The Amphion Flexbase 25 Base System is a versatile stereo bass extension and management system designed to transform your 2‑way monitors into a powerful, full‑range 3‑way setup. Rather than behaving like a conventional mono sub, Flexbase 25 uses a single, centrally placed stereo bass unit that preserves stereo information down into the lowest octaves and integrates seamlessly with your main speakers.
 
At the heart of the system is the FlexBase25 enclosure, a sealed, one‑way box equipped with two 10" aluminium woofers mounted on the left and right sides. The system is powered by the FlexAmp1200, a dedicated 2 x 700 W stereo amplifier that also houses Amphion’s proprietary filter module. Together they deliver deep, controlled bass from around 20 Hz upwards, while maintaining the time and phase coherence that Amphion monitoring is known for.
 
The crossover frequency is continuously adjustable between 35 and 260 Hz, allowing you to tailor the behaviour of the system to different tasks and speaker sizes. You can fine‑tune the sub level and adjust the mono‑to‑stereo spread of the low frequencies, from pure mono through to fully stereo bass, so Flexbase 25 works equally well for tight, centre‑focused low end and wide, immersive productions. A dedicated LFE input with +10 dB sensitivity gives you separate control over the .1 channel in film, TV and Atmos‑style setups, without forcing you into a fixed low‑pass filter.
Placed on the centre line between your main monitors, the Flexbase 25 Base System is easy to position and simple to integrate: it sits inline between your interface or monitor controller and your speakers, handling crossover and bass management while your mains take care of the mid and high frequencies. Paired with Amphion monitors such as One12, One15, One18 or even larger systems, it significantly increases headroom, improves low‑end translation and lets you make faster, more confident decisions about kick, bass and overall punch.