Title
Efficient antialiasing oscillator algorithms using low-order fractional delay filters
Abstract
One of the challenges in virtual analog synthesis is avoiding aliasing when generating classic waveforms such as sawtooth and square wave which have theoretically infinite bandwidth in their ideal forms. The human auditory system renders a certain amount of aliasing inaudible, which allows room for finding cost-effective algorithms. This paper suggests efficient algorithms to reduce the aliasing using low-order fractional delay filters in the framework of bandlimited impulse train (BLIT) synthesis. Examining Lagrange, B-spline interpolators and allpass fractional delay filters, optimized methods will be discussed for generating classic waveforms (sawtooth, square, and triangle). Techniques for generating more complicated harmonics such as pulse width modulation, hard-sync, and super-saw are also presented. The perceptual evaluation is performed by comparing the threshold of hearing and masking curve of oscillators with their aliasing levels. The result shows that the BLIT using the computationally efficient thirdorder B-spline generates waveforms that are perceptually free of aliasing within practically used fundamental frequencies.
Year
DOI
Venue
2010
10.1109/TASL.2009.2035039
IEEE Transactions on Audio, Speech & Language Processing
Keywords
Field
DocType
low-order fractional delay filters,square wave,computationally efficient thirdorder,efficient antialiasing oscillator,low-order fractional delay filter,b-spline interpolators,virtual analog synthesis,efficient algorithm,allpass fractional delay filter,aliasing inaudible,aliasing level,computationally efficient third-order,classic waveform,blit,oscillators,sawtooth,spline,fundamental frequency,interpolation,pulse width modulation,propagation delay,bandwidth,music,cost effectiveness,spline interpolation,audio signal processing,oscillations
Bandlimiting,Propagation delay,Computer science,Pulse-width modulation,Algorithm,Speech recognition,Aliasing,Bandwidth (signal processing),Harmonics,All-pass filter,Sawtooth wave
Journal
Volume
Issue
ISSN
18
4
1558-7916
Citations 
PageRank 
References 
7
0.60
11
Authors
4
Name
Order
Citations
PageRank
Juhan Nam126125.12
Vesa Välimäki2474100.64
Jonathan S. Abel324425.08
Julius O. Smith4720155.42