PSI Audio A21-M Active Studio Monitor


Perfectly accurate mid field monitor

The A21-M has unmatched impulse response and stereo image.

It 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.


Main Features


280 + 45W

Frequency Range

38Hz – 23kHz

Peak max. SPL@1m


Typical listening distance

1 to 3m

100% Analog – No DSP

Flat frequency response

Perfect stereo image

Class G/H Amplifiers

Individually calibrated

5+1 years warranty

Handmade in Switzerland

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.

“This is one of only a few speakers that I have tested with this good a step response.
Of particular note though is the remarkable step response, which is presumably helped by PSI Audio’s “Compensated Phase Response (CPR) system”. This accurate time response is very rare in this type of speaker but here, PSI Audio has proven that it is possible.”

Keith Holland, Resolution Magazine UK

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.

Flat Response

Potential peak power280 + 45W
Continuous max SPL@1 m106dB
Short term max. SPL@1m110dB
Peak max. SPL@1m121dB
Signal to noise ratio (S/N)98dBA
Bandwidth at -6dB38-23'000Hz
SPL tolerances ±2.0dB
Phase tolerances ± 45 (250 Hz – 20 kHz)deg
Dispersion (H x V)80 x 30deg
Crossover frequency2400Hz
Woofer ext. diam.240mm
Woofer ext. diam.9.4in
W. diaphragm diam.172mm
W. diaphragm diam.6.8in
Tweeter ext. dim.100mm
Tweeter ext. dim.3.9in
T. diaphragm diam.27mm
T. diaphragm diam.1.06in
Dimensions W x H x D250 x 400 x 300mm
Dimensions W x H x D9.9 x 15.8 x 11.9in
Net Weight12.8Kg
Net Weight28.2lbs
Input connector1 x XLR F / 3P
Warranty5 (+1)years

Flat Response

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.

Recording / Producing
Post Production
Home listening

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.

PSI Audio A21-M Active Studio Monitor

Technical Data & Documents

  • compact subwoofer A125-M
    add more power, more low end. Two A125-M perfectly match an A21-M pair.
  • subwoofer A225-M
    more low end (24Hz), more power for your A21-M setup.
  • gig bag
    are you travelling with your A21-M? our gig bag will perfectly protect them and you can easily carry 2 units alone. Handmade in USA.
  • grill protection
    are you using your A21-M in a public space, in broadcast use or at home? protect the tweeter and woofer with our adapted grill.
  • brackets
    do you need to use your A21-M suspended on a wall or on a fixation system? just add a bracket to fix them anywhere.

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 (