Author Archives: Nigel Redmon

Envelope generators—ADSR Part 2

Posted on June 2, 2013 by Nigel Redmon

Certain aspects of the ADSR are up for interpretation. Exactly how the ADSR re-triggers when not starting from idle, for instance. Also, we can decide whether we want constant rate, or constant time control of the segments. The attack segment … Continue reading →

Posted in Envelope Generators, Synthesizers | 17 Comments

Envelope generators—ADSR Part 1

Posted on June 1, 2013 by Nigel Redmon

After discussing the exponential decay of the one-pole filter in a recent article, I couldn’t help but think about envelope generators. Besides, it would be handy to have one to test out some of these other components I’ve been writing … Continue reading →

Posted in Envelope Generators, IIR Filters, Synthesizers | 1 Comment

Wavetable oscillator video

Posted on May 27, 2013 by Nigel Redmon

If you find this video helpful, let me know, and I’ll work more video demonstrations into articles.

Posted in Aliasing, Synthesizers, Video, Wavetable Oscillators | 6 Comments

About synthesizer control voltages

Posted on April 14, 2013 by Nigel Redmon

Since I write about simulating classic analog synthesizers (a process often called “virtual analog”), mostly notably in my wavetable oscillator series so far, I wanted to touch on the topic of parameter control signals. Classic synthesizers have knobs to set … Continue reading →

Posted in Synthesizers | 1 Comment

Perspective on dither

Posted on March 24, 2013 by Nigel Redmon

Recently, I’ve had lengthy discussions on the topic of dither with a couple of different people—of opposite views. One believes that everything should be dithered, including truncations to 24-bit. The other feels that dither is a waste of time even … Continue reading →

Posted in Dither | 4 Comments

Replicating wavetables

Posted on March 3, 2013 by Nigel Redmon

My WaveTableOsc object uses a series of wavetables that are copies of single-cycle waveforms pre-rendered at a progressively smaller bandwidth. By “replicating wavetables” I mean taking a full-bandwidth single cycle waveform, and using it to make a complete set of … Continue reading →

Posted in Oscillators, Source Code, Wavetable Oscillators | 53 Comments

About source code examples

Posted on March 3, 2013 by Nigel Redmon

My goal is to teach audio DSP principles in a way that is more intuitive than most available material. And part of that goal is to help you to think about the your goals and how to solve them by … Continue reading →

Posted in Source Code | 2 Comments

Ventilator adapter in a mint tin

Posted on February 16, 2013 by Nigel Redmon

I don’t eat mints often, but when I do, they are sugar free… A Leslie speaker simulation Players of Hammond organs and their clones know how important the Leslie speaker is to the classic sound. Modern clones have electronic simulations … Continue reading →

Posted in Uncategorized | Leave a comment

A one-pole filter

Posted on December 15, 2012 by Nigel Redmon

Here’s a very simple workhorse of DSP applications—the one-pole filter. By comparison, biquads implement two zeros and two poles. You can see that our one-pole simply discards the zeros (the feed-forward delay paths) and the second pole (feedback path): We … Continue reading →

Posted in DC Blocker, Digital Audio, IIR Filters, Source Code | 40 Comments

A note about de-normalization

Posted on December 3, 2012 by Nigel Redmon

One ugly thing that we need to be aware of, especially for filters, is the de-normalization of numbers. Basically, computer processors try to keep floating point numbers normalized—they try to keep them in the binary form 1.xxxxxx (where each x … Continue reading →

Posted in Digital Audio | 1 Comment