ART EQ351

Product overview

The ART EQ351 is a single-channel 31-band graphic equaliser in a 1U rackmount, with variable high-pass and low-pass filters, a switchable 6 or 12 dB range and a bypass control.

ART 300-Series graphic equalisers are designed for live sound, studio and installation audio applications to provide intuitive sound shaping, versatile features and silent operation. The EQ351 is a single-channel 31-band EQ with a switchable range of 6 or 12 dB, for subtle shaping or dramatic sculpting of your sound. The high-pass and low-pass filters can quickly dial in the optimal bass and treble response, and the bypass control lets you compare the dry and processed signals for easy reference. The rear panel has balanced XLR, balanced 1/4 inch TRS and unbalanced RCA connectors, so the EQ351 is easy to integrate into any system, and a ground lift switch helps to eliminate hum.

Key features

• 31-band graphic EQ, 1/3 octave, ISO spacing, constant-Q filters
• 20 mm sliders with centre detent
• Switchable 6 dB or 12 dB range
• Variable high-pass and low-pass filters
• Master level control
• Hard-wire bypass and clip indicator
• Balanced XLR and 1/4 inch TRS inputs and outputs
• Unbalanced RCA input and output
• Ground lift switch
• 1U rackmount

Constant-Q filters and sliders

ART's EQ300 Series uses active constant-Q filter sections with accurate centre frequencies, so each filter's bandwidth is narrow enough to prevent unnecessary interaction between filters while still giving a wide enough equalisation curve. The 20 mm centre-detented precision faders sit on ISO centre frequencies from 20 Hz to 20 kHz, and the Range switch sets them to ±6 dB (green LED) or ±12 dB (yellow LED).

High-pass and low-pass filters

The Hi Pass control sets a low cut from 10 Hz to 250 Hz to reduce hum, low frequency noise, resonances and rumble; the Low Pass control sets a high cut from 3 kHz to 40 kHz to reduce high frequency noise or excessive high frequencies. Both filters roll off at 12 dB per octave.

Bypass, clip and level

The Bypass switch routes the signal directly from input to output without passing through any circuitry, for comparing equalised and unequalised material. The red clip LED lights when any section is within 6 dB of clipping, and the Level control sets the output from off to +6 dB.

Connections and power

Three sets of input and output connectors are wired in parallel: balanced XLR, balanced (or unbalanced) 1/4 inch TRS and unbalanced RCA; only one input should be used at a time. A Ground Lift switch disconnects signal ground from mains and chassis earth to cure hum from ground loops. ART's user's guide gives switchable mains operation, 95-130 V AC 50/60 Hz or 190-250 V AC 50 Hz, set with the rear line voltage switch.

In the box

• EQ351 31-band graphic equaliser

ART EQ351: frequently asked questions

Is the EQ351 mono or stereo?

It is a single-channel (mono) 31-band equaliser.

What do the high-pass and low-pass filters cover?

High-pass 10 Hz to 250 Hz and low-pass 3 kHz to 40 kHz, each at 12 dB per octave.

Can it run on 230 V mains?

ART's user's guide lists switchable operation at 95-130 V AC 50/60 Hz or 190-250 V AC 50 Hz, selected with the rear line voltage switch.

Can I connect a microphone directly?

No. ART states that microphones and instrument pickups need a preamp to reach line level before the equaliser.

Where can I buy the ART EQ351 in India?

The ART EQ351 is available from Shivansh Electronics, Kolkata, West Bengal, India, with delivery across India.

Workflow 1: Mono PA or monitor equalisation

Live sound engineers equalising a mono speaker system or monitor mix.

Connections

Setup

1. Set the level to the centre detent, select Bypass and centre the sliders.
2. Set the hi pass to 10 Hz and the low pass to 40 kHz, select ±6 dB.
3. Release Bypass and start equalising.

Tip: Switch to ±12 dB only if more control is needed.

Workflow 2: Cutting rumble and hum

Systems with low frequency noise or resonances.

Connections

Setup

1. Raise the Hi Pass control until the rumble or hum is reduced.

Tip: The high-pass filter covers 10 Hz to 250 Hz at 12 dB per octave.

Workflow 3: Taming harsh high frequencies

Rooms or sources with excessive high frequency content.

Connections

Setup

1. Lower the Low Pass control from 40 kHz until the top end sounds natural.

Tip: The low-pass filter covers 3 kHz to 40 kHz.

Workflow 4: Equalising a musical instrument

Players shaping an instrument's tone through a preamp.

Connections

Setup

1. Bring the instrument up to line level with a preamp.
2. Shape the tone with the sliders.

Tip: ART shows instrument equalisation among the applications in its user's guide.

Workflow 5: Equalising an effects loop

Engineers shaping an effect return.

Connections

Setup

1. Insert the EQ351 in the effects loop.
2. Use Bypass to compare.

Tip: Effects loop equalisation is one of ART's illustrated applications.

Workflow 6: Avoiding clipping

Any system using the EQ351.

Connections

Setup

1. Watch the red clip LED: occasional flicker is acceptable.
2. If it stays on, reduce the level of the preceding equipment or the EQ's Level control.

Tip: The clip LED lights 6 dB below clipping.