Theory
Anechoic: every port absorbs what reaches it, as for the transmission loss; the results describe the model alone. Outlets radiating: every outlet ends in the radiation impedance used for the insertion loss (the outlet's own termination, unflanged by default, radiating into the ambient air), and the inlets stay anechoic. The reflected waves are folded in exactly from the stored matrix. The equations are in Port results: noise reduction, reflection, absorption, impedance, transfer functions, four-pole.
With outlets radiating, only the inlets are offered for the reflection coefficient, impedance and absorption, and the transmission and dissipation coefficients are not shown: they are properties of the model and are given for anechoic ports. The four-pole is always for anechoic ports.
Equations
| where | meaning | unit |
|---|---|---|
| Stored scattering matrix | - | |
| Reflection matrix of the outlet terminations; zero when anechoic | - | |
| Waves sent in at the excited inlet(s) | Pa | |
| Waves arriving at and leaving the ports | Pa |
Default and rule
- Default
- Anechoic
- Rule
Anechoic.
Valid range anechoic | outlets radiating
Terminations
The radiation impedance is the plane-mode one; above the outlet's first non-plane cut-on the higher modes leave the outlet unreflected, unless the run computed a radiation domain.