oudspeaker is a sophisticated electromechanical system in itself that additionally works in conjunction with the room. It is true that for a hundred years the main principle it is based on has not changed much. Even the introduction of radical new concepts, such as Distributed Mode Loudspeaker (DML), developed by NXT, did not bring a breakthrough as if the status quo was unbreakable. The basic elements are still: a cabinet, transducers and crossover. There are some variants such as electro- and magnetostatic speakers, but they are only an addition to the mainstream offer.

Designers operate using some forms of these three elements by selecting specific transducers, placing them in a specific cabinet using a specific crossover. Sometimes one more element is added to this contact equation – a particular placement of the speakers in a room. The Audio Physic, a German manufacturer whose Tempo Plus loudspeakers are reviewed in this text, has its own original recipe for that. It offers speakers with extremely narrow, leaning back front baffles that they also suggest to place in a room in a special way.

The general rules for setting speakers in a room have been known for years. These should form an isosceles triangle, with speakers placed at the ends of the long shoulders and a listener on the vertex formed by them. Discrepancies arise when we ask the manufacturers about how the loudspeakers should be toed-in, i.e. where their radiation axes should cross. The answers could roughly be divided into three groups: a setting with a slight toe-in (or straight forward), with axes crossing at the listening position or with a significant toe-in, i.e. with axes crossing 0.5-1 m in front of the listening spot.

Anyone can try out each of these settings at home. However, when one asks some manufacturer for a recommendation, one shall usually hear something like: "in our opinion," because the speakers are measured individually, most commonly in the an-echoic chamber. And yet, the way a couple of them actually behaves depends on a room they are in. Audio Physic has, however, developed its own setting. It stems from design assumptions, which are about the best phase alignment of individual drivers. The loudspeakers of this brand should be set up as wide as possible and pointing directly on the listening spot. This results in an incredibly wide, stable, filled in sound stage that most other manufacturers can dream about.

Tempo Plus

To achieve this, Audio Physic has developed its own set of techniques/solutions. The Tempo Plus benefit from developments have been introduced over the years for subsequent versions of Tempo - the "Plus" version is the ninth one! They feature a very narrow front baffle, with only tweeter and midrange drivers, while the woofers are screwed on two side walls. All of them are decoupled from the cabinet by means of neoprene washers and a kind of "suspension" - the fastening screws are not tightened directly to the baskets and cabinet but rather through neoprene, resilient bushes. Flat bars stabilizing the entire structure from the bottom are also decoupled. The front baffle is tilted back, which ensures phase coherence between the two drivers.

The bass woofers are made for Audio Physic by Tymphany. They feature aluminum diaphragms and extruded metal baskets. Much more interesting are the drivers mounted onto the front baffle. The HHCT III (Hyper-Holographic Cone Tweeter III), a new generation tweeter known from earlier versions of the AP loudspeakers, was used here. It is currently used also for much more expensive Avanti and Codex models. It features a hybrid membrane combining a silk dome and an aluminum cone.

Even more interesting is the midrange driver, HHCM II (Hyper-Holographic Cone Midrange Driver II). Like a tweeter it is also custom-made for the AP. Its diaphragm is made of aluminum that is coated with ceramic sinter (a similar solution to the one use by Monitor Audio). The basket features two parts - the exterior of cast aluminum and the inside of a very rigid plastic. They are designed to provide stiffness and proper damping. The diaphragm is driven by twin neodymium magnets enclosed in the heat-sink. In the middle of the diaphragm, where the dust cup is usually located, there is a large aluminum phase plug.

The aluminum diaphragms' inherent feature are high-amplitude parasitic resonances outside their frequency range. To prevent this, manufacturers use high-order high-slope crossovers. However, these have their own problems. Audio Physic uses low-order crossovers, so it dampens these vibrations by sticking a silicon rubber seal on the bottom of the diaphragm. This solution is called Active Cone Damping (ACD).

The loudspeakers feature an attractive aesthetics and fit nicely into a room. Tilted baffles make their design look dynamic. The cabinets stand on aluminum, black-painted flat bars with spike screwed in them from the top. These can be conveniently adjusted from the top using large handy nuts. The set comes with a small level and a certificate with the serial number and signatures of people responsible for each stage of production.

The Audio Physic Tempo's (and all their subsequent incarnations) main goal was to offer the best possible imaging. I can clearly recall the premieres, shows and presentations of this company I participated - in all of them this aspect of sound reproduction was particularly emphasized. So now we know what to look for, and being rational people we are also aware that this sonic feature has to come at some cost - in (audiophile's) life nothing comes for nothing. So I knew it would be interesting not only to find out what these loudspeakers do really well, but how they deal with the "cost", something designers had to sacrifice to achieve their primary goal.

They are quite special in imaging, that much is obvious. This aspect of music reproduction is often referred to as "building a sound stage", "rendering phantom images", etc. These are good terms that are firmly rooted in our industry's vocabulary, with appropriate connotations. It seems, however, that 'imaging' is a broader term, and thus better describing the whole phenomenon that we understand under the term 'stereo'.

