Audio Physic Step Plus loudspeaker

In the 1990s, while putting together one of my early hi-fi systems, I'd often visit New York City audio retailer Sound by Singer to gawk at their top-tier wares. On one such visit I noticed a serious-looking gentleman listening to Stravinsky's The Rite of Spring through a pair of Audio Physic's Step loudspeakers (accompanying electronics long forgotten). Sitting on their dedicated, minimalist-looking metal stands, the pint-size Steps were angled up 22° or so, to create a physical time alignment of the tweeter's and midrange-woofer's wavefronts. The Step looked odd—kind of scrawny. But these petite minimonitors projected music that seemed to exist entirely free of their cabinets, pulling off a sort of "disappearing" act I'd never before heard.

Introduced in 1994, the original Step consisted of "a ¾" metal-dome tweeter and a tiny (4" plastic-cone) woofer with a chassis just 4" across—and a rear-firing port 1.25" in diameter," wrote Jack English in the October 1994 issue of Stereophile. That first Step was specified as having a sensitivity of 84dB, a nominal impedance of 5 ohms, and a minimum impedance of 3.3 ohms.

"The Steps' soundstaging presentation was consistent," wrote Jack: "excellent width and depth, pinpoint placement, and loads of spaciousness. For virtually any musical performance, I felt as if I was sitting at least mid-hall. Performers were never sitting out in the room or on the plane of the speakers. Rather, they were well behind and around the back. In addition, unless recorded as such, the music was never located in the cabinets. While many people may dislike the Steps' distant presentation, I found it quite enjoyable."

Not long after I'd heard the Steps at Sound by Singer, a pair of Audio Physic's floorstanding Virgo speakers became one of my proudest purchases. On each Virgo's narrow, 6.5"-wide baffle were a ¾" aluminum-dome tweeter and a 4" treated paper-cone midrange drive-unit, and on each side panel was one of two 6" woofers. They made glorious music in my small apartment. The slender baffle made possible these speakers' exceptional imaging, and those side-firing woofers gave me the lowdown goosebumps. Even if the Virgo's midrange was congested, and it didn't offer the last degree of dynamics or resolution, it was an easy speaker to love.

A pair of DeVore Fidelity's similar The Nines (narrow baffle, side-firing woofer) took up residence in my home in the mid-2000s, followed by their Orangutan O/93s. But I've always fondly remembered those original Audio Physic Steps. So when John Atkinson suggested I review that model's latest iteration, the Step Plus, I got (anticipatory) lowdown goosebumps all over again.

Standing 12.6" high by 6.9" wide by 9.8" deep and weighing 12.1 lb, the Audio Physic Step Plus ($2599/pair) has elegantly curved and tapered side panels that replace the original model's boxier look. The front of the Step Plus's cabinet is slightly wider than its rear panel, though its MDF walls are uniformly ¼" thick. Whereas the straight-sided Step was designed to be held at an angle, the Step Plus's rearward tilt—the angle is unspecified—is built into the cabinet itself. I imagine the design is both cosmetic and functional, lovely to look at while breaking up the cabinet's internal standing waves and aligning the drivers for optimal time arrival/phase coherence at the listening seat; I put this to Roy Feldstein, chief technology officer of VANA Ltd., Audio Physic's US distributor, who replied via e-mail, "The purpose of the slope was to add stability to the cabinet and create a more attractive form factor."


The Step Plus's drivers are the ones used throughout the Audio Physic range: a 1.75" (45mm) tweeter and a 5.9" (150mm) midrange-woofer, both with Hyper-Holographic cones of ceramic-coated aluminum (HHCM-III in the tweeter, HHCM-II in the mid-woofer). These custom-built drivers are made in China by Wavecor, Ltd. Manfred Diestertich, Audio Physic's R&D manager, is involved in every phase of these drivers' development, including the Step Plus's ClarityCap capacitors and its Dual Basket Design—basically two baskets in one, claimed to reduce unwanted mid-woofer resonances. Other Diestertich-enriched Audio Physic technologies include Active Cone Damping (a rubber ring around a driver's circumference) and CCAC ceramic coating of aluminum driver diaphragms to prevent "partial oscillations" ("ceramic coating increases the stiffness of the cones therefore the natural modes of the cones are moved higher in frequency," Feldstein wrote).

New to me was the use, in the Step Plus's midrange-woofer, of a flat-faced aluminum phase plug mounted directly on the driver's magnet motor. "The phase plug is made of solid aluminum and acts as a heatsink for the neodymium magnet," according to Diestertich. "The response curve is optimized off axis—as a result the phase plug was designed flat."

The Step Plus's drivers aren't mounted directly on its cabinet. The cabinet's drill holes contain neoprene plugs that tighten when screws are fitted, creating an elastic connection between drivers and cabinet that reportedly further damps resonances. Per Diestertich, Audio Physic also uses "ceramic (open cell) foam which acts as a brace to strengthen the cabinet, and as a diffusor (with a large surface area) to control resonances and standing waves." This silicon-carbide foam, used for filtering molten iron in the aircraft and power industries, looks like a dense gray sponge, and reportedly strengthens the cabinet and thus reduces its tendency to resonate.

