Examples - Master audio PA Serie Manual Usuario

Example 1
The B6/T MASTER AUDIO cabinet includes an impedance switch from 150Ω (52W)
to 800Ω (12W).
We have, then, two basic data: the maximum power of each box (Watts) and the
impedance (Ohms). We can calculate the maximum number of boxes per channel
starting from these data.
a) Starting from the power (Watts). If we select 52W(150Ω), we would be able to
connect up to 3 boxes in parallel (per channel).
b) Starting from the impedance (Ohms). If we select 150Ω and we divide by 64
(minimum impedance of the amplifier/channel):
If we choose 800Ω(12W) we will be able to connect up to 12 boxes.
You can overload the amplifier with more cabinets in case of "medium-low" power
working. The 100V are only reached at the peaks of the musical program.
Example 2
If you want to know the power of a cabinet or a 5KΩ horn, you should use Ohm's
Law:
We have 100V at maximum power; square it and you get 10000; divide it by the
impedance (Ohms) of the cabinet/horn (5000) and you will get 2 Watts on each
device. This means that you are able to connect up to 75 boxes in parallel (150W
total power).
All these calculations may be done on PA-600TL, knowing that there, the power is
300+300 W at 32Ω. This means that the amplifier admit the double number of units
connected.
52W x 3 boxes = 156 Watts
150Ω / 64Ω = 2,3 boxes (3 boxes/channel)
2
V
W =
Ω
12