zapco Z-150.4 II Owner's Manual page 15

4Ω ~ 8Ω
Note: Take note that 4 Ohms is the minimum load when bridging, since each channel will see
only 1/2 the load (2 ohms). Do not bridge with a 2Ω woofer
It is possible to run the 2-Channel amps in "3-channel" mode by running a pair of
speakers for the mids and highs on left and right channels, and at the same time
run a woofer bridged between the L+ and R- terminals as shown. However, since
each channel will see 1/2 the impedance of the woofer you must use a woofer of
no less than 4Ω. The amplifier sees impedance by frequency, so you can have two
2Ω loads but you must use a passive crossover on each speaker in the three channel
mode. With the crossovers in the line, the amplifier will always see a minimum
load of 2Ω on each channel at all frequencies.
• Main speakers can be 2Ω ~ 4Ω
• Woofer can be 4Ω ~ 8Ω but cannot be less than 4Ω
• HP crossover can be FULL or can be HPF to be used between 15Hz and 25Hz
as sub sonic filter
• LP crossover must be set to FULL
• All actual crossover functions will be done by the passive crossovers in the lines
2Ω ~ 4Ω
2Ω ~ 4Ω
4Ω ~ 8Ω
3Ch Mode
X-O
X-O
X-O
13