Why does emulator audio crackle when the frame rate drops by just 2 or 3 FPS?

Emulators generate audio samples synchronized with video frames. At 60 FPS, a frame is delivered every 16.6ms. If the processor lags and delivers a frame at 22ms, the hardware digital-to-analog audio buffer runs out of samples (buffer underrun), resulting in an audible buzzing or crackling pop.

How does Dynamic Rate Control stop audio stutter in RetroArch?

Dynamic Rate Control subtly adjusts the emulated audio resampling pitch by up to 1-2% in real-time, speeding up or slowing down audio to match your handheld screen's exact refresh rate without any audible pitch distortion or clicks.

🔊 Sound Engineering & DSP Telemetry

Audio Latency & Sound Crackle Fix Guide

Why buffer underruns cause ugly speaker buzz when games drop frames, how AAudio and ALSA eliminate button-to-sound lag, and the exact Dynamic Rate Control settings to fix stutter forever.

⚡ DSP Latency Engine

Audio Buffer & Latency Tuning Calculator

Calculate total button-to-speaker response delay and find the sweet spot between zero crackle and instant audio response.

1. Audio Driver API

2. Audio Buffer Size (ms)

3. Dynamic Rate Control (Audio Sync)

Total Audio Delay46 ms

Frame Latency Equivalent2.7 Frames

Crackle ResistanceHigh

Perceptual RatingNear-Instant

💡

AAudio combined with a 32ms buffer delivers a crisp 46ms total response time (under 3 frames of audio lag). With Dynamic Rate Control active, minor frame dips will never cause sound crackling.

Handheld Audio API Benchmarks

Tested hardware response latency and driver CPU overhead across Android and Linux.

Audio API Driver	Hardware Latency	Target Operating System	CPU Overhead	Verdict
AAudio (Android 8.1+)	12ms - 18ms	Android (RP5, Odin 2, RG406H)	Ultra Low	Best modern choice for Android handhelds. Provides near-instant sound response on button presses.
OpenSL ES (Android)	35ms - 50ms	Android (Legacy & Android 11)	Low	Reliable fallback if AAudio experiences device-specific driver clicks on older Unisoc builds.
ALSA Direct (Linux CFW)	6ms - 12ms	Linux (muOS, Knulli, ArkOS)	Minimal	The gold standard for low latency. Direct kernel hardware access with zero desktop sound server lag.
TinyALSA (Linux)	10ms - 15ms	Miyoo Mini (OnionOS) / TrimUI	Microscopic	Designed for low-RAM embedded handhelds. Extremely light CPU footprint.
AudioTrack (Java Legacy)	95ms - 150ms	Android Fallback	Medium	Avoid! Massive perceptible lag between pressing the jump button and hearing the sound effect.

Switch to AAudio or ALSA

In RetroArch on Android: Open Settings → Driver → Audio Driver and switch from opensles to aaudio. Cuts button-to-sound lag by over 50%.

Enable Dynamic Rate Control

In RetroArch: Settings → Audio → Synchronization → Dynamic Rate Control: ON. Sets maximum rate control delta to 0.005 to silently resample audio during minor frame pacing hitches.

NetherSX2 SPU2 Async Mix

In NetherSX2 (PS2): Set Audio Settings → Synchronization Mode to Async Mix instead of Timestretch. Eliminates the high-pitched robot buzzing when heavy PS2 games drop below 60 FPS.