background image

 

 

The new ART HD-Series of Precision Graphic Equalizers have been designed 
and engineered to exceed extremely high standards for audio performance and 
functionality. These innovative, high-quality equalizers are perfect for virtually any 
audio application where precision frequency tailoring, reliable performance, rug-
ged design and extremely silent processing is of the utmost priority. 

 
 
 

Active Filter Sections 

The HD-Series of Precision Graphic Equalizers 
feature active filter sections, which incorporate a 
constant-Q design. This constant-Q design, with 
accurate precision center frequencies, ensures  
that the bandwidth of every individual filter will be 
narrow enough to prevent unnecessary interaction 
between filters, yet still create an equalization curve 
wide enough to produce the exact and precise 
processing of audio frequencies the user seeks. 
 

Precision Slide Potentiometers 

The HD-Series of Precision Graphic Equalizers 
utilize 20mm precision slide potentiometers. These 
center-detented, precision faders are graphically 
positioned on ISO center frequencies between 
25Hz-20kHz for model 215, 20Hz to 20kHz for 
models 131 and 231. 

 
Independent Variable Hi and Low Pass Filtering 

In order to deliver superlative performance and 
control, the HD-Series of Precision Graphic Equal-
izers incorporates independent variable Hi Pass 
(low cut) and Low Pass (high cut) filters. Having 
separate and variable precision control for both   
the Hi Pass and Low Pass filters, allow the user to 
custom tailor the audio signal to perfection. 
 
Many competing products only feature shelving 
switches which have a fixed frequency point. 
Others do not have separate filtering for both high 
and low frequencies. These designs do not offer 
the precision or control of the ART HD-Series. 
 

Automatic Relay Bypass 

The HD-Series of Precision Graphic Equalizers 
also feature automatic relay bypass of audio, an 
essential function if power to the unit is lost.  
Rugged construction and solid audio performance 
make these equalizers particularly well suited to 
fixed installation as well as touring live sound 
systems. 

 

Additional Controls and Indicators 

The HD-Series of Precision Graphic Equalizers 
utilize a variable input level control, clip level 
indicator, ground lift switch, and selectable line 
voltage.  
 
Additional features include selectable Scale Switch-
ing - (High Slider Reso/-12dB - or Normal 
Resolution (+/-6dB), active balanced and unbal-
anced input/output connectors, and RFI filtering. 
 
A passive Bypass switch allows for direct compari-
son between the equalized and non-equalized 
signal for each channel. 
 

Multiple Connectivity 

The HD-Series of Precision Graphic Equalizers are 
connectable with a wide variety of audio devices. 
Each unit has three sets of input and output con-
nectors wired in parallel. These connections include 
XLR, 1/4" phone, and Euroblock barrier strip 
connectors. 
 

Durability by Design 

The HD-Series of Precision Graphic Equalizers are 
designed and engineered to be durable and rug-
ged. They are an ideal choice when the need for a 
robust equalizer is of paramount concern. They are 
designed for mounting in a standard 19" equipment 
rack or one of the many rack type portable cases in 
existence. The vertical height is 1.75 inches for the 
HD215 and HD131, and 3.5 inches for the HD231. 
The depth is 7 inches. 
 

Precision and Quality 

When considering quality equalization, the ART HD 
Series of Precision Graphic Equalizers are an 
excellent choice. They deliver extremely precise, 
powerfully flexible and simply great sounding 
equalization, with the quality features and reliable 
design criteria necessary for top-level audio per-
formance.  

 

Summary of Contents for H131

Page 1: ...HD131 SINGLE CHANNEL 31 BAND 1 3 OCTAVE GRAPHIC EQUALIZER HD215 DUAL CHANNEL 15 BAND 2 3 OCTAVE GRAPHIC EQUALIZER HD231 DUAL CHANNEL 31 BAND 1 3 OCTAVE GRAPHIC EQUALIZER ...

Page 2: ... or pinched by items placed upon or against Grounding Do not defeat the grounding and polarization means of the power cord plug Do not remove or tamper with the ground connection on the power cord Moisture To reduce the risk of fire or electrical shock do not expose the unit to moisture or use in damp or wet condi tions Do not place container of liquid on it Heat Do not locate the unit in a place ...

