HQ-31 SINGLE CHANNEL 31 BAND 1/3 OCTAVE GRAPHIC EQUALIZER HQ-15 DUAL CHANNEL 15 BAND 2/3 OCTAVE GRAPHIC EQUALIZER USER’S GUIDE
GENERAL INFORMATION SINGLE CHANNEL 31 BAND 1/3 OCTAVE GRAPHIC EQUALIZER WITH FDC Features constant Q circuitry with a 3% center freque ncy accuracy.
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.
Only one of the 3 inputs should be used per channel. Any combination of output connectors may be used. XLR connections are balanced with pin 2 is High (+), pin 3 is Low (-), and pin 1 is ground. 1/4" Phone connections may be used balanced or unbalanced. When balanced, the tip is High (+), the ring is low (-) and the sleeve is ground. To use unbalanced use a mono phone cable, this will automatically ground the ring to the sleeve. RCA connections are always unbalanced.
to the range selection switch there is a n output level control potentiometer. The level control operates between off and +6dB. Note: If there is too much gain your equalizer has a red LED Clip indicator. The Clip LED illuminates when signals reach 5dB prior to clipping. If this situation occurs and the overload LED flashes occasionally, this is okay, but if the overload LED is steadily on you must readjust the level control. Here are some tips to help you with the initial set up: 1.
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.
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.
10. POWER CORD This cord is used connect the AC power source to your equalizer. CAUTION: Equipment for USA installation includes a captive power cord with a three pin polarized plug. DO NOT REMOVE THE CENTER GROUNDING PIN. 11. FUSE HOLDER This fuse holder contains the AC primary fuse. This fuse should be replaced with the same type fuse if it is blown. If they continuously blow, stop replacing fuses and refer servicing to qualified personnel.
FOR BALANCED CONNECTIONS Wire the connector’s as follows: Phone Jack Connection tip = high ring = low sleeve = ground FOR UNBALANCED CONNECTIONS Use 1/4 inch tip-ring-sleeve or mono phone plug connectors or RCA phone jack connectors wired as follows: Phone Jack Connection tip = high ring = no connection sleeve = ground 9
APPLICATIONS Graphic equalizers may be used wherever modification of the frequency contour of a sound system is needed. A graphic equalizer is a solution to any number of sound problems or creative urges.
WARRANTY INFORMATION Limited Warranty Applied Research and Technology will provide warranty and service for this unit in accordance with the following warrants: Applied Research and Technology (A R T) warrants to the original purchaser that this product and the components thereof will be free from defects in workmanship and materials for a period of one year from the date of purchase.
SERVICE The following information is provided in the unlikely event that your unit requires service. 1) Be sure that the unit is the cause of the problem. Check to make sure the unit has power supplied, all cables are connected correctly, and the cables themselves are in working condition. 2) If you find the unit to be at fault, write down a complete description of the problem, including how and when the problem occurs. Please write down a description of your complete setup before calling Customer Service.
SPECIFICATIONS EQUALIZER Bands Type Accuracy Travel Range INPUTS Type Connectors Impedance Maximum Level OUTPUTS Type Connectors Impedance Maximum Level OVERALL GAIN RANGE RFI filters Passive Bypass Switches Overload LED Threshold High Pass Filter Low Pass Filter Frequency Response THD + Noise IM Distortion (SMPTE) Signal to Noise Ratio Channel Separation Common Mode Rejection 1*31, 1/3 Octave ISO Spacing From 20Hz to 20kHz. (HQ-31) 2*15, 2/3 Octave ISO Spacing From 25Hz to 16kHz.
APPLIED RESEARCH & TECHNOLOGY 215 TREMONT STREET ROCHESTER, NEW YORK 14608 USA (716) 436-2720 – Voice (716) 436-3942 – Fax www.artproaudio.com E-mail: cserve@artproaudio.
