Dual 15-band Graphic EQ

Introduction

Thank you for choosing a Citronic equalizer unit. This product has been designed to deliver professional tone-shaping facilities with reliable and accurate function. In order to achieve the best results from this equipment and avoid damage through misuse, please read and follow these instructions and retain for future reference.

Features

• Switchable Bypass per channel
• Switchable Low Cut filter per channel
• Independent Gain controls
• ±12dB adjustment per band
• Balanced or unbalanced signal path
• LED VU display per channel

Warning

To prevent the risk of fire or electric shock, do not expose any part of the unit to rain or moisture.

If liquids are spilled on the surface, stop using immediately, allow unit to dry out and have checked by qualified personnel before further use.

Avoid impact, extreme pressure or heavy vibration to the unit.

There are no user serviceable parts inside the equalizer– refer all servicing to qualified service personnel.

Safety

• Check that the supplied mains lead is in good condition and the supply voltage is correct.
• Ensure signal leads are of good condition and connected to appropriate inputs/outputs
• Do not allow any foreign particles to enter the console through slider or connector apertures

Placement

• Keep out of direct sunlight and away from heat sources.
• Keep away from damp or dusty environments.
• When rack-mounting, avoid placing heavy units above the unit and ensure all connectors are accessible

Cleaning

• Use a soft cloth with a neutral detergent to clean the casing as required.
• Use a soft brush to clear debris from the control surface.
• Do not use strong solvents for cleaning the unit.

Front Panel

Rear Panel

What is Equalization?

Equalization (or EQ) is so called because its primary function is to accurately “equalize” or balance the frequency profile of a signal for a given application or environment. This is especially noticeable in large rooms, which can emphasise “boominess” in the low frequencies or rooms with soft furnishings, which can absorb a lot of the high frequencies. An equalizer can be set to reduce “boomy” low frequencies or replace lost high frequencies.

At best, human ears can detect sound from 20Hz to 20000Hz (or 20Hz – 20kHz). All natural (and some unnatural) sounds have many harmonics and overtones across the listening spectrum, giving them varying tonal characteristics. We often refer to the lowest frequencies as “Bass” and the highest frequencies as “Treble” but this only describes 2 regions of tone, whereas the listening spectrum could be divided into as many sections as desired in order to give more accurate measurement and manipulation of the sound characteristics.

EQ can also be used as a tool to push a signal forward in a mix or set it further back into the mix by boosting or cutting key mid frequencies, reducing feedback by cutting frequencies which are prone to resonance and boosting specific frequencies to lift certain instruments in a piece of music.

Connection

The unit can be used in 2 configurations…

1. As 2 independent mono graphic equalizers – e.g. for 2 separate

   microphones on channel inserts

2. As a stereo left & right EQ – e.g. as a main L+R EQ on master

   inserts or between the mixer and amp.

Before connecting to an amplifier or other equipment, turn down all volume controls to avoid loud noises which may cause damage to other equipment. Always switch amplifier power on last in line with volume levels down. Use good quality 6.3mm jack or XLR signal leads to connect the equalizer to allied equipment. The unit can be used as 2 independent mono equalizers (e.g. for 2 microphone channels, requiring specific EQ profiles). Connect mains power via the IEC (ensuring lead is in good condition and the voltage selector is same as the supply voltage) and switch the POWER on.

Operation

Begin with all frequency sliders and the GAIN controls in the centre position (no boost or cut) at 0dB.
Switch the “IN/OUT” button to IN and the respective LED will light.
Adjust each frequency in turn to acquire the best response and reduce any problem frequencies.

Bear in mind that many loudspeakers cannot reproduce frequencies down as far as 20Hz and that the energy from the amplifier at these low frequencies is wasted as heat in the speaker coil. Therefore, the “LOW CUT” may be preferred to be on in sound reinforcement scenarios.

Also, with live PA situations, the crossover point between subs and mid-top cabs can generate phase problems which may be alleviated by reducing frequencies around this point.

Extremely high frequencies are often not feasible for live sound systems, due to the limitations of microphones and loudspeakers (and most people’s ears) and 20kHz may be reduced to save wasted amplifier energy at these high frequencies.

For whichever particular application, experimentation and practice will eventually give the best results from your equalizer.

Troubleshooting