Amphion FlexBase25 Stereo Bass-Extension and Management System

Stereo bass-extension and management system with a separate LFE-channel input and a 2 x 700W amplifier



12-Month Special Financing**


Total control for maximum impact

Amphion’s FlexBase25 in a modern approach to subwoofer design. FlexBase25 is room friendly and equally suited for studio acoustics as well as less-treated home studio environments. It is easy to setup and intuitive to adjust. FlexBase25 is a single box, stereo base extension system, which is placed in the centre line between the main speakers.

Wide adjustment possibilities over crossover frequency (35-260 Hz), subwoofer level, as well as the mono-stereo spread, allow FlexBase25 to address the needs of a rapidly changing landscape of modern music-making. With a turn of a few dials, the system adapts to any task you happen to be working on. It can be fat, fun, and vibey when writing and producing. It will be precise, correct, and analytical when putting the finishing touches on a track or a film score.

FlexBase25 does not work like a conventional subwoofer. It does not only add, it transforms. FlexBase25 turns your 2-way monitor into a 3-way full range system, which increases the monitor’s headroom radically. Pair it with One12 or One15 for an ultra fast, easy to adjust small room full-range system. Place it behind your console and let it blend seamlessly with your One18, Two15 ore Two18 monitor, are located on a meter bridge. When you want to dial in on the midrange the by-pass function allows you to use your monitors for a narrower midrange view.

While FlexBase25 is naturally optimized for Amphion products, it blends well with other studio monitors as well.


  • Variable crossover frequency allows changing the flavor of the system to match the specifics of the various production tasks.
  • Mono/stereo spread adjustment to ensure precise system-integration, even when higher crossover points are used.
  • Fast and simple-to-set-up, easily adapting to a large variety of projects and acoustic environments.



Operating principle
One way closed box, stereo

2 x 25 cm / 10” aluminium

Active 4th-order @ 35-260 Hz


Frequency response
20 Hz – 260 Hz +/-3dB (low pass)
35 Hz – 200 kHz +/-3dB (high pass)

50 kg / 110 lb

Handmade in Finland

Don't see what you're looking for?

We carry all of the top brands for audio and post-production, so don’t hesitate to contact us if you need something specific!

Westlake Pro Card

No Interest if paid in full within 12 Months**

On qualifying purchases made with your Westlake Pro credit card. Interest will be charged to your account from the purchase date if the promotional purchase is not paid in full within 12 Months. Minimum monthly payments required.

**No interest will be charged on the promo purchase if you pay it off, in full, within the promo period. If you do not, interest will be charged on the promo purchase from the purchase date. The required minimum monthly payments may or may not pay off the promo purchase by the end of the promo period. Regular account terms apply to non-promo purchases and, after the promo period ends, to the remaining promo balance. For new accounts: Purchase APR is 29.99%. Minimum interest charge is $2. Existing cardholders: See your credit card agreement terms. Subject to credit approval.

book a consultation

Contact Westlake Pro’s Design Services Group for a free consultation about your next project.

Apply For A Lease From
All Media Capital

Insider Access to Pro Audio's hottest deals, new gear, and free software.

We hate spam. We don’t share your information with any third parties.

Sign up now!