User manual ART HQ31

[. . . ] In a live sound system where the HQ EQ is in the path between a microphone and loudspeakers, dominant room modes may be seen as bands with a lot of energy when the sound 2 system gain is increased. These bands with excess energy will brightly illuminate the corresponding led above the offending frequency's fader. These frequencies will generally be the first where feedback is likely to occur. FDC can also be employed as a simple spectrum analyzer along with its primary use with the equalizer. This will allow you to identify "hot" spots ­ area of potential feedback ­ and attenuate accordingly before feedback occurs. Of course, during a musical performance, FDC will help you quickly locate and eliminate feedback if it occurs. Be careful when running a sound system close to its feedback limit. [. . . ] If you do not have enough gain for your needs, switch the range switch to the 12dB setting. If the Clip LED lights continuously, turn down the level control until the LED is off most of the time. FRONT PANEL CONTROLS 1. POWER SWITCH To turn the equalizer ON or OFF, press the upper or lower portion of this button. CAUTION: Always 5 turn on your equalizer BEFORE your power amplifiers are turned on, and always turn off your equalizer AFTER your power amplifiers have been turned off. 2. FILTER LEVEL CONTROLS Each of these sliders controls the output level of each of the 31 (or 15) bandpass filters. A detent at the center position helps center the controls for a flat response. 3. FILTER RANGE SWITCH & INDICATORS The gain range of the filter sliders is switchable (as a group) from +/- 6dB to + /-12dB for maximum boost/cut capability. At 6dB the green LED will illuminate and at 12dB the yellow LED will illuminate. 4. BYPASS SWITCH & CLIP INDICATOR LED Bypass Switch: When the red LED is illuminated, this indicates that the unit or channel is in the bypass mode. Signal is routed directly from the input to the output without passing through any circuit (often referred to as "hard-wire bypass"). Use this switch to compare equalized and unequalized material, or to bypass the EQ section in the event of power loss or unit failure. Clip Indicator: - This red LED illuminates if any section of the equalizer is within 5dB of clipping. Occasional flickering of this LED is acceptable, but if it remains on more than intermittently you should turn down either the equalizer's level controls or reduce the output level of the preceding component to avoid audible distortion. 5. HI PASS FILTER (LOW-CUT FREQUENCY CONTROL) To cut down on unwanted low frequency signals, this control determines the roll-off frequency of the High-Pass Filter (HPF). The roll-off frequency can be adjusted from 10Hz to 250Hz by turning this knob. Because of its high roll-off slope, the HPF can be efficiently used to cut down the "HUM" noise from preceding instruments, or to reduce low frequency resonances, when speakers are installed in an enclosed acoustic environment. 6. LOW PASS FILTER (HIGH-CUT FREQUENCY CONTROL) To cut down on unwanted high frequency signals, this control determines the roll-off frequency of the Low-Pass Filter (LPF). The roll-off frequency can be adjusted from 3kHz to 40kHz by turning the knob. Because of its high roll-off slope, the LPF can be effectively used to cut down the high frequency noise from preceding instruments, or roll-off excessive high frequency sounds to obtain a 6 more natural sound in acoustic situations. 7. LEVEL CONTROL This controls the level of signal coming into the equalizer. Turn this control down if the Clip LED illuminates steadily (meani ng too strong an input signal). Unity gain can be set by turning this knob to the center detent position. Signal level should be kept normalized through the equalizer. That is, the signal level, when bypassed, should be the same (or a little lower) than when active. [. . . ] Print your return shipping address on the outside of the box. 5) Include with your unit: a return shipping address (we cannot ship to a P. O. Box), a copy of your purchase receipt, a daytime phone number, and a description of the problem. 6) Ship only your unit and its power supply (keep your manual!) to: APPLIED RESEARCH AND TECHNOLOGY 215 TREMONT STREET ROCHESTER, NEW YORK 14608 ATTN: REPAIR DEPARTMENT RA# ____________________ 7) Contact our Customer Service department at (716) 436-2720 for your Return Authorization number or questions regarding technical assistance or repairs. [. . . ]