(1) L = 10Log {[RE (P into / p transparent)] 2 [IM (p into / p-through)] 2}
(2) RE (P into / p transparent) = 1 /
4M
(1 COS2KL2) {4MCOSK (L1-L2) (
3M
-1) Cosk (L1 L2) (M 1) Cosk (L1
-3L
2)
(3) IM (p into / p transparent) = 1 /
4M
(1 cos2kl2) {2 (M2 1) SINK (L1-L2) (
2M
2
-M 1) SINK (L1 L2) (M 1) SINK (L1
-3L
2)
P intramography in ------- Mensus sound pressure, P Transmission --------- Mensus Transmission Sound
M --------- Expansion ratio (M = muffler diameter cross-sectional area / insertion tube cross-sectional area)
L1 --------- Monorrier single room expansion room length (m); L2 -------- Insert tube length (m);
K = 2πf / c; f -------- muffle frequency (Her); c ---------- speed (m)
