Center channel Impedance.

[StevenSurprenant]

E-Stat and StevenSurprenant,

I found the formula for how much acoustic power (db) changes with added source that have the same volume. It is rather interesting.

Formulas: Δ L = 10 × log n where
Δ L = level difference; n = number of equal loud sound sources.

If we have two sources of the same volume, the loudness acoustic gain is 3 db. But if we have three sources of same volume, the acoustic gain is only 4.8 db. And if we have four, the acoustic gain is 6.0. Here is table:

(Number of n equal loud sound sources) = (Level increase Δ L in dB)

1 0 = 0 db
2 = 3.0 db
3 = 4.8 db
4 = 6.0 db
5 = 7.0 db
6 = 7.8 db
7 = 8.5 db
8 = 9.0 db
9 = 9.5 db
10 = 10.0 db
12 = 10.8 db
16 = 12.0 db
20 = 13.0 db

As you can see, as we add more sources of equal volume, the changes in acoustic power changes less and less

That's good to know and very interesting. Thank you!