Digital audio

Noise perception, detection threshold & dynamic range

January 17, 2023 - What is the dynamic range of an audio system in which low-level signal transmission is affected by noise? Why is SNR not suitable for measuring the dynamic range of audio systems? Dispelling the misconceptions about SNR, dynamic range and noise perception... - The article also contains a comparison of noise audibility threshold of popular audio formats (16/44k, vinyl, reel-to-reel tape).

Listening test: Quantization noise & bit-depth 🔊 🎧

December 20, 2021 - Fortunately, investigation of bit-depth and quantization doesn't require complicated and tiring ABX tests and only takes a few minutes.

High-resolution audio vs. 16 bit / 44.1kHz

November 2, 2021 - Does high-resolution audio sound better than CD? Investigation of the optimal sampling frequency and bit depth of distribution audio formats.

Dynamic range of MP3 and AAC encoding

August 9, 2018 - Measurements of a fixed-point decoder and a floating-point decoder. 16-bit & 24-bit tests.


Loudspeakers & cables

Speaker cable guide

May 14, 2019 - 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.

Audio interconnect cables explained

February 28, 2019 - Brief tutorial about audio interconnect cables.

Frequency response of a speaker cabinet on the rear axis

April 25, 2018 - 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 speaker cabinet walls

November 25, 2017 - Measuring the sound radiation of different types of woods used in speaker cabinets. The effect of cabinet damping material on the sound radiation.

How to remove internal standing waves from speaker cabinets?

November 21, 2016 - The placement of sound absorbing materials is critical to achieve maximum sound absorption in speaker cabinets.


Headphones

Headphones & amplifiers - output impedance, load impedance and frequency response

October 20, 2020 - How does high output impedance affect the sound of headphones; some notes on the damping factor; output impedance and nonlinear distortion.


Guitar amplifiers & speakers

Roland Micro Cube (v1) Classic Stack model analysis & measurements

November 27, 2018 - Pre & post distortion filter measurements of a classic digital amp modeler.

Tube versus solid state: The truth behind tube distortion

November 9, 2018 - Popular misconceptions about tube guitar amplifiers and tube distortion.

Celestion Seventy 80 guitar speaker measurements

February 26, 2019 - Measurements.


Software downloads

Room Boundary Simulator (Windows)

August 21, 2019 - Simulation of early reflections from the floor, ceiling and from the wall behind the speaker. Baffle size (baffle step) and speaker directivity are simulated as well.

Rear wall reflection simulator (Excel)

August 23, 2019 - Rear wall reflection simulator with speaker cabinet (baffle step) simulation. Some extra notes on baffle diffraction.

Sound waves between two walls (Excel)

August 12, 2019 - Simulation of a sound source between two parallel walls. Frequency response, CSD (waterfall), impulse response.

Speaker directivity simulator and polar chart display (Excel)

September 9, 2019 - There are plenty of tools to display directivity: polar diagram (polar chart), DI (directivity index) vs. frequency, sound power vs. frequency, sonogram, parametric frequency response graphs...