Operation Manual

6.11 Bowed Membrane 76
the direction of the motion. The second input signal is a force signal which is considered to act
perpendicularly to the motion of the beam. Third input is a pitch modulation signal.
Typical Use. See Bowed Multimode module.
The default value of the following parameters is set during construction
• Length: the length, in meters, of the beam.
• Frequency: fundamental frequency, in Hertz, of the beam when there is no pitch modulation
signal or when its value is equal to 0. Note that the fundamental frequency is independent
of the length of the beam. The software automatically calculates the physical parameters
necessary to obtain the required fundamental frequency. The default value of this parameter
is 261.62 Hz which corresponds to the middle C (C3) of a piano keyboard. This setting is
convenient when controlling a Bowed Marimba module with a Keyboard module.
• Decay: proportional to the decay time of the sound produced by the beam.
• Number of Modes: number of modes used to simulate the object. As the number of modes
is increased, the number of partials in the sound increases but also inevitably the calculation
load.
• Excitation point: x-coordinate, in meters, of bow from the extremity of the beam.
• Listening point: x-coordinate, in meters, of listening point from the extremity of the beam.
To obtain proper functioning, the excitation and listening points should be the same.
Note: For more details on this module and especially the front panel controls, see the Bowed
Multimode module.
6.11 Bowed Membrane
The Bowed Membrane module simulates sound produced by bowed rectangular membranes of
different materials and sizes. This module first calculates the modal parameters corresponding
to membrane-shaped objects according to the value of the different parameters requested at con-
struction time and, next, calls the Bowed Multimode module to simulate sound production by the
membrane. The module has one output, the sound produced by the membrane, and three inputs.
The first input signal is the bow velocity in the direction of the motion. The second input signal is
a force signal which is considered to act perpendicularly to the motion of the membrane. The third
input is a pitch modulation.
Typical Use. See Bowed Multimode module.
The default value of the following parameters is set during construction
• length: the length, in meters, of the membrane.