Home » Recording Resources » Featured Reviews » June 2024: Amphion One25A

Breaking with tradition and getting active!


Review by Paul Vnuk Jr.

Amphion Loudspeakers, founded in 1998 by Anssi Hyvönen, is based in Kuopio, Finland. In 2013 Amphion entered the professional studio market, gaining a following for its uniquely styled, radiator-equipped, two-way passive studio monitor designs. Now Amphion breaks many of its long-standing traditions by releasing its first active, three-way radiatorless design: the One25A.

Amphion One 25A displayed at NAMM

Amphion One 25A being displayed at NAMM

Amphion One 25A displayed at NAMM

Amphion One 25A being displayed at NAMM

Amphion and Me

My Amphion journey began in March 2015 when I reviewed the One18. This was followed by the Two18 in March 2016, the One15 and Two15 in November 2016, the FlexBase25 in June 2019 and the BaseTwo25 in September 2021.

In November 2022, I visited Plastic Dog Recording in Los Angeles, CA, to revisit the full Amphion lineup for our A Family of Amphion Monitors Compared. Check out the video here: recordingmag.com/resources/videos

Recently, I traveled back to L.A. and Plastic Dog Recording to check out the new Amphion One25A. Note that Plastic Dog Recording is owned and operated by producer Colin Liebich, the U.S. Amphion rep.

Rules Are Made to Be Broken

The 3-way active One25A remains in sync with the established look of the line—a traditional rectangular MDF cabinet finished in a gently textured matte black with a large, signature white, gently concave Corian waveguide.

The enclosure measures 12.44″ h x 20.07″ w x 19.17″ d, and each One25A weighs an impressive 91lbs.

The One25A is primarily sold in pairs with a left and right model, although you are free to position the woofers inward or outward based on your room and preference.

Three Speakers

The One25A starts with a new 1″ titanium tweeter design recessed in the aforementioned waveguide and set on the same plane as the equally updated 5.25″ aluminum midrange driver. This design creates a super-tight time alignment, which ensures accuracy, focus and a uniform dispersion pattern. The two are crossed over at 2 kHz.

The 10″ aluminum bass driver is crossed over at 100 Hz, and unlike past Amphion low-frequency driver designs, it is fully sealed with no opposing radiator.

Amphion One 25A - Internal ViewOn the Inside

A dual-sealed cabinet design, the bass driver is housed in a separate internal braced sealed chamber from the tweeter and mid-driver. Both are separated by a foam-filled channel capped with a stylish metal grille.

The above design mitigates vibration and controls the cabinet’s resonance. The net result is a better-controlled low-end and, even more importantly, a high degree of top-end clarity by keeping the mid-driver and tweeter free of pressure and interference that could be induced by the bass driver.

Amphion One 25A - controlsLet’s Get Active

The power amp is mounted to the rear of the cabinet rather than recessed inside (when Amphion says sealed cabinet, they mean it). This amp can even be detached, allowing the One25A to be soffit mounted.

The tri-amp design offers 205W each to the tweeter and mid-driver and 700W to the bass driver. The combined output is 105dB max SPL with a 22–55,000 Hz (-3dB) frequency response.

The One25A is a DSP-free, all-analog design. It offers no volume adjustment, and its only control is an 8-step bass response control (+/- 1dB, 2dB, 4dB and 7dB at 20 Hz) designed to compensate for bass build-up due to boundary issues (placement by walls and corners). The control also boosts or attenuates the speaker’s low-frequency response to taste.

This stepped pot is located on the underside of the amp, along with a single XLR input, the IEC power socket and a master power switch.

The One25A also includes a protection circuit in the speaker (located behind the metal grille)  that lights up and pads the signal down rather than muting it like many competing models. It’s worth noting that this protection circuit is not in the actual audio path.

In the Studio

At Plastic Dog Recording, I spent time with the One25A cabinets on the meter bridge of the studio’s Rupert Neve Designs console. We tried woofer-in and woofer-out configurations and preferred the imaging and bass response with the woofers facing inward.

We listened to a range of classic, well-
respected studio tracks in a range of styles, from Donald Fagen’s “Morph The Cat”
to Bruno Mars‘ “24K Magic,“ and Miles Davis‘  “So What” to Sade’s “No Ordinary Love” and more along with many of my own mixes as well as tracks mixed at Plastic Dog.

Sounds Like

In each case, my favorite aspect of every Amphion speaker I have heard to date shined through—a reach-out-and-touch-it three-dimensional width and imaging in the midrange combined with a detailed, airy top-end. The low-end was a combination of bold, bulbous and punchy. This new 3-way design also offered a strong, forward, low-mid response that nicely highlighted the top-end of a bass and kick drum and, equally, the low force of electric guitars.

We tried each setting of the bass response control and were divided. On some tracks, we liked the added control of the -1dB setting; at other times, we preferred the slightly added fullness of adding +1dB.

We also compared the One25A to the Two18 powered by an Amphion Amp700 combined with a FlexBase25 (a package within $200 of the One25A). Being a passive two-way system, given three-way status with the free-standing bass tower, it was not an apples-to-apples comparison. Yet, it was unmistakably the big-richly dimensional Amphion sound in both scenarios.

Overall, I found the One18/FlexBase25 combo a touch more diffuse and deeper, while the One25A was unmistakably bolder and punchier, but such is the hallmark of a sealed cabinet design. Choosing one over the other would come down more to personal taste and space considerations than good or bad.

Toward the end of our sessions, EDM producer Matt Enright stopped by the studio. He was enraptured listening to his own deep-thumping EDM tracks through the One25A, which is a great place to highlight that the One25A monitors have zero need for a sub (outside of an Atmos setup); they will rattle a room with ease. On the flip side, the One25A, more importantly, retains its dimension and punch at normal, moderate listening levels.

Wrap Up

As someone who has heard and used every Amphion model thus far, the One25A more than does the lineup proud on every level, adding a wonderfully punchy and detailed low-end to the company’s well-respected dimension and clarity. That said, this performance level comes with a substantial price tag to match. Simply put, this is “god-like” Amphion status from sound to build to cost.

*Special thanks to Apogee Digital for lending us a Symphony I/O Mk II with the mastering grade 2×6 SE card for this review.

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