BaseTwo25 is a powered low-frequency extension system with 2 x bass extension towers and 2 x 900W amplifer.

  • Perfectly integrated time and phase-coherent, three-way system, extending all the way down to 20Hz.
  • Extremely robust 25 cm (10”) woofers with matching 25 cm passive radiators mounted in back to back force canceling mode on both sides of the cabinet.
  • Driven by 2 x 900W amplifiers housed in a 2U rack chassis and a stand-alone 1U filtering module with variable-volume control. 


Another step forward…

Modern music is increasingly bass-intensive. To pack the maximum amount of energy into the lowest octave – with no surprises in the playback – a sound engineer needs to hear and feel throughout the whole frequency spectrum.

BaseTwo25 low-frequency extension system fits equally well in any composing, mixing, or mastering setup, where correct reproduction and appreciation of the lowest octave is critical. Amphion’s innovative approach to low-frequency monitoring provides producers, sound engineers, and artists with a completely new perspective to the base.

The BaseTwo25 is a state-of-the-art monitoring solution converting any Amphion two-way studio monitor into a full-range, time and phase-coherent, three-way system. These full-range towers extend all the way down to 20Hz. Each BaseTwo25 has 2 x 25 cm woofers (top) and matching 2 x 25 cm radiators (below) mounted in back to back force-canceling mode on both sides of the cabinet. The system is driven by a 2 x 900W amplifier, and controlled by Amphion’s signature filtering module with a variable-level attenuator.

In addition to providing tight, tuneful bass, BaseTwo25 improves midrange clarity and increases the midrange power-handling abilities of the paired monitors. This is achieved by gradually transferring the low-end frequencies from the monitors to the base extenders.

See more on Amphion’s website.

Additional information
Operating principle

Two-way, passive radiators


1″ (25mm) titanium tweeter
4½” (120mm) aluminum woofer


6 kg (13 lbs)

Crossover point

1600 Hz


84 dB @ 2.83V/1m

Frequency response

78 – 20.000 Hz ±3dB

Power recommendation

20 – 100 W

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