The Step Plus's tweeter and midrange drivers, crossed over to each other at 2.8kHz, are mounted close together on its 6.9"-wide baffle. A 1.75"-wide port opens 0.5" below two sturdy WBT NextGen binding posts (the manual calls these "modern connecting terminal[s]") on the rear panel.

Audio Physic's website specifies the Step Plus's frequency range as 50Hz–40kHz. With a specified sensitivity of 87dB at 8 ohms impedance (6.5 ohms minimum), the little Step Pluses played comfortably loud in my smallish listening room at any wattage, assuming I was using the appropriate amplifier (see below).

Setup and System
Finding the optimal positions for the Step Pluses was, generally speaking, a breeze. Placing the speakers too close to the front wall diluted their fine imaging qualities, so no dice. Eventually, what proved ideal placements were with the speakers' rear panels 26" from the wall and their front baffles 65" from my listening seat. I toed them in until their inner side panels were barely visible. And though I'd first placed the speakers in more or less the same spots as my go-to DeVore O/93 Orangutans, moving the Step Pluses a bit farther apart than that—91" between their outer sidewalls—increased their already fantastic soundstaging. That didn't work with every recording, but when it did, the Step Pluses created a very wide soundstage with large, precise images.

Audio Physic GmbH
US distributor: VANA Ltd.
2845 Middle Country Road
Lake Grove, NY 11755
(631) 246-4412

tonykaz's picture

are the foundation of the Audiophile existence because of their superb Driver technology, design and build quality.

A nice representative Small European Loudspeaker will cost out around $2,500. Even the phenomenal Genelec 8020 Active Loudspeakers, made in Europe, will cost under $2,500!

But Audio Physic pretends to be German while sourcing in China.

Too bad for the replacement driver assurance program.

Yet another disappointment.

Tony in Michigan

Bertie Bucket's picture

Their speakers come with a 10 year warranty so that should give any normal buyer peace of mind.

Those who have hangups about Asians need not apply.

tonykaz's picture

.... Peace of Mind, it's sell-out worrisome.

Especially since Europe already is the Loudspeaker Driver Highest Authority.

It would be understandable if a Cayln built loudspeakers with DynAudio Drivers, that would be logical, not the other way around.

For this Decade and probably the next Decade, I will be discouraging the "Asian" Out-Soucring Concept among Manufacturing that I have influence in, the Transportation Industry.

HighEnd Audio becomes Low End throwaway mid-fi when it goes Asian. ( for now ).

Cayin is the exception, as is Woo which is USA Based and not at all Chinese.

Tony in Michigan

georgehifi's picture

All Audio Physic's even going way back when they started that I've heard, do this disappearing act really well, whether stand or floor mount. What is the measurement or construction parameter that is important that makes this happen. Seems like Audio Physic has whatever it is nailed down.

Cheers George

ok's picture

..Audio Physic (mostly Step and Tempo 25/Plus) iterations of this particular midrange/tweeter/cabinet configuration over the years and I can subjectively confirm JA’s prediction that their top surface should see slightly below the listener’s ears for optimal HF performance. This peculiarity is mainly due to a somewhat upward-shooting tweeter combined with a deliberately poor off-axis response (no more than 30 degrees flat thanks to cone driver and steep foam ring) that is further highlighted by the grills which tend to create some 3db drop at about 8KHz. They are excellent for near field and almost immune to HF room reflections for far field auditioning; however they do need considerable rear estate for enhanced soundstage accuracy and deep bass response as KM has already pointed out. By the way woofer's aluminum phase plug can dissipate an awfully lot of heat in case of amplifier clipping (not recommended!) so no worries about chinese: my neighbours would dismayingly attest that these drivers are virtually indestructible :-}

Bogolu Haranath's picture

Elac Navis active, self-powered bookshelf speakers ($2,000/pair) were very favorably reviewed in the latest issue of TAS ....... They don't need a power-amp ....... The reviewer said that, he would recommend them for product of the year award :-) .........

doak's picture

Haven’t heard these speakers, but really want to... and possibly own a pair.
Thanks for the heads up on the TAS review.

Bogolu Haranath's picture

In the on-line Audiogon discussion forum, one of the commentators says he compared the sound of the Elac Navis bookshelf with the sound of KEF LS-50 wireless and, he preferred the sound of Navis bookshelf (both models are active self-powered speakers) :-) .........

AaronGarrett's picture

The Audio Physic/ Pass Aleph combo at Singer in 1996 made me an audiophile! EDIT (Actually I misremembered -- it was Stereo Exchange. I am now an old audiophile with a faulty memory!)

Bogolu Haranath's picture

Welcome to the 'audiophiles with faulty memory' club :-) ..........

jimtavegia's picture

I would expect better performance in terms of pure value. Andrew Jones and many others do a great job for under a grand. In the right room these might float someone's boat.

