[. . . ] Lay commercially available positive cable to the battery and connect using fuse holder. Screw the commercially available negative cable firmly to an interference-free earthing-point (car body bolt, car body sheet, but not to the negative battery pole). Scrape the contact surface of the earthing point until it is blank metal and coat with graphite grease. [. . . ] +12V Controller (GAIN) Using the Gain Controller you can adjust the input sensitivity of the Velocity Power Amplifier to the output voltage of your car radio preamplifier output. When connecting a car radio from other manufacturers the input sensitivity should be adapted in accordance with the specifications of the manufacturer. please note that the Gain Adjust Controller is not designed for volume adjustment!Preamp-INPUT Please use high-quality Velocity cinch/RCA cables for connecting the pre-amp input for right and left channels. preamp-OUTPUT Output for hook-up of an additional amp (for cascaded amplifiers). To make this connection, please use high-quality Velocity Cinch/RCA cables as well. You can also obtain further information on our Velocity Series at our Internet address http://www. In order to do this please select LP and regulate the upper frequencies between 40 Hz and 120 Hz using the crossover frequency control switch. By selecting HP the lower threshold frequency can be varied between 40 Hz and 250 Hz using the relevant crossover frequency controller. to achieve exact acoustic agreement of the frequency divider we recommend that you consult a Velocity dealer. The specifications of the loudspeakers used must be taken into account without fail when carrying out the fine adjustment of the frequency divider. Crossover frequency controller (LP + HP) If the frequency divider (low-pass or high-pass) has been activated using the crossover switch, then it is possible to adjust the crossover frequency of the relative filter between 40 Hz and 250 Hz / 40 Hz and 120 Hz in infinitely variable stages. This controller has no function when the unit is set to Full Range mode. Bass Boost You can adjust the bass output of the Velocity amplifier using the bass boost control. [. . . ] Bass Boost You can adjust the bass output of the Velocity amplifier using the bass boost control. Subsonic Filter The subsonic filter can be used when a subwoofer is connected to the amplifier. It can be activated in order to protect the subwoofer against mechanical overload due to bass frequencies that fall outside our hearing range. [. . . ]