First-order Tunable Dispersion Filter Demonstration

These are sample files to demonstrate the extended tunable dispersion filter proposed by Rauhala and Välimäki [1] based on the tunable dispersion filter design method [2]. All samples are in PCM WAV 44.1 kHz 16-bit format. The piano model includes the dispersion filter [1], a multi-ripple loss filter [3], a tuning filter, and an excitation model [4]. The piano model is calibrated using recorded piano samples [5].

Each sample has four piano tones: first a harmonic tone, then inharmonic tones with M values 1, 5, and 10, respectively. These samples correspond to Figure 5 in [1].

Samples:

Key 4 (C1, f0 = 32.7 Hz) (1.71 MB)

Key 16 (C2, f0 = 65.4 Hz) (1.71 MB)

Key 28 (C3, f0 = 130.8 Hz) (1.71 MB)

Matlab code:

Here is a Matlab script, which calculates the filter coefficient based on the f0, B, and M.

get_tdf_coeff.m

References

[1] J. Rauhala and V. Välimäki, "Dispersion Modeling in Waveguide Piano Synthesis Using Tunable Allpass filters," accepted for publication in Proc. 9th Int. Conference on Digital audio Effects, Montreal, Canada, Sept. 18-20, 2006.
[2] J. Rauhala and V. Välimäki, "Tunable Dispersion Filter for Piano Synthesis," IEEE Signal Processing Letters, vol. 13, no. 5, 2006, pp. 253-256.
[3] J. Rauhala, H.-M. Lehtonen, and V. Välimäki, ”Multi-ripple loss filter for waveguide piano synthesis,” in Proc. International Computer Music Conference, Barcelona, Spain, pp. 729-732, September 2005.
[4] J. Rauhala and V. Välimäki, "Parametric excitation model for waveguide piano synthesis," in Proc. 2006 IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP 2006), Toulouse, France, May 14-19, 2006.
[5] Original piano sample from University of Iowa Electronic Music Studios, theremin.music.uiowa.edu.

More information

Homepage of Jukka Rauhala
Piano research at the Acoustics Lab

http://www.acoustics.hut.fi/demos/ext-disp/
Modified: 14.6.2006