Total distortion measurement with a sine signal is the simplest and most popular non-linear distortion measurement method. Although not the best measurement (considering hearing of distortion components), hard clipped signal harmonics and auditory masking curves can provide reliable audibility thresholds.

A multitone measurement that combines the sensitivity of sine signal measurement with the all-revealing nature of multitone measurements.

This interactive tool calculates "audibility curves" from SNR and peak SPL using a simple human hearing model. The noise in the modeled system has a flat spectrum (similar to white noise).

What is the dynamic range of an audio system in which low-level signal transmission is affected by noise? - Dispelling the misconceptions about SNR, dynamic range and noise perception...

Sampling theory made simple. Demonstration of sampling, aliasing, oversampling.

By listening to the residual noise at different bit-depths, we can easily answer the question "how many bits are needed".

High-resolution audio: even better than the real thing? Investigation of the optimal sampling frequency and bit depth of distribution audio formats.

Measurements of a fixed-point decoder and a floating-point decoder. 16-bit & 24-bit tests.

Two popular "dirt-cheap" headphones from the past. The "borderline" category of headphones.

How does output impedance affect the frequency response? Some notes on damping factor.

It seems that above 5 kHz directivity index (DI) and frequency response ("room response") doesn't tell the whole story... "In-ear" analysis of different radiation patterns, focusing on the contribution of side reflections to the diffuse-field response.

Approximation of the frequency response of a speaker cabinet on the rear axis with a first-order low-pass filter. With this method, the reflection from the wall behind the speaker can be calculated simply and with sufficient accuracy.

Measuring the sound radiation of different types of woods used in speaker cabinets. The effect of cabinet damping material on sound radiation.

The placement of sound absorbing materials is critical to achieve maximum sound absorption in speaker cabinets.

Simulation of early reflections from the floor, ceiling and from the wall behind the speaker. Baffle step and speaker directivity are also simulated.

Excel workbooks for studying speaker directivity. Polar chart, frequency response vs. angle, sonogram (color map).

Simulation of a sound source between two parallel walls. Frequency response, CSD (waterfall), impulse response.

Measurements for the crazy ones.