1. No category

Computationally Efficient Hammond Organ
Synthesis
14th International Conference on Digital Audio Effects (DAFx-11), Paris, France
Jussi Pekonen, Tapani Pihlajamäki, and Vesa Välimäki
(Poster presentation by Julian Parker)
Department of Signal Processing and Acoustics
Aalto University School of Electical Engineering
Espoo, Finland
September 20, 2011
Objective
Create a digital model of the famous Hammond organ
Image source:
http://www.cameratim.com/reviews/
audio/hammond-123j3-organ/images/
hammond-123j3-organ.jpeg
Properties
Tone wheel synthesizer
Timbre control via drawbars
Leslie cabinet (rotating
speaker units), important
part of the sound!
Computationally Efficient Hammond Organ Synthesis
Pekonen, Pihlajamäki, & Välimäki (Parker)
SPA @ Aalto ELEC
2/4
September 20, 2011
DAFx-11, Paris, France
Implementation
Organ Model
Additive synthesizer (a few components)
Components that are not heard not generated
⇒ Computational savings
f0
0.5
×
1.5
1
2
3
5
4
6
8
×
×
×
×
×
×
×
×
+
+
+
+
+
+
+
+
“Key click” effect:
Emulated with
the sixth harmonic
Computationally Efficient Hammond Organ Synthesis
Pekonen, Pihlajamäki, & Välimäki (Parker)
SPA @ Aalto ELEC
3/4
September 20, 2011
DAFx-11, Paris, France
Implementation
Leslie Cabinet Model
Frequency and amplitude
modulation
Modulator 1
Input
HPF
SDF1
AM1
LPF
SDF2
AM2
+
Output
Modulator 2
Frequency modulation
with short spectral
delay filters (SDFs)
LIVE DEMO!
Computationally Efficient Hammond Organ Synthesis
Pekonen, Pihlajamäki, & Välimäki (Parker)
SPA @ Aalto ELEC
4/4
September 20, 2011
DAFx-11, Paris, France