Crest Audio CPX 1500 help.
Read the manual!
The Bridge mode on stereo amplifiers is often misunderstood relating to actual operation and usage. In basic terms, when a 2-channel amplifier is operated in the Bridge mode, it is converted into a single-channel unit with a power rating equal to the sum of the power rating for each channel, at a load of twice that of the single- channel rating. For example, the CPX 1500 is rated at 750 watts RMS per channel into 2 ohms. The Bridge rating is 1500 watts RMS into 4 ohms (minimum load). Bridge mode operation is accomplished by placing the MODE switch in the BRIDGE position, using only the BRIDGE Speakon connector or the red binding posts for the output, and using the CHANNEL A input. All CHANNEL B input func-tions are defeated and serve no purpose now. Bridge mode operation can be used to drive sound distribution systems in very large public address applications. Another common use for the Bridge mode is in subwoofer applications where very high power levels are required to reproduce extremely low frequencies with ade- quate headroom. Such enclosures usually contain 2 or 4 loudspeakers to handle the power levels involved. For Bridge mode usage, the enclosure impedance must be 4 or 8 ohms. Never below 4 ohms.