24-bit/96kHz) is one of the most demanding formats for a home
cinema setup. Unlike standard movie soundtracks (Dolby Digital or DTS), which are compressed, these FLAC files are
typically decoded into uncompressed LPCM before being sent over HDMI.
This guide explains why stuttering occurs across different devices and how to stabilise your playback.
1. The Core Issue: The "HDMI Clock"
When you play high-resolution audio, you are pushing a massive amount of data through a "pipe" that requires perfect
timing.
- Clock Drift: The Player and the Receiver must stay perfectly synchronised. If the player’s internal clock is
slightly faster or slower than the Receiver's, the audio buffer will eventually empty or overflow, causing a
"stutter" every few seconds or minutes.
- Bandwidth: 24-bit/96kHz 5.1 audio requires significantly more bandwidth than a standard 4K movie soundtrack. Any
weakness in the HDMI chain will manifest as audio dropouts.
2. Hardware Fixes (Physical Layer)
Before changing software settings, ensure the "pipe" is clear.
- Upgrade to HDMI 2.1 "Ultra High Speed" Cables: Even if you aren't watching 8K video, these cables have much better
shielding and tighter tolerances for the "Audio Return Channel" and clock signals.
- Simplify the Chain: Connect the player directly to the Receiver, not the TV. Passing high-res multichannel audio
through a TV via eARC is a frequent cause of sync errors and stuttering.
- Disable HDMI CEC: This is the most common "hidden" fix. CEC sends small data pulses between devices to control power
and volume. These pulses can interfere with the high-precision clock required for 96kHz LPCM. Turn off "HDMI
Control" or "CEC".
3. Software & Player Settings
If the hardware is solid, the issue is likely how the player handles the file.
A. Sampling Rate Management
- The "Lock" Method: Many players have a setting called "Sampling Rate Switch" or "Match Native Sample Rate." While
this sounds good (it preserves the 96kHz), it forces the Receiver to "re-handshake" every time a song starts.
- The Fix: If you get stutters, try disabling this and forcing a fixed output of 48kHz or 192kHz. Most AVRs are much
more stable when the frequency doesn't change.
- Downsampling: If the stuttering persists at 96kHz, set the player to limit output to 48kHz. While technically a loss
in resolution, it is often the only way to achieve 100% stable multichannel playback on certain chipsets.
B. Audio Output Mode
- HDMI RAW vs. LPCM:
- For FLAC, the player must decode it to LPCM because receivers don't "speak" FLAC natively.
- However, if you are playing DTS-HD or TrueHD and getting stutters, ensure the player is set to RAW/Bitstream. This
offloads the heavy processing work to the receiver, which has dedicated chips designed for this task.
C. Network Buffering (SMB vs. NFS)
If you are streaming these files from a NAS or PC:
- Switch to NFS: If you are using SMB (Windows Sharing), try switching to NFS. NFS has lower overhead and is generally
more stable for high-bitrate media playback on Linux-based players like Zidoo and Dune.
1. Increase Buffer Size: In apps like Kodi or specialised media players, look for "Cache" or "Network Buffer" settings
and increase them to "Large" or "Max."
Pro Tip: Check the "Audio Delay" or "Auto Lip Sync" settings on your audio receiver. Sometimes the Receiver's attempt to
sync video with high-res audio causes the processor to "hiccup." Try turning "Auto Lip Sync" OFF to see if the audio
stabilises.
