2-Ch. Amplifier - 3-Ch. Mode
It is possible to run the 2Ch 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 (as in any bridged situation)
• The active amp crossovers are not used in this system
A 3-Way hookup requires a coil on the woofer and capacitors on the highs to act as a
crossover and maintain correct impedance. Consult the speaker manufacturer for correct
cap and coil values.
X-OVER
WF
WF
TW
TW
X-OVER
2 OHM MIN LOAD
4 OHM
MIN LOAD
15
14
Speaker Wiring of the ST-X SQ III Amplifiers
The Very Basics
No speaker wires can be shorted to, or touching either ground or each other. This will put
the amp into protect and may damage the amplifier. When bridging the left and right
channels of any ST-X SQ III amplifier, you use the left channel (Ch1) positive and the right
channel (Ch2) negative, as indicated on the chassis by the speaker terminals
2-Ch. Amplifer - Stereo Mode
A simple 2 channels hookup for a right and left stereo pair.
2-Ch. Amplifier - Single Channel Mode
This method is used most often to drive a mono woofer but can also be used to run separate
amplifiers for the right and left channel. The ST-X SQ III amplifiers are stable to 2Ω stereo and 4Ω
Mono so the single bridged speaker must be of 4Ω minimum impedance
X-OVER
WF
WF
TW
TW
X-OVER
2 OHM MIN/CH
