[. . . ] Bolt a standard commercial negative cable to a ground point free of induced noise (car body bolt, body panel) - not to the negative battery pole. Clean the contact surface of the ground point down to bare metal and coat with antiseize graphite petroleum. Integral fuses The integral fuses within the amplifier protect the final stage and the entire electrical system in the event of a fault. This enables the amplifier to be switched on and off with the radio's On/ Off switch. [. . . ] Observe the vehicle manufacturer's safety instructions (regarding airbags, alarm systems, trip computers, vehicle immobilisers). The final stage must be installed professionally for reasons of safety. The mounting surface must be suitable for the screws provided, and must provide firm support. When drilling holes, take care to avoid damage to vehicle components (battery, cables, fuse boxes). The mounting location must also be dry, and provide sufficient ventilation for cooling of the amplifier. Use cable grommets when passing cables through holes with sharp edges. Use loudspeakers with an impedance of 2 to 4 (see table or installation drawing). Do not connect the loudspeakers to ground; only use the terminals provided. The crosssection of the positive and negative cable must be at least 6 mm2. gTA 2100B amplifier The amplifier is suitable for connection to car radios with Cinch connector. Use the Blaupunkt ISO Cinch adapter to connect the amplifier to car radios with ISO connector. Gain control The gain control enables the input sensitivity of the final stage to be matched to the output voltage of your car radio preamp output. Adjust the input sensitivity in accordance with the manufacturer's specifications when connecting the amplifier to other radios. important: Turning the gain control clockwise increases the input sensitivity of the amplifier , and thereby also the volume. The gain control is however not a volume control; an increase in volume is not achieved in the maximum position, even if this subjectively appears to be the case. The system merely increases the volume more quickly when the volume is turned up on the radio. Tri-mode loudspeaker connections GTA amplifiers can be used in a combined mono/stereo mode (Fig. This facility enables the amplifier to be used simultaneously with stereo satellite speakers (mid-range and tweeter) and a mono subwoofer. [. . . ] Note: If the amplifier is to be used in the tri-mode configuration, the crossover frequency selector switch must be set to , , Flat" in order to make the full frequency range available. Stereo mode Max power Mono mode Max power Stereo mode RMS Power Mono mode RMS Power Tri mode Frequency response Signal-to-noise ratio Stabilility Input sensitivity Low-pass filter High-pass filter Bass-Boost Preamp - In / -Out Dimensions D x W x H (mm) 2 x 100 Watt / 4 1 x 400 Watt /4 2 x 50 Watt / 4 2 x 80 Watt / 2 1 x 160 Watt / 4 1 x 200 Watt / 2 10 Hz - 55. GTA 2100B The GTA 2100B has a special subwoofer crossover frequency which can be selected between 40Hz and 160 Hz. The crossover can be bridged by turning the selector switch to the "Flat" position. [. . . ]