Page 3: ... offer the precision or control of the ART HD Series Automatic Relay Bypass The HD Series of Precision Graphic Equalizers also feature automatic relay bypass of audio an essential function if power to the unit is lost Rugged construction and solid audio performance make these equalizers particularly well suited to fixed installation as well as touring live sound systems Additional Controls and Ind...

Page 4: ... cases available on the market The vertical height is 1 75 inches for the HD131 and HD215 and 3 5 inches for the HD231 The depth is 7 inches POWER CONNECTORS These equalizers have internal power supplies and are designed for operation with 120 or 240 volt as determined by the rear fuse block orientation 50 60Hz mains supply In new installations and portable sound systems or any situation where the...

Page 5: ...NDING The equalizers are equipped with a rear panel Ground Lift switch This should normally be set to the Ground position After set up if your system exhibits excessive hum or buzzing the problem may be a due to a ground differential between your equalizer and other equipment in the same system The Ground Lift switch lets you try several combinations to minimize system hum NOTE ALWAYS TURN YOUR AM...

Page 6: ... signals are within 6dB of clipping If the Clip LED flashes occasionally this is okay but if this LED is steadily on you should reduce the level control INITIAL SET UP Here are some tips to help you with the initial set up 1 Set channel output levels to the center detent 0dB on the front panel 2 Select the Bypass switch to bypass the equalizer Note The red LED is on 3 Set the frequency slide contr...

Page 7: ...s 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 Bypass LED is illuminated this indicates that the unit or chan nel is in the bypass mode Si...

Page 8: ...EQUENCY 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 fre quency noise from preceding instruments or roll off excessive high frequency sounds to obtain...

Page 9: ...and refer servicing to qualified personnel CAUTION After checking the AC supply voltage be sure that the correct fuse is in the fuse holder 0 5Amp for 95 125VAC as well for 220 240VAC The orientation of the fuse holder determines the line voltage range and is labeled on the rear of the holder When changing the fuse make sure that you insert the holder in the correct orientation for your local line...

Page 10: ...and Pin 1 Ground EURO BLOCK HD131 HD 215 HD231 CAUTION Only one input option should be chosen for audio connection at the same time FOR BALANCED CONNECTIONS Wire the connectors 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 wired as follows Phone Jack Connection tip High ring no connection sleev...

Page 11: ...ution to any number of sound problems or creative urges Typical reinforcement application of a two channel equalizer Equalization of a musical instrument Equalization of an effects loop Equalizaton of audio signals from a mixer Mixer Instrument EQ EQ EQ EQ Speaker Speaker Mixer Send Return Amp PreAmp PreAmp Stereo Effects loop Amp Amp Amp P Amp P Amp ...

Page 12: ...ions This warranty does not apply in the event of misuse or abuse of the product or as a result of unauthorized alterations or repairs This warranty is void if the serial number is altered de faced or removed A R T reserves the right to make changes in design or make additions to or improvements upon this product without any obligation to install the same on products previously manufac tured A R T...

Page 13: ...thorization number or questions regarding technical assistance or repairs Customer Service hours are 9 30 AM to 5 00 PM Eastern Time Monday through Friday 4 Pack the unit in its original carton or a reasonable substitute The packing box is not rec ommended as a shipping carton Put the packaged unit in another box for shipping Print the RA number clearly on the outside of the shipping box Print you...

Page 14: ...I filters Yes Passive Bypass Switches Yes Overload LED Threshold 6 dB Below Clipping all filters set to flat High Pass Filter 10 250Hz 12dB Oct Low Pass Filter 3k 40kHz 12dB Oct Frequency Response 20 20kHz 0 5dB THD Noise less than 01 20Hz 20kHz 0dBu IM Distortion SMPTE 0 005 Signal to Noise Ratio greater than 98dB Ref 0dBu Balanced HD215 greater than 95dB Ref 0dBu Balanced HD131 231 20Hz 20kHz un...

Page 15: ...15 ...

Page 16: ... Voice 585 436 3942 Fax www artproaudio com E mail cserve artproaudio com HD SERIES Model HD131 SINGLE CHANNEL 31 BAND 1 3 OCTAVE GRAPHIC EQUALIZER Model HD215 DUAL CHANNEL 15 BAND 2 3 OCTAVE GRAPHIC EQUALIZER Model HD231 DUAL CHANNEL 31 BAND 1 3 OCTAVE GRAPHIC EQUALIZER HD SERIES HD 5004 100 ...

Reviews: