User manual PRECISION POWER PC640.4

[. . . ] · Differential RCA Inputs Isolate 12V/Audio to Ground, Eliminating Ground Loops and Noise. · Optimal Component Layout for Minimal Distortion Induction & Signal Separation. [. . . ] HIGH PASS - This control allows you to pass only frequencies higher than the frequency you choose to the drivers. High Pass crossover filters below 50Hz are also considered "subsonic" filters. Multiplier Switches ­ Sometimes you may need a range that is not within the range supplied by the control potentiometer. In this case, if the amplifier has a multiplier switch, the range can change to accommodate your needs. For example, let's say you have a 4 channel amplifier and you want to put the tweeters (1") on the front channels and the midbass (6. 5") on the rear channels, and use all electronic crossovers. The low pass, if it as two ranges, may be from 50-800Hz which is not high enough. By using the multiplier switch, that same control can change the range from 50Hz-800Hz to 250Hz-4kHz. If this doesn't make sense and you do not understand frequencies clearly, PLEASE TAKE YOUR AMP TO A PROFESSIONAL PRECISION POWER DEALER!Bass EQ ­ This circuit allows you to choose a frequency between 30Hz and 90Hz and boost that frequency by 0-12dB. <10> Crossovers(continued. . ) Xover Mode Switch ­ Select HP/FR for High Pass / Full Range and only the HIGH PASS functions will work. The High Pass filter is ne ver off, but can be set to 15Hz which passes the entire audible spectrum to be reproduced. If you select LP/BP for Low Pass and Band Pass, then the LOW PASS function works as well. You can use the Low Pass in conjunction with the always-on High Pass to band pass the signal to the drivers. For example. . . Let's say you have 3-way components consisting of a 1" tweeter, 4" midrange and a 6. 5" midbass. You can set the midbass to play just the midbass frequencies by setting the LOW PASS to 400Hz and setting the high pass to 60Hz. [. . . ] Phase Switch ­ This switch changes the phase of the woofer from 0 to 180 degrees. Subsonic ­ The Subsonic Filter protects your subwoofers from playing frequencies below the physical limitations of the woofer, or that are beyond the human hearing capabilities. [. . . ]