Precision Power PCX1250 - Manual (Page 9)

The following is a basic formula to be used as a guide to determine current draw.
A50% amplifier efficiency rating is used as an average. Your new
P C X™ a m p l i f i e r
is more efficient than most other amplifiers. This formula is to be used as a guideline.
Using wire of a larger gauge can only improve the current transfer of your system.
Do not use smaller gauge wire.
Total RMS output x 2 = Total Input Wattage
Total Input Wattage = Current Draw (in Amps)
Supply Voltage
Example: A POWERCLASS™ PCX 1500 amplifier has two channels at 200w
per channel RMS rating into 4 Ohms (500 x 1 = 500).
You would use the formula in the following way:
500W x 1 = 500W
500W = 41.6 Amps Total current draw.
12V
If the same amplifier is driven into a 2 Ohm mono load, double it's 4 Ohm RMS
rating. All
POWERCLASS™ amplifiers will effectively double their power at this
load.
500W x 1 x 2 = 1000W
1000W = 83.3 Amps Total current draw.
12V
If you are using more than one amplifier, add up the total current draw for all of
them and choose the appropriate gauge based on the grand total.
NOTE: The ground wire should be the same gauge as the power wire.
Recommended Minimum Gauge
(in amps) Up to 4ft. 4 to 7ft. 7 to 10ft. 10 to 13ft. 13 to 16ft. 16 to 19ft. 19 to 22ft. 22 to 28ft.
50-65 8 8 6 4 4 4 4 2
65-85 6 6 4 4 2 2 2 0
85-105 6 6 4 2 2 2 2 0
105-125 4 4 4 2 2 0 0 0
125-150 2 2 2 2 0 0 0 00
150-200 0 0 0 0 00 00 00 000
200-250 00 00 00 000 000 000 000 0000
300-up 000 000 000 0000 0000 0000 0000 00000
Total Current Draw Length Of Wire To Be Run
Your New! PCX™ amplifier has a TC-X Crossover ( Total Control X-over © ) (See
page 19 for crossover Detent Chart). 12dB per octave phase correlated crossover
built in to provide superior system flexibility without the added expense and
i n s t a l l a t i o n of an outboard crossover. The speaker outputs of your amplifier are
high-pass, low-pass, or all-pass according to the HP/LP/Full switch on the front
endplate. You would choose low pass (switch middle) to use this amp for sub-
woofers, choose high pass (switch left), or full (switch right) to use this amp for full
range speakers.
The RCAoutputs are controlled by a separate HP/LP/Full switch, and are always
independent of the speaker output crossover. As well as being able to independently
select HP/LP/Full, your new
P C X ™ amplifier allows independent selection of
frequencies from 30-4kHz (See page 19).
NOTE: The System Diagrams beginning on page 18 show several ways to use
the virtually unlimited
PCX™ amplifiers internal crossovers in your system.
PCX 1250
Front - 12dB/Octave, Detented; HP/LP/Full; 30-4kHz
Rear - 12dB/Octave, Detented; HP/LP/Full; 30-4kHz;
Subsonic - 12dB/Octave, Detented; High Pass; 5-80Hz
QBASS - on Front Channel - up to 12db boost @ 40Hz.
PCX 1500
Front - 12dB/Octave, Detented HP/LP/Full; 30-4kHz
Output - 12dB/Octave, Detented; HP/LP/Full; 30-4kHz
Subsonic - 12dB/Octave Detented; High Pass; 5-80Hz
QBASS PLUS - on Front Channel - up to 18db boost @ 30, 36, 44, 60Hz.
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