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Dual 31-Band Graphic Equalizer with Sub Out
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In Stock This item should ship tomorrow (12/1/2015) if ordered within 16 hours 17 minutes

Dual 31-Band Graphic Equalizer with Sub Out

Get extra fine control over the shape your audio signal using this Dual 31-Band Graphic Equalizer with Subwoofer Output from Monoprice!

This professional equalizer is the perfect addition to a recording studio, live performance, DJ station, or even a home theater setup! It features three input options: balanced XLR, balanced 1/4" TRS, and unbalanced RCA. It also features a balanced XLR subwoofer output with a variable crossover from 50 ~ 250 Hz and -∞ ~ +10dB gain, so you can truly hear frequencies down to 20 Hz.

The EQ boasts an incredibly clean signal, with a frequency response of 20 Hz ~ 50 kHz, a THD of less than 0.01%, and a massive 110dB signal-to-noise ratio! A switch on the back panel allows you to select whether the signal ground is tied to the AC input/chassis ground or not. This is particularly useful for eliminating hum when using unbalanced RCA connections, such as for use in a home theater setup.

Each channel has independent controls and LED indicators, allowing the EQ to serve as either two mono equalizers or as a single stereo equalizer. Red and green LEDs on the front panel indicate the clipping status for the input and output for each channel, so you can fine tune your audio signal for peak performance.

The amount of signal variation for each channel is independently switchable between ±6dB and ±15dB. Each channel features a 40 Hz High Pass and a 16 kHz Low Pass filters, an EQ on/off switch, and input level controls (-∞ ~ +6dB).

It can be mounted in a standard 19-inch equipment rack or can be used as a stand-alone audio component. The following table shows the frequency points for each of the 31 sliders:

20 Hz125 Hz800 Hz5 kHz
25 Hz160 Hz1 kHz6.3 kHz
31.5 Hz200 Hz1.25 kHz8 kHz
40 Hz250 Hz1.6 kHz10 kHz
50 Hz315 Hz2 kHz12.5 kHz
63 Hz400 Hz2.5 kHz16 kHz
80 Hz500 Hz3.15 kHz20 kHz
100 Hz630 Hz4 kHz 


  • Easy to operate front panel controls
  • Constant Q circuitry with a 3% center frequency accuracy
  • Control range selectable: ±6dB or ±15dB
  • Active balanced and unbalanced input and output connectors
  • Variable input level control
  • Input and output signal clipping indicators
  • Ground "Lift" switch to disconnect signal ground from the chassis ground
  • Dual voltage support, accepts 100~240 VAC, 50/60 Hz input
  • Robust and compact design
  • Manufactured under QS9000, VDA6.1 certified management system
  • Includes dedicated balanced XLR subwoofer output
  • Variable subwoofer crossover and gain controls

Support Files:

Model 615031
Type 2x 31-band, 1/3 octave
Rack Spacing 2U
Slider Travel 20mm with positive center detent
Range ±6dB or ±15dB selectable
Input Connections Active balanced XLR and 1/4" TRS
Unbalanced RCA
Input Impedance 20kΩ (balanced)
15kΩ unbalanced
Maximum Input Level 14dBu
Output Connections Active balanced XLR and 1/4" TRS
Unbalanced RCA
Subwoofer Output Active balanced XLR
Frequency: 50 ~ 250 Hz
Output Impedance < 600Ω
High Pass Filter 40 Hz (12dB/octave)
Low Pass Filter 16 kHz (12dB/octave)
Frequency Response 20 Hz ~ 50 kHz (-1.5dBu)
Total Harmonic Distortion < 0.01% (@ 1kHz, all VR at 0dB)
Signal-to-Noise Ratio > 110dB
Power Source 95 ~ 120 VAC, 60 Hz
220 ~ 240 VAC, 50/60 Hz
Power Consumption 18 watts (maximum)
Dimensions 19.0" x 8.7" x 3.5" (483 x 220 x 88 mm)

4 Reviews

75% of the reviewers recommend this product


Great Stereo EQ, for BASIC use, and SQ

  • Arcygenical,
  •  Oakville, ON 
  • 11/30/2015 4:47:44 PM

Pros: Floating Ground Option, and secondary ground point.
XLR, TRS and Unbalanced RCA In and out.
Separate Sub Channel out, that takes bridged input, no Y cables needed.
20hz control for the low end is wonderful as a subsonic filter OR a bass booster depending on application.
Decent subwoofer separation with variable lowpass.
Low Power Consumption
Nice controls, smooth actuation, nice knobs.

