Coupling and reciprocity

Introduction to electroacoustics - Electroacoustic transduction

Figure 2 - Reciprocal passive quadrupole representing two first-order circuits (Z1 and Z 2 ) coupled by an impedance Z c

Figure 3 - Determining the reciprocity factor of a quadrupole by measuring the ratio i 2 /u1

Figure 4 - Determining the reciprocity factor of a quadrupole by measuring the ratio

Figure 5 - Homogeneous coupling of two first-order mechanical circuits

Figure 6 - Notations used for determining the impedance brought back from a point of abscissa x2 to a point of abscissa x1

Figure 7 - Notations used to determine the internal radiation impedance of a membrane

Figure 8 - Phase shift between the force exerted on a first-order mechanical system and its vibratory velocity

Figure 9 - Determination of the mechanical impedance of a membrane loaded by a tube of length

Figure 10 - Graphical resolution of the natural frequency equation for a membrane loaded by a closed tube: cotan y &#61; Ay – (B /y )

Figure 11 - Equivalent mechanical diagram of a membrane loaded by a closed tube in the low-frequency approximation

Figure 12 - Graphical resolution of the eigenfrequency equation of a membrane loaded by an open tube :

Figure 13 - Equivalent mechanical diagram of a membrane loaded by an open tube in the low-frequency approximation

Figure 14 - Schematic diagram of a membrane charged by a tuned cavity

Figure 15 - Equivalent circuit diagrams of figure  in the low-frequency approximation

Figure 16 - Virtual impedance Z v of a tube of cross-section S 2 brought back to a cavity of cross-section S1

Figure 17 - Diagram obtained after reducing the impedance of the tube in figure  with cross-section S 2 to the end of the cavity with cross-section S1 (partial reduced impedance).

Figure 18 - Equivalent diagrams obtained after reducing the impedance of the tube with cross-section S 2 to the diaphragm (total reduced impedance).

Figure 19 - Schematic diagram showing the relative displacement of two air cylinders with radii r and r &#43; dr and thickness dr

Figure 20 - Air velocity profile in a capillary tube with a cross-section of

Figure 21 - Air flow velocity profile in a slot of width L and thickness h such that

Figure 22 - Schematic diagram of the porosity measurement bench for a sample of material used to dampen acoustic waves.

Figure 23 - Evolution of the directivity curve of a single-channel loudspeaker with frequency

Figure 24 - Notation used to calculate the pressure induced at a point  for an embedded flat circular piston

Figure 25 - Elemental pressure induced at point  by a surface element dS &#039;

Figure 26 - Elementary pressure induced at a point on the axis by the elementary surface :

Figure 27 - Curve showing reduced pressure as a function of distance r along the axis of an embedded flat disk

Figure 28 - Notation used to determine the pressure induced at a point  by an embedded flat disk.

Figure 29 - Pressure directivity function of an embedded flat disc

Figure 30 - Directivity diagram of an embedded flat piston corresponding to ka &#61; 10

Figure 31 - Variations in the Q directivity factor as a function of the parameter