Front panel controls View larger Front Panel Controls CD/Radio Selector: This button permits you to select the equalizer input source. The unit features separate rear panel RCA inputs for radio and CD/DVD players.Illumination Selector: This button permits you to select the color of the front panel illumination.Master Volume Control: Use this control to adjust the overall output volume level.Fader: Use this control to balance the sound level between front and rear speakers as desired.Subwoofer Volume: This control permits you to increase or decrease the output level of the subwoofer channel.Subwoofer Frequency: Use this knob to set the crossover frequency for the subwoofer output channel (it is for a lowpass filter).Boost/Cut Controls: Each of these controls represents a range of frequencies surrounding a center frequency to cover the audio spectrum from subwoofer to treble. Adjust these controls to suit your taste and listening environment. Each center frequency can be adjusted +/- 18 dB. Specifications EQ center frequencies: 60Hz, 150Hz, 400Hz, 1kHz, 3kHz, 6kHz, 15kHzEqualization range: (boost/cut) +/- 12dBFrequency response: 20 Hz – 20kHzSubwoofer crossover frequency: variable 30-20HzSignal to noise ratio: 60 dBEqualizer THD: less than 0.05%Subwoofer channel THD: less than 0.05%Channel separation: 45 dBPower supply: 10-16V negative groundOutput voltage (subwoofer channel only): 1.5VDimensions: 6.8” W x 4.25” D x 1.1” H Top panel controls View larger Top Panel ControlsRadio and CD Input Gain ControlsThese controls permit you to balance the input gain from your input sources independently.Phase Shift Selector: Select either 0º or 180º to correct for time alignment issues in your audio system. How An Equalizer Is Used The EQ1208 graphic equalizer is a high-fidelity signal processor/preamplifier that that allows you to graphically view and individually control a number of different frequency bands in a stereophonic system. It is intended for use in a car audio system which includes amplifiers in the signal path after the equalizer, and provides front, rear, and subwoofer low level outputs via RCA connectors. The EQ1208 consists of several audio filters, each centered at a specific frequency in the audio range. It enables you to cut or boost the output level by up to 18 decibels as desired at the following frequencies: 40Hz, 150Hz, 1kHz, or 20kHz. The EQ1208 also features a subwoofer channel with an independent crossover control. The crossover can be set from 30Hz to 250Hz. Any signal below the frequency setting will be sent to the subwoofer outputs, allowing you to optimize the sound to suit your particular subwoofer setup. Use of the subwoofer channel is optional.