Cons: Subwoofer frequency gain selector range is 50hz-250hz, is terrible. Most subs play below 50hz, should be able to Select gain to 30-ish hz.
DECENT power-on and off pop noise injected to input. BE CAREFUL.
LEDs are very bright.
Highpass and Lowpass filter buttons on main channels are extremely weak. Very little filtering.

I'm going to rate this as a 9/10 because it does BASIC EQ functions very, very well. It lacks in some areas, especially compared to higher priced options with more features. However, as an actual stereo EQ, it does very well.

Input and Output options are great. Rackmounting is great. Band peak frequencies are standard, and well chosen. Q values are good, overlap is fairly decent. Gain select (6db vs 13db) is useful. Input and output options are flexible. +/-6db preamp gain, that cuts to -infinity is adequate. Signal path is preserved when the unit is powered off (this is great). Unit consumes around 15w during operation and doesn't warm much to the touch. Half rack size is great for cable routing.

There's a very decent power-on and off pop, so be careful if gains aren't set well. As mentioned, the subwoofer gain selector frequency is too high. The highpass and lowpass filters for the main stereo EQ are very weak (little filtering, range too narrow). LEDs are too bright (easily fixed).

All facts considered, the EQ sounds great for the ~110$ price point. Injects no noise into the stream over XLR or TRS, flexible grounding and input/output options are helpful, good control (knob/slider) feel, good frequency points, good frequency overlap and slider Q width.

I havn't found a similar sounding EQ for the same price. Behringer EQ models and ebay EQ models in the same price range don't compare, although they may have more features.

PS: being able to drive dual 12" woofers tuned to 23hz, with +6db on the 20hz band is nearly life-changing.

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  • nuel rosson,
  •  silver city, NM 
  • 6/28/2015 2:39:18 PM

Pros: Just about everything is very good to excellent.

Cons: None really....only way it could be better is if it were FREE!!

Excellent product excellent's all good.

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Nearly destroyed $4000 speakers

  • Audiontoxication,
  •  Irvine, CA 
  • 6/1/2015 7:40:31 PM

Pros: It kinda works as an EQ. Really really noisy though.

Cons: Nearly blew out my Altec Lansing A7-500's. Seriously, it was like a gunshot. The EQ had only been run for about 3 hours, TOTAL.

This EQ just put a huge pop through my system. Easily beyond 120dB. Like a gunshot! My 125wpc amp registered full peak on both channels. There was no signal going through the system at the time, nor was anybody doing anything in the room, in fact nobody was in the room. We were standing just outside the room. Also entire system is conditioned by a Furman power conditioner, it wasn't dirty power and this was the only change in the system in the last few months. After the giant pop when I turned the amp back on I got a bunch of noise, pulled the input levels on the eq down and no change. Turned off the eq and powered the amp back up.......silence.

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nice eq, great value

  • Griffster,
  •  Fort Collins, CO 
  • 11/6/2014 11:03:09 PM

Pros: Balanced and RCA ins/outs for channels and sub
Passive relays that keep the signal path alive even when the power is off
Smooth action on the sliders, with a small slider parking notch at the 0db middle line
Soft start on power ononly a barely audible tick is heard through the outputs

Cons: None so far

I won't rehash the pros, except that I'm very glad the EQ doesn't have to stay powered on to keep the in/out signal path alive! Even when it is powered on, there are bypass buttons that trip these relays if you choose. Sound is VERY clean. If you love the old school analog EQs for customizing your sound, this is an unbeatable value. I am not using the sub outs at this time.

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