  ## Cyril Touzé

### Sound synthesis of gongs and cymbals

Web Companion page for the paper :

#### Modal approach for nonlinear vibrations of damped impacted plates: Application to sound synthesis of gongs and cymbals,

##### by M. Ducceschi and C. Touzé, Journal of Sound and Vibration, vol. 344, 313-331, 2015. [Sciencedirect/JSV]

This web-page is the companion page of the paper published in the Journal of Sound and Vibration, vol. 344, 313-331, 2015. The sound files associated to the paper are here given. They are produced from the modal code developed for that purpose (see paper). The WAV files are obtained from the velocity of a single point of the plate. First, the WAV files corresponding to the paper are listed and given. Then, supplementary results, not commented in the paper, are also provided, in order to show the versatility of the method for producing accurate and realistic sounds.

#### Circular plate

##### Case of a large gong

The case of a circular plate with a free edge is considered. The diameter is 80 cm and thickness 1mm. The interaction time Twid is 6 ms.
• Case 1 : Input force 40 N, sampling rate Fs = 40 kHz, Nphi = 1000
• Case 2 : Input force 80 N, sampling rate Fs = 40 kHz, Nphi = 1000

These two cases corresponds to the Figure 4 of the paper reproduced below The same sounds can be obtained without alteration of quality, by using a smaller sampling rate Fs, and, for the first one, by using only 500 modes:
• Case 1bis : Input force 40 N, sampling rate Fs = 20 kHz, Nphi = 1000
• Case 2bis : Input force 80 N, sampling rate Fs = 20 kHz, Nphi = 1000
• Case 1ter : Input force 40 N, sampling rate Fs = 20 kHz, Nphi = 500

##### Case of a cymbal

The cymbal is first approximated with a circular plate of diameter 40 cm. The thickness is 0.5 mm. To mimic the hard impact of a drumstick, a short interaction time Twid is selected as 1 ms. This case corresponds to Fig. 5 in the paper.
• Input force 120 N, sampling rate Fs = 80 kHz, Nphi = 1000

#### Rectangular plate

##### Effect of damping

The influence of damping is demonstrated on a rectangular plate with simply supported boundary conditions and in-plane movable edges. The size of the plate is Lx=0.4m, Ly=0.6m, and thickness h=1.2 mm. The interaction time is selected as 7 ms, and the magnitude of input strike is 300 N. The damping is roughly speaking multiplied by ten between the two simulations. This case corresponds to Fig. 7 in the paper.
• small damping, sampling rate Fs = 50 kHz, Nphi = 500, Npsi=60
• large damping, sampling rate Fs = 25 kHz, Nphi = 250, Npsi=150
##### Fast simulation
The same plate with a soft strike is considered. Retaining a small number of modes in this case leads to a fast simulation (approx. 1 minute CPU per seconds of sounds), still a rich, pleasant and realistic sound is obtained. The WAV file corresponds to Fig. 8 of the paper. Interaction time Twid=8ms, magnitude of force pm=80 N.
• Soft strike, pm=80 N, Nphi=100, Npsi=150, Fs=40 kHz

#### A collection of various sounds

A collection of WAV files obtained during the testing of the codes are here provided in order to illustrate the rich palette one can obtain.
##### Circular plate
• cymbal-like, input force 150 N, Fs = 50 kHz
• cymbal-like, input force 100 N, thickness 0.8mm
• cymbal-like, force 200 N, large damping
• gong-like, diameter 1 m, pm=80 N, N=1000, Fs=20 kHz
• gong-like, diameter 80 cm, pm=250 N
• gong-like, Twid = 10 ms, pm=250 N
##### Rectangular plate
• linear sound with short interaction time
• linear sound, different timber
• cymbal-like
• another cymbal-like
• small gong, soft impact
• large gong
• large gong, very soft impact
• gong-like
• still another gong, pm = 100 N
• the same gong with pm = 300 N

Michele Ducceschi maintains a page on Soundcloud where other examples might be found.

Page created on monday september 8, 2014