Category Archives: Digital Audio

A bit about reverb

Reverb is one of the most interesting aspects of digital signal processing effects for audio. It is a form of processing that is well-suited to digital processing, while being completely impractical with analog electronics. Because of this, digital signal processing … Continue reading →

Posted in Convolution, Digital Audio, Impulse Response, Reverb | 12 Comments

The Fourier series

(Java is no longer supported by many popular browsers, and can be difficult to enable others…) Experiment with harmonic (Fourier) synthesis with this Java applet! The sliders represent the levels of the first eight harmonics in the harmonic series. The second harmonic … Continue reading →

Posted in Digital Audio, FFT, Fourier, Widgets | 3 Comments

A question of phase

If you’ve paid attention for long enough, you’ve seen heated debate in online forums and letters to the editor in magazines. One side will claim that it has been proven that people can’t hear the effects of phase errors in … Continue reading →

Posted in Digital Audio, Phase | 5 Comments

The jitters

When samples are not output at their correct time relative to other samples, we have clocatz jitter and the associated distortion it causes. Fortunately, the current state of the art is very good for stable clocking, so this is not … Continue reading →

Posted in Digital Audio, Jitter | 2 Comments

What is aliasing?

It’s easiest to describe aliasing in terms of a visual sampling system we all know and love—movies. If you’ve ever watched a western and seen the wheel of a rolling wagon appear to be going backwards, you’ve witnessed aliasing. The … Continue reading →

Posted in Aliasing, Digital Audio | 16 Comments

What is dither?

To dither means to add noise to our audio signal. Yes, we add noise on purpose, and it is a good thing. How can adding noise be a good thing??!!! We add noise to make a trade. We trade a … Continue reading →

Posted in Digital Audio, Dither | 43 Comments

Oversampling

In this discussion, “oversampling” means oversampling on output—at the digital to analog conversion stage. There is also a technique for oversampling at the input (analog to digital) stage, but it is not nearly as interesting, and in fact is unrelated … Continue reading →

Posted in Aliasing, Digital Audio, Sample Rate Conversion | 4 Comments

Digital audio: theory and reality

The promise of perfect audio—the Nyquist Theorem Most people who’ve look at digital audio before know about the Nyquist theorem—if you sample an analog signal at a rate of at least twice its highest frequency component, you can convert it … Continue reading →

Posted in Aliasing, Digital Audio, Dither, Jitter, Phase | 12 Comments