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NEW! 3rd Generation K231 Stereo 3-Way Active Crossover

  • $ 28995

Audiophile Grade Active Crossover

This is the Pre-sales page for the new 3rd generation K231 3-Way or 2-Way Active Crossover.

Upgrades on the Rev 3 unit include:

- The old 'wall-wart' style power supply is replaced with a high quality internal bi-polar analog power supply with a total of 20,000uF of filter caps. This new power supply gives a dramatic improvement in the clarity and definition of the low end.

- Changing to a bi-polar power supply has allowed us to make big improvements in the balanced signal input and output circuitry, improving the noise rejection and resolving potential compatibility issues with some higher end amplifiers

- Better support for selection of 2-way or 3-way crossover modes. We've replaced the old method with a simple slide switch to select the mode. This also fixes an issue where the sub-woofer mixer was not available in 2-way mode.

The upgraded power supply unfortunately has a higher cost, so we're forced to raise the price to $289.95. We plan to begin production shipments on Feb 26, 2018, and we will ship in the sequence of orders received.

<p.s. We will update the photos soon. The Rev 3 unit looks very similar to the previous rev, only the AC power entry and power switch changes.>


Transform Your Sound System with Professional Grade Active Bi-Amping or Tri-Amping.

The K231 Stereo Active Crossover significantly improves the audio quality of your sound system by separating the high, mid and low frequency sounds using ultra low noise, high precision active filter circuits. This allows the use of a separate power amplifier channel for each speaker driver, and eliminates the need for passive crossovers. The result is a massively improved level of clarity and lower distortion of the sound produced. This is called Active Bi-Amping or Tri-Amping.

 K231 Features:

  • Stereo 3-way or 2-Way active crossover for driving separate sub, mid, and tweeter amplifiers
  • Linkwitz-Riley crossover, 4th order 24dB/Octave or 2nd order 12dB/Octave filter slope
  • For Bi-Amping or Tri-Amping your sound system
  • High precision 0.1% filter components for pinpoint XO frequency selection and ultra low distortion
  • Supports 4-way or 5-way operation by cascading two K231's
  • Add a subwoofer to vintage audio equipment lacking LFE outputs
  • All analog design using only the highest quality audiophile grade components:
    • Burr-Brown op-amps ~ Legendary audiophile grade op amps with .00005% Distortion
    • Metalized Polypropylene Film capacitors with 2% precision
    • Metal film resistors with 1% and 0.1% precision
    • ALPS metal film potentiometers
  • Crossover frequency and slope is selected through pluggable 'XO Modules'
  • Wide range of XO Modules are available to support any crossover frequency
  • Optional Sub channel L/R mixer to support a mono sub-woofer channel
  • Supports Balanced and Unbalanced audio signaling
  • Sub, Mid and High output gain front panel adjustments
  • Baffle Step Compensation, with adjustable gain and selectable baffle size ranges
  • Silent On/Off – No loud ‘Thump’ when powering On or Off
  • Made in USA
  • 45 Day No-Hassle Return


  • THD Better than 0.0005%
  • THD+N: Better than 0.0028%
  • IMD : Better than 0.0058%
  • SNR: 120dB
  • Channel Crosstalk Less than -83dB
  • Frequency Response: Linear from 10Hz - 250KHz
  • CMRR (balanced input): Better than 70dB
  • Input Impedance: 33K ohms unbalanced, 66K ohms balanced
  • Input Signal Max: 5.5V
  • Insertion Gain: Adjustable -9dB to +8dB
  • Filter Topology: Linkwitz-Riley, Constant Voltage, 4th Order, 24dB/Octave
  • Enclosure: Aluminum Extruded Chassis
  • Dimensions: 6.5”W x 6.5”D x 2.5”H
  • Shipping Weight: 2.5 lbs
  • Power Supply: Internal Analog Bi-polar, +- 16V, 20,000uF total filter cap
  • AC: 115/230 VAC, standard C13 plug

 Audio Signal Inputs:

  • Stereo Balanced: ¼” TRS Jacks
  • Stereo Unbalanced: RCA jacks

 Audio Signal Outputs:

  • Stereo Balanced High, Mid, Low: ¼” TRS Jacks
  • Stereo Unbalanced High, Mid, Low: RCA Jacks

Preview the K231 User Manual (.pdf)

We stock the following XO Module frequencies. When ordering, please specify your desired 'Sub' and 'Mid/High' crossover frequencies, as well as the slope (12dB or 24dB/octave) in the 'Special Instructions' box on the shopping cart page:

    • Any multiple of 10Hz from 40Hz-200Hz (e.g. 40Hz, 50Hz, 60Hz ... 200Hz)
    • 250Hz, 275Hz, 350Hz, 450Hz
    • Any multiple of 100Hz from 300Hz-4000Hz
    • Any multiple of 500Hz from 4500Hz-10000Hz

You may want to experiment with various crossover frequencies and/or slopes. This can be easily done with the K231. Simply plug in a new XO Module to set a new crossover frequency.

Additional XO Modules are available here

To read more about the advantages of active Bi-Amp'ing ~ 'Making the Case for Active Crossovers vs. Passive'

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