
A21-M
Perfectly accurate mid field monitor
Redefine the way you produce!
The A21-M is an astonishing monitor used for the most demanding audio productions, allowing the user to be in full control of the sound image in all regards down to the finest details.

A21-M – THE REFERENCE TWO-WAY MONITOR FOR DEMANDING PROFESSIONALS
The A21-M is PSI Audio’s iconic two-way nearfield/midfield monitor, designed for engineers who require uncompromising accuracy, exceptional dynamics, and a natural, fatigue-free listening experience. It delivers a perfect balance of power, detail, and precision, making it a trusted reference in music production, post-production, broadcast, and immersive audio environments.
Hand-built in Switzerland and individually calibrated to perfection, the A21-M offers stunning stereo imaging, true phase coherence, and fast, controlled transient response. Its power and linearity allow it to work effortlessly as a main LCR monitor in high-end control rooms while remaining compact enough for nearfield use.
MAIN FEATURES
- Power: 280 + 45 W
- Frequency Range: 44Hz – 23kHz
- Peak max. SPL@1m: 115 dB
- Typical listening distance: 0.7 to 2 m
- 100% Analog – No DSP
- Flat Frequency response
- Perfect stereo image
- Handmade tweeter
- Class A/B amplifiers
- Individually calibrated
- 5+1 years warranty
- Handmade in Switzerland



A21-M
Power
280 + 45 W
Frequency Range
38Hz – 23 kHz
Peak max. SPL@1m
121 dB
Listening distance
1 to 3 m
Your success story with the A21-M
Only you know where your story begins, and who knows where it will take you?
With the A21-M, you certainly know what you hear: a precise replica of what the sound was intended to be.
Make sure that little details cannot sneak past you during mixing, the A21-M lays them all bare before you. This quality has earned PSI Audio the respect of sound professionals all around the world. As a large nearfield monitor, the A21-M puts the entire soundstage right before your ears with peculiar precision, as lifelike and natural as a reproduction can possibly be. Stop listening for little mistakes – with the A21-M you just hear them. We must warn you though: once you have experienced the real thing, you will not be able to accept anything less.

“The quality and fundamental accuracy of the A21-M extends all the way through the audio band. Voices and acoustic instruments sound just as they should. Stereo imaging is really sharply focussed and precise. The new tweeter is a success also…”
Phil Ward, Sound on Sound
Perfect Stereo Image
Stereo is more than just volume differences between the left and right channels. Phase relations are paramount to determine the accurate position of a signal in the acoustic space – and hence equally important in the development of PSI Audio speakers. The accurate phase alignment provided by PSI Audio CPR technology recreates the vivid spatial listening experience as it was intended. Instrument placement, reverb envelopes, even compression artefacts are easy to identify with the phase-corrected reproduction of PSI Audio speakers.

Expand the bottom end
While the A21-M already reaches down to 38 Hz, its low end can be extended further by adding one or two subwoofers to the system. An A225-M or a pair of A125-M subwoofers will unleash the full potential of the A21-M at any listening level, translating its accurate reproduction qualities into the lowest registers.

| Data | A21-M | [Unit] |
|---|---|---|
| Potential peak power | 280 + 45 | W |
| Continuous max SPL@1 m | 106 | dB |
| Short term max. SPL@1m | 110 | dB |
| Peak max. SPL@1m | 121 | dB |
| Signal to noise ratio (S/N) | 98 | dBA |
| Bandwidth at -6dB | 38-23'000 | Hz |
| SPL tolerances | ±2.0 | dB |
| Phase tolerances | ± 45 (250 Hz – 20 kHz) | deg |
| Dispersion (H x V) | 80 x 30 | deg |
| System | 2 | ways |
| Crossover frequency | 2400 | Hz |
| Woofer ext. diam. | 240 | mm |
| Woofer ext. diam. | 9.4 | in |
| W. diaphragm diam. | 172 | mm |
| W. diaphragm diam. | 6.8 | in |
| Tweeter ext. dim. | 100 | mm |
| Tweeter ext. dim. | 3.9 | in |
| T. diaphragm diam. | 27 | mm |
| T. diaphragm diam. | 1.06 | in |
| Dimensions W x H x D | 250 x 400 x 300 | mm |
| Dimensions W x H x D | 9.9 x 15.8 x 11.9 | in |
| Net Weight | 12.8 | Kg |
| Net Weight | 28.2 | lbs |
| Input connector | 1 x XLR F / 3P | |
| Warranty | 5 (+1) | years |
Flat Response

Individually tested

Each speaker is individually calibrated in our anechoic chamber and is delivered with its frequency response sheet. A proof of quality.
A21-M – The perfect compact 2-way studio monitor
Sitting comfortably in between typical midfield systems and traditional nearfield monitors, the A21-M packs the punch of the larger speakers while retaining a comfortably compact size. It performs well in both scenarios, making it the perfect solution for studios who require the power of a midfield system without having the space for one.
A21-M – Who is it for?
The A21-M is exceptionally suited to all levels of music production, from the recording/producing stage to mixing and even mastering. Broadcast and post pro applications will also benefit from its outstanding transparency and fidelity.
With its outstanding reach in the low end and its still compact size, the A21-M is both versatile and uncompromising in its approach, making it the perfect candidate for all sorts of studios. You can hardly go wrong with an A21-M.
Handmade in Switzerland
All our products are handcrafted in Switzerland with passion and attention to detail.
Manufacturing by hand allows to match and adjust components so that tolerances cancel each other out instead of building up, as is often the case in industrial production.

Choose your colour
Choose between Studio Red, Metal Black and Pure White.
Cabinets are manufactured with great care and attention from the choice of the wood all the way through to the paintwork.

Technical Data & Documents
What our users say
The A21-M is the best monitor I’ve ever owned. It’s the perfect all-round monitor for mixing no matter which kind of music genres in our studios.
Ben Muehlethaler – B-Note Entertainment GmbH (www.b-note.ch)



