Hardware Reviews

Audio Physic Codex reveals hidden depths

audio physic codex speaker review https://the-ear.net

Audio Physic Codex loudspeakers

I last reviewed Audio Physic speakers some twenty-odd years ago. I remember that this German company had novel ways of solving problems, and the speakers were so good I was sad to see them go. In the intervening years their presence had all but faded away in the UK, so they are little known here, but recently Cyrus has taken on distribution, with a mission to re-build the brand. With memories of the Audio Physic Spark I heard all those years ago, I rather fancied reviewing a floorstander, and the Codex was available in-between exhibitions and demonstrations.

At 119.5cm high the Codex are quite large and commensurately heavy. They are available in glass clad paint finishes or wood veneer: this pair were in high-gloss wood, finished to a very high standard. Apparently several layers of paint and polishing go into each pair, and the speakers gleam.

But this is not merely cosmetic, Audio Physic’s unconventional approach to speaker design starts on the outside and goes right through to the rear terminals and feet. Instead of veneering a conventional MDF cabinet, Audio Physic have adopted a multi-layer construction, with panels glued to the outside using a permanently elastic damping layer. The upper part of the front is made from a detachable glass/Valchromat baffle, held in place by magnets, this conceals the drive unit frames, presenting a neat, uncluttered face to the world (an optional grille is available) . Internally, there are multiple bracings, using either open-cell honeycomb panels, or ceramic foam, these are not only extremely rigid but have an open, porous structure which leaves the maximum space for the drivers to breathe in.

audio physic codex speaker review https://the-ear.net

Attention to mechanical vibration even extends to the WBT Nextgen cable terminals, which are mechanically decoupled from the loudspeaker cabinet. Additionally, the feet contain opposing magnets which suspend the speakers and isolate them from the floor (these are an optional extra and not supplied as standard). To avoid electromagnetic interaction, each section of the crossover network is mounted close to each respective drive unit, keeping the individual circuits and their inductors far apart.

Bass frequencies are handled by a 10-inch paper-pulp-coned woofer, mounted out of view inside the bottom of cabinet. This only handles frequencies below 100Hz and is claimed to output down to 28Hz via the base of the speaker through a block of ceramic foam, augmented by a slot port formed between the internal cabinet and outer front cladding.

All the other drive units have ceramic coated aluminium CCAC (anodised aluminium) cones of various profiles. The tweeter is, most unusually, not a dome, but a combination of a cone and a dome. The cone is aluminium and of course stiff, with the outer periphery, and termination covered in felt, presumably to help absorb energy, prevent standing waves, and attenuate some of the outer cone’s radiation. However, I was surprised to find that the central dome is made of a soft plastic or rubber material, so will contribute significantly less to the sound and add damping.

audio physic codex speaker review https://the-ear.net
Cyrus and Audio Physic Codex

Also, both tweeter and midrange drivers use techniques which eliminate the need for a rear spider to centre the voice coil in the magnetic gap. Dome tweeters don’t usually need a spider, but cones usually do. So why eliminate this seemingly innocuous item? The problem is that spiders can introduce resonances  and air-borne reflections, which are delayed and sent back through the cone. In addition, non-linear spider stiffness can cause distortion. So, eliminating this one item sounds like a good idea.

Another technique applied to the midrange and tweeter in the Codex is what Audio Physic call ‘active cone damping’. This is a novel method of attaching the surround, which is smaller than the cone, by stretching and releasing it onto the cone’s edge, forming a tight compressive fit which, together with adhesive, damps vibrations. Also, the surround is flat, without the usual ‘U’- shaped roll, which so often creates an anti-resonance, causing suck outs and energy storage leading to audible colouration. It is clear that they have applied a great deal of original thought and novel solutions to overcome common problems and not merely followed the pack.

The mission to eliminate unwanted vibration even extends to the midrange driver chassis, which has a dual-basket construction, with a small contact area between the inner and the outer baskets, and damping to reduce the transfer of vibration between the cone and the cabinet and vice versa.

audio physic codex speaker review https://the-ear.net

Above 100Hz, and below the contribution from the midrange, a rather more conventional 7 inch driver takes over, enabling the woofer to do the ‘heavy lifting,’ and relieving the upper 7 inch  driver from high excursions. Audio Physic claim this split bass arrangement provides more latitude in terms of placement than traditionally designed loudspeakers.

Of course, none of this would amount to a hill of beans if the Codex did not deliver the sonic goods. I had not read any of the design philosophy and novel techniques outlined above, to influence me before I listened. So, apart from fond memories of the Spark, I had no pre-conceptions about the sound of the Codex. They are not exactly inexpensive, so would they be up to the mark?

Sound quality

I should not have had any doubts. From the very first bars of Rimsky Korsakov’s The Tumblers, from The Snow Maiden (Eiji Oue, Minnesota Orchestra Reference Recordings RR906). The music exploded into the room with breathtaking exuberance. Brass instruments sounded wonderful, with that rich shimmering texture when played well, in the Russian style. Bass drum had dramatic impact and depth, and the cymbals crashed convincingly. Instruments of the orchestra were beautifully separated, with a fine sense of depth, breadth and naturalness. And amidst the full power of the orchestra, the tiny triangle was distinct and clear at the rear, and the view of the orchestra was not an intimate close-up, but a really big sound and set a little back, as it would be naturally.

For all the drama and dynamics of this piece, the top end was smooth as butter. Everything was in its place, nothing exaggerated. This was a great start to my listening experience and I can safely say that it continued much in the same vein. To be fair, this is a show-off audiophile recording, so it should be good, but clearly these speakers were capable of tremendous dynamics, deep bass and great subtlety. They were impressive, but in a chameleon-like way, not drawing attention to themselves, but to the music.