I don't mean to be critical, but at this price there must be excellent performance.

jbreezy5's picture

Spot on, Jim!

mumulaha's picture

I knew the measurement have it's flaw before purchase. But after I heard it in my room with correct placement, I am sold. 6moon's Srajan Ebaen bought Audio Physic Codex as his new reference speaker. I used to own Triangle Titus with same electronic.

Jason P Jackson's picture

Wavecor are a large, well known loudspeaker driver manufacturer with many of it's designs done by the engineers of another large, well known loudspeaker driver manufacturer.

Jason. P. Jackson

SpeakerScott's picture

Mr. Atkinson,

Would you ever consider adding baffle step correction to your nearfield measurements...or at the very least measure speakers using the ground plane method to eliminate this measurement error?

I understand that taking some of the massive mega-buck speakers to a parking lot or tennis court isn't possible, but there are several ways to mostly eliminate the emphasis shown in the measurements with modified technique.


John Atkinson's picture
SpeakerScott wrote:
Would you ever consider adding baffle step correction to your nearfield measurements...or at the very least measure speakers using the ground plane method to eliminate this measurement error?

Some other reviewers have done this, but the "correction" is arbitrary, given that every room will modify the "bass bump" to a different extent.

There are 2 ways of assessing a speaker's low-frequency output: 1) in an anechoic chamber, which represnts one extreme, and 2) using a nearfield measurement, which represents the other extreme. As using a true anechoic chamber is financially out of reach for an organization of Stereophile's size, I prefer to stick with the other extreme. This also has the advantage of being consistent for the past 30 years of speaker measurements published in Stereophile

The problem with ground-plane measurements is that you need a relatively large flat paved area in which to perform them, which is problematic given where I live. I have experimented, but ended up sticking with how I currently perform low-frequency speaker measurements, in the nearfield.

John Atkinson
Editor, Stereophile

SpeakerScott's picture

An anechoic chamber is well out of reach for me to! (Plus ones that get that low in frequency are rare.) I could only dream of having one, which is why I suggested the baffle step correction method. As you well know, when you measure nearfield you eliminate the reinforcement (or lack thereof depending on frequency) as the driver transitions from 4pi to 2pi space.

The process, if done correctly isn't arbitrary. I have compared the results for large towers, book shelves and even large pro-sound PA speakers to measurements I have taken using tennis courts or parking lots. In the case of the ground plane measurements I have actually taken the time to reverse the double height baffle step from the mirror image speaker and the results have been spectacularly accurate.

You could plot the more accurate method along with the old method for comparison It only takes a few minutes to do, it doesn't add significantly to the process of your entire measurement set but improves accuracy.

(I do know how long a full measurement set takes to make...I've done it more times than I can count.)

MiklD's picture

I auditioned Step 25 (the previous iteration without the ceramic foam and sundry tweaks) and was similarly impressed. Took home Sitara 25 (floorstanding 2.5-way version with an additional HHCM providing sub-500 Hz reinforcement) which provides a good half-octave of bass extension, while maintaining the sonic virtues of the bookshelf sibling. So this review provides some gratifying insight.

Interesting to see the wrinkles in the measured performance. Hard to put floorstanders on shorter stands though, maybe a raised platform for the listening chairs, and/or some DSP? I suppose to incorporate soundstage in the more objective realm some sort of standardised routine around one of those Chesky clap and footstep test recordings could be employed? That aside the range of individualised timbres delivered from diffent instruments (real and synthetic) is a complementary element to the legendary spatial qualities and ‘disappearing act’ and just as impressive.

I started the Sitaras with my venerable Krell KAV-300i and was very happy. I described the baby Krell’s untimely end in a comment pleading for Herb’s promised Micromega M-100 review (cat awoke from Class A/B warmed torpor and threw up into the venilation slots, no more input boards from Krell for that model, alas, and shameless pitch for Sydney’s Len Wallis Audio who tried valiently to find parts). A loaner Musical Fidelity M3i wasn’t bad at all, but I settled on the Micromega for more modern features and design and nice sound. Too nice though (soundstage didn’t quite open up and the bass lacked weight/authority/timbral richness and yes that may not be a real word) but remedied for now by running the M-100’s balanced pre-ouput to a Krell KAV-2250 from Ebay. Cobbling together satisfying sound on a tight budget has its moments, I guess (bid unseccessfuly for an Evo, them’s the breaks). With the right amp, the bass sounds deeper than it measures, so I’m not too surprised by Ken’s observations.

So no, as most readers here surely know (but not all commenters, it seems) speakers don‘t sound the same, amps don’t sound the same, and viva la difference (or the German equivalent for the Audio Physics).

Thanks also for the Irrisari, a nice discovery.

MiklD's picture

... and imaging. Looking at the Step’s cumulative spectral decay plot, it is unusually clean and fast to decay below 10 kHz even compared to a range of very good-sounding offerings reviewed here. Everything is pretty much done and dusted within a millisecond, while others take 2-3 times that. Wondering if this characteristic is a key reason for the soundstage, imaging and timbre differentiation I can also hear in the similar Sitara?