Audio guides
Fourteen guides on why speakers, headphones and microphones go wrong, what the numbers on the box actually mean, and what you can do about it. Each one goes hand in hand with one of the tools.
Bluetooth Audio Latency by Codec
How much delay each Bluetooth codec really adds, and why the numbers you'll find online don't agree.
Hearing Range by Age
How the top of your hearing changes decade by decade, and why 20 kHz was only ever a young person's limit.
Dead, Blown or Miswired: Diagnosing a Silent Speaker
How to tell a dead speaker, a blown one and a wiring fault apart, with no special equipment.
Why Is One Earbud Quieter Than the Other?
A blocked mesh, a nudged balance setting or a failing speaker, checked in the order that finds the cause fastest.
Out of Phase: What Reversed Polarity Sounds Like
Why a missing stereo centre usually means swapped wires, and why you can't hear it from one speaker alone.
Why Isn't My Microphone Working?
The four things a microphone has to get past, with the settings for Windows, macOS, Linux, Discord, Zoom and Meet.
How Loud Is Too Loud? Safe Listening Limits
What the WHO recommends for everyday listening, what workplace limits say, and why they don't match.
Sample Rate and Bit Depth Explained
What 44.1 kHz and 24-bit really mean, why digital audio isn't a staircase, and where 44.1 kHz came from.
Stereo, Mono and Surround: Channel Layouts Explained
What 2.0, 5.1, 7.1 and Atmos mean, why the ".1" isn't a full channel, and why channel order varies.
White, Pink and Brown Noise: What the Colours Mean
What makes each noise colour sound different, and why pink noise is the one used for measuring.
Headphone Impedance and Why It Matters
Why 32 Ω and 250 Ω headphones sound different on the same device, and when a headphone amp really helps.
Total Harmonic Distortion (THD) Explained
What a distortion figure really tells you, why it's meaningless on its own, and why you can't compare brands with it.
Speaker Placement and Room Acoustics Basics
Why your room shapes your bass, where to put your speakers, and why corners make bass boom.
How to Test Your Phone's Earpiece Speaker
Why no website can test the speaker you hold to your ear, and the checks that work with the phone itself.
Want to check your screen too? The Dead Pixel Test guides cover stuck pixels, backlight bleed and burn-in.