Next was Rachmaninov’s Piano Concerto number 3 played by Byron Janis with the London Symphony and number 2, coincidentally, by the Minneapolis Symphony Orchestras, both conducted by Antal Dorati, (Mercury Living presence, recorded in 1960 and 1961). I chose this, not because it’s perfect, which it isn’t, but because it can sound either very good, or uninspiring – depending on the system. The string tone on this recording is not the best – it can sound sour or wiry, but with the Codex in my system, strings were quite velvety  – very presentable and not at all harsh or strident. The Codex tweeter appears to lack any peakiness or exaggeration, delivering a clean extended treble.

audio physic codex speaker review https://the-ear.net

Janos’ piano sounded firm and clear, while the delicate pizzicato strings were distinct. I was struck that these sound contributions merged into one whole experience, with no suggestion of sounds coming from separate sources, and no exaggeration of any one part of the range. The speakers seemed to vanish and are adept at giving convincing results with recordings made in a natural acoustic.

The treble and midranges were particularly fluid, well resolved, yet smooth and sweet given a good source. Likewise, bass delivery lacks any hint of emphasis, lumpiness or boom. If you like crisp treble that highlights high notes and transients, vocals that leap out, or hyper analytical micro-detail, then this might not be your ‘cup of tea’, but to me it just sounded natural. Another observation, was that the Codex never sound metallic or sterile, which can sometimes arise with metal diaphragms. It’s a testament to how well Audio Physic has designed their drive units and diaphragms.

I played so much more music, from different sources through these speakers, just for pure enjoyment, forgetting to make any notes, with streamers including a Moon 390 and Auralic Altair G2.1 feeding a Creek Destiny power amp. However, even from a Skybox via Toslink to the above streamers, or a Burson Conductor 160 DAC into the Creek amplifier, they sounded great. For instance sitting through the BBC’s 60 years of pop music and 60 years of classical, followed by their Northern Soul night with Stuart Maconie, were enjoyable experiences.

The Codex highlighted the huge variations in sound quality from what are in most cases historic sounding recordings. For instance, listening to Joni Mitchel singing Clouds, recorded in 1971 reminded me what a beautiful voice she had. Likewise, hearing Ella Fitzgerald and and Oscar Peterson’s BBC TV recording of As Time Goes By, was pure magic, woven by two great artists. And yet these recording were definitely vintage, as were many of the Proms classical recordings. So, while the speakers are sensitive to programme material quality, and will reward listeners greatly when used with better sources, they don’t need the best demonstration material to be enjoyable.

That said, the most recent BBC classical proms recordings were quite magnificent – proving that BBC sound engineers are still as peerless at microphone placement and balancing live performances as they have ever been.

audio physic codex speaker review https://the-ear.net

I was so intrigued by the old Joni Mitchell TV performance that I searched Qobuz to find the 1971 BBC TV recording of Joni Mitchel and James Taylor at the Paris Theatre. The Codex re-created a full-bodied aural picture of her singing and playing acoustic guitar with Taylor, within the venue’s natural acoustics, and it took me back to 1971 when I originally heard it transmitted.

Quoting more examples seems almost superfluous, but I did play more music both streamed and from CDs of various genres: for instance, The Blues from Duke’s Big 4, featuring Duke Ellington in his later years, with big band (on JVC XR 0022-2). Ellington’s piano was reproduced convincingly, and with the whole band clearly laid out with excellent stereo. Contrasting musically, Daft Punk’s Give Life Back To Music and Get Lucky from Random Access Memories, proved an excellent test of the Codex’s bass performance. They filled the room with powerful, nicely timed bass, not just deep, but textured, which was felt as well as heard, and never boomy. Subjective bass speed and depth tend to be mutually exclusive, and so are rare bedfellows. Given the subterranean bass delivered, I reckon Audio Physic has struck just the right balance between the two.

Audio Physic Codex verdict

Summing up: from top to bottom, the Codex speakers are a tour-de-force of Audio Physic’s technical know-how. Quite apart from being fascinating from an engineering viewpoint, they are, more importantly, very good at making music.

They don’t fit into the ‘highly detailed’ or ‘analytical’ categories, but are full-bodied and curiously self-effacing. By that I mean they impose very little of their own character and therefore don’t get between the music and listener. They simply dissolve and delight, especially with acoustic recordings and vocals. Mid ange is fluid, treble is detailed, yet smooth, and bass is agile, well-timed, and powerful when required – delivering  surprises when seriously deep or impactful bass comes along. Quite magnificent; and yes, I shall be sad to see them go.


Type: reflex loaded 4-way floorstanding loudspeaker
Crossover frequencies: not specified
Drive units:
Bass: 250mm paper cone
Mid bass: 180mm aluminium cone with double surround
Midrange: 150mm aluminium cone
Tweeter: 39mm aluminium cone & soft dome
Nominal frequency response:  28 – 40,000 Hz
Nominal impedance: 4 Ohms
Sensitivity: 89dB
Connectors: single-wire binding posts (bi-wire optional)
Dimensions HxWxD: 1195 x 202 x 370mm
Weight: 38kg
Finishes: glass and high gloss wood veneer
Warranty: 10 years with registration

Price when tested:
Glass £14,295
High gloss £15,795
Manufacturer Details:

Audio Physic GmbH
T +49 2961 961 70


floorstanding loudspeakers


Dave Berriman

Distributor Details:

Cyrus Audio

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