
Recent Posts
 Sampling theory, the best explanation you’ve ever heard—Part 3
 Sampling theory, the best explanation you’ve ever heard—Part 2
 Sampling theory, the best explanation you’ve ever heard—Part 1
 Sampling theory, the best explanation you’ve ever heard—Prologue
 Amp simulation oversampling
 Guitar amp simulation
 About coefficient conventions
 Filter frequency response grapher
Archives
 August 2017
 May 2017
 January 2017
 December 2016
 September 2016
 February 2016
 September 2015
 January 2015
 March 2014
 January 2014
 October 2013
 June 2013
 May 2013
 April 2013
 March 2013
 February 2013
 December 2012
 November 2012
 May 2012
 March 2012
 January 2011
 December 2010
 November 2010
 July 2007
 March 2003
 February 2003
 August 2002
 January 1997
 November 1996
 October 1996
 August 1996
 July 1996
Categories
 Digital Audio (54)
 Aliasing (9)
 Convolution (3)
 Dither (7)
 Filters (23)
 DC Blocker (1)
 FIR Filters (7)
 IIR Filters (17)
 Biquads (11)
 Fourier (3)
 FFT (3)
 Impulse Response (5)
 Jitter (2)
 Oscillators (8)
 Phase (2)
 Reverb (2)
 Sample Rate Conversion (10)
 Sampling Theory (5)
 Effects (1)
 Envelope Generators (5)
 MIDI (2)
 Source Code (7)
 Synthesizers (9)
 Uncategorized (5)
 Video (4)
 Widgets (12)
 Digital Audio (54)
Category Archives: Aliasing
Guitar amp simulation
In this article, I’ll sketch a basic guitar amp simulator. For one, questions on the topic come up often, and also, it will be a good example of a typical use of working at a higher sample rate. The most … Continue reading
Posted in Aliasing, Digital Audio, Sample Rate Conversion
3 Comments
Wavetable oscillator video
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
A wavetable oscillator—Part 2
From Part 1, we have an oscillator. But we need to broaden it to allow scaling of harmonic content based on pitch so that we have all the harmonic content we need at the low frequency end, and, as we … Continue reading
Posted in Aliasing, Digital Audio, Oscillators, Wavetable Oscillators
14 Comments
Sample rate conversion: down
In doubling the sample rate, we inserted zeros between existing samples, then used a lowpass filter to remove the resulting alias in the audio band. To resample at half the current rate, we use a lowpass filter to remove audio … Continue reading
Posted in Aliasing, Digital Audio, Filters, Sample Rate Conversion
Leave a comment
Sample rate conversion: up
Once we have a suitable set of FIR filter coefficients from our windowed sinc calculator, it’s time to apply them. Again, our recipe for doubling the sample rate: 1) Insert a zero between existing samples. (This is the upsampling step, … Continue reading
Posted in Aliasing, Convolution, Digital Audio, Filters, FIR Filters, Sample Rate Conversion
7 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
15 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