Frequently Asked Questions (FAQ)
What is Audio Tester and how does it work?
Audio Tester is a hardware-grade, browser-based diagnostic utility designed to test channel balance, frequency response, stereo panning, speaker phase polarity, and driver distortion without downloading external software.
It utilizes the browser's native Web Audio API to synthesize high-precision audio nodes (sine waves, triangle waves, stereo panners, and gain nodes) for real-time acoustic signal generation directly inside your sound card memory.
Why can't I hear low sub-bass frequencies (below 30Hz)?
Inability to hear 20Hz–30Hz tones usually stems from physical transducer hardware limits or human hearing roll-off. Most standard headphones and small desktop speakers roll off sharply below 40Hz and cannot displace enough air pressure to produce low sub-bass.
Additionally, human hearing requires significantly higher decibel volume levels to perceive ultra-low frequencies compared to midrange frequencies.
How do I test if my audio is out-of-phase (inverted polarity)?
Use our Phase / Polarity Check module to toggle between In-Phase (Normal) and Out-of-Phase (Inverted) audio signals.
In-phase audio should sound full, solid, and focused directly in the center of your head or room. Out-of-phase audio will sound hollow, diffuse, lacking central presence, and completely stripped of low-end bass response due to wave cancellation.
What causes audio channel imbalance (one side quieter than the other)?
Left/Right channel imbalance is commonly caused by worn analog potentiometer volume knobs on headphone cables, asymmetrical ear seal/clamping force, dirty 3.5mm jack contacts, OS-level stereo pan miscalibration, or natural manufacturing driver mismatch tolerances.
Why is there a delay or lag in my Bluetooth audio during frequency sweeps?
Bluetooth audio introduces natural latency due to digital encoding, wireless packet transmission, and decoding buffers. Standard Bluetooth codecs like SBC or AAC carry 100ms–250ms of latency.
For low-latency diagnostic testing or competitive gaming, use a wired connection or low-latency codecs like 2.4GHz wireless dongles or aptX Low Latency.
Will running frequency sweeps or bass tests damage my headphones or speakers?
No, running pure sine or triangle wave frequency sweeps at reasonable listening levels is completely safe for audio drivers.
However, avoid cranking your system master volume to extreme levels during low-frequency (20Hz–50Hz) or high-frequency (15kHz+) tests, as over-excursion or thermal overload can stress voice coils.
What is frequency response and why is it important for audio gear?
Frequency response measures an audio device's amplitude output across the audible human hearing spectrum (20Hz to 20,000Hz).
An accurate frequency response ensures sound is reproduced as intended by mixing engineers, without overwhelming bass boom, muddy midrange frequencies, or harsh treble spikes.
Why do I hear static, crackling, or popping during audio tests?
Audio pops or crackling are typically software buffer underruns caused by high DPC latency, heavy CPU background usage, mismatched digital sample rates (e.g., 44.1kHz vs. 48kHz), or dirty physical jack connections.
Do I need an external DAC or amplifier to use this tool properly?
No, this tool works directly through any standard onboard sound card, USB headset, DAC/Amp setup, or Bluetooth device connected to your operating system.
What is the upper limit of human hearing and how high can I test?
Healthy young human ears can generally perceive frequencies up to 20,000Hz (20kHz). However, age-related hearing decline (presbycusis) and ambient sound exposure naturally lower this upper limit to between 12kHz and 16kHz for most adults.
Is my browser audio output recorded, logged, or saved?
No, all Web Audio API nodes generate waveforms in real time strictly within your browser's local client memory. No audio streams or personal diagnostic results are ever recorded, transmitted, or stored on external servers.
Which web browsers support full Web Audio API diagnostics?
All modern web browsers fully support real-time Web Audio API synthesis and panning controls, including Google Chrome, Mozilla Firefox, Microsoft Edge, Brave, and Apple Safari across Windows, macOS, Linux, Android, and iOS.