CDT SQA-4140 is a superb four-channel amp constructed with 46Hz-3.5kHz variable 24db crossovers. The amplifiers are logically grouped into pairs for bridging and for the routing of filtered input signals appropriate for each of many configurations possible. Amplifiers 2 and 4 of pairs, 1+2 and 3+4 operate with the signal inverted allowing the choice between individual and bridge mode to be made simply by changing the speaker connections. A dedicated four-channel mixer for all inputs may be selected within the system also. Two input sensitivity levels provides for each pair of amplifiers. Amplifier inputs 3+4 can be filtered to include band-pass and bass EQ (up to 18dB bass-boost at 44Hz) and may optionally be routed to all four, amplifier channels. There are 54 basic switch configurations and many connection schematics allowing almost any installation to be configured.