User manual

QTA 1360P/1480P
User Manual
User Manual Q-Tech Commercial Series
QTA 1360P/1480P
8
Output Impedance Output Impedance Output Impedance
0.1W 100KΩ 10W 1KΩ 40W 250Ω
0.5W 20KΩ 15W 667Ω 50W 200Ω
1W 10KΩ 20W 500Ω 75W 133Ω
2W 5KΩ 25W 400Ω 100W 100Ω
3W 3.33KΩ 30W 333Ω 150W 66.7Ω
5W 2KΩ 35W 286Ω 200W 50Ω
(100V plan) P = E x E / Z = 100x100 / Z = 10,000 / Z
P: Power(W), Z : Impedance (Ω), E : 100V(Designed voltage of a general-use amplifier)
High impedance of speakers and output calculation table for 100Volt systems
For the benefit of those who want to calculate
the power of the system with a formula. See
below:
Determining power by calculating
total impedance
The alternative to counting the speaker taping
watts is to calculate the total impedance of
the line, which will also indicate the wattage
necessary to drive the system correctly.
The computational formula is voltage squared
divided by impedance:
Power = Voltage2 / Impedance
When the speaker line reaches its top voltage
of 70 Volts, the formula is:
Power = 5000 / Impedance (because 70
squared equals 5000).
To measure impedance a dedicated meter is
required. These use a 1k frequency to send an
alternating current through the transformer(s).
The resulting figure indicated by the meter’s
dial can be cross referenced with the meter’s
impedance chart to see what value should be
expected and the power that will be required.