Audibility thresholds for SINAD/THD measurements from auditory masking curves and hard clipped signal harmonics (pure-tone & two-tone).
Can we measure all nonlinear effects with one signal and apply the concept of worst-case analysis to multitone measurements?
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. Online simulation of sampling, demonstration of aliasing, oversampling.
12-bit, 14-bit and 16-bit noise floor comparison.
Does high-resolution audio sound better than CD? 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.
Extended version of Speaker Directivity Modeler with room response calculation from radiated sound power and free-field response (direct sound).
Online simulation of a speaker with a flat, completely rigid diaphragm mounted in an infinite baffle.
Simulation of early reflections from the floor, ceiling and from the wall behind the speaker. Baffle step and speaker directivity are also simulated.
Prediction of the audibility of noise in audio systems with "flat" noise floor from SNR.
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.
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.
How does high output impedance affect the sound of headphones; some notes on the damping factor; output impedance and nonlinear distortion.
Main topics: Calculation of the minimum cross-section. Shielded and twisted speaker cables. Speaker wire plugs. Table with recommended cable length. Calculation of the inductance loss.
Brief tutorial about audio interconnect cables.
Guitar amplifiers & speakers
Pre & post distortion filter measurements of a classic digital amp modeler.
Popular misconceptions about tube guitar amplifiers and tube distortion.
Measurements for the crazy ones.