It does not mean quite the same though. Tempo Plus prove in a fantastic way that imaging is also applicable to monaural recordings. These loudspeakers build clear, distinct bodies, almost the very "instruments" themselves either in the panorama in front of us (stereo), around us (stereo with surround information) or straight ahead of us (mono). This last category is interesting because Audio Physics seem very precise and clean. They also deliver a particularly clear, crisp sound that helps listener to differentiate positions of the instruments as well as a well-marked attack phase, which in turn guarantees a high subjective dynamics.

Instruments are, in a word, in a similar fashion to that of a live event. The space is huge and well organized. There are more loudspeaker models that can "throw" a huge panorama in front of a listener, but almost always it seems like an artificial operation, and the sound stage is not just "big" but rather "blown up". The effect seems to be the same, but its reception is completely different. With Tempo Plus it sounds believably, naturally.

With them some recordings in which the way of constructing the "presented world" doesn't always work, gain meaning, and one can finally hear what the people responsible for these recordings wanted to achieve with them. A good example is the latest Livingstone Taylor's album, released by Chesky Records. The material on it was registered with a binaural artificial head, and the signal was then converted so that it could also be listened to using speakers (this Chesky series is called Binaural +).

Even with Harbeth M40.1, offering perfect imaging, this album seemed to lack some details, it sounded unconvincingly. The space was obviously spectacular, but – let me repeat - unconvincing. The German speakers, however, showed me that there are minor changes in intensity, phase, yielding an abundance of information, richness of the sound, which are obvious when listening using headphones, but not so unambiguous when delivered by loudspeakers, despite the "adaptive" algorithm used for this recording. With Audio Physics this recording made a lot more sense and it finally was convincing.

I cited an extreme case but also with mono recordings the ability to create a believable presentation was extraordinary. Sinatra from the 1947 recording, I mean the mono and stereo tracks remastered for SACD releases collected by Stereo Sound magazine on the double album A Day at Jazz Spot 'Basie'. Selected by Shoji "Swifty" Sugawara, classic stereo productions such as Niels Thybo, Bo Stief, Lennart Gruvstedt's Super Trio and Jim Hall Trio & Tom Harrell's These Rooms, up to rock climates by Laurie Anderson and Peter Gabriel recorded using multi-mono (multi-track) techniques – with each of them I was offered a fantastic spacial presentation, ie instruments with accompanying acoustics.

It was not about cutting images out of background because it would be idiotic, but a natural "blending" of the event being played back with the listening room it happened in. The space was large, expansive and very accurate. I don't really remember many times with any speakers when the information out-of-phase, both recorded in a special system (eg QSound) and generated for a particular recording (eg Homeland) was so robust, accurate and fleshy as during this listening session.

The latter, ie fleshiness, combined with precise imaging was - at least for me – a novelty. It is so because the characteristics I mentioned was achieved by, on one hand precise material and design engineering, and on the other by reducing richness of the midrange and bass. It's pretty easy to simulate precision by filtering out some of the information that is difficult to reproduce. The early Tempo models that I listened to used this method to some extent. Thanks to the proficiency of the designers, these issues were not particularly annoying, but they were always there, somewhere below the surface.

Tempo Plus are different. They also have not so rich midrange within the range of - roughly - 600-800 Hz. For the first time though, this decrease of richness did not affect the whole band. The reason for that was a strong bass with a nice, soft character. There is also fleshiness, and richness, and density. These inconspicuous speakers can fill even a large room with a very natural sound. And there is not much difference between albums with “enhanced” spacial effects or mono ones, jazz or rock – each time a presentation was equally convincing and highly enjoyable.

The might be a slightly bigger problem with the contemporary recordings featuring strong compression caused by stupidity or used for convenience (which means most modern pop and rock recordings) or for creative purposes (new Ed Sheeran's album) or used to create a special sound effects (John Foxx and the Belbury Circle, Empty Avenues). Compression equalizes dynamics, increases average sound level, but also hardens attack and decreases resolution. That is why mp3s listened using a resolving system sound in an irritating way, as if someone was pounding a sword with a sword.

The Audio Physic speakers do not emphasize this problem, they are not scanning through played material in order to find problems to punish the listener. So there is no destruction of the temporary illusion of listening to the real event. But there is a tendency in this direction. The powerful midrange around 1 kHz and above, accurate and open, is not compensated by enriching midrange, which, for example, with Harbeths allows me to enjoy almost every recording. To be clear: both Harbeths and Audio Physics modify the signal, they are not neutral, but Tempo Plus goes in the direction of disclosing problems, and Harbeths prefer to deliberately let them go by.

I think that avoiding the “neutrality at all costs” trap, that, at this price level, can not really work, was possible in case of these German loudspeakers because of a rich, dense bass. As in most cases with loudspeakers featuring side-firing bass woofers, bass it is not as “genetically” compatible, as coherent with the rest of the band as it is in high performance classic designs. But I had no problem with that, because it was a delicate indication, not a clear finger pointing.

All the more, there was a lot of bass, it was nicely differentiated, had a very nice timbre and a physiological, soft attack. I would call it a "feline" bass, i.e. with visible but hidden claws, with emphasis on soft cushions. I liked its differentiation because the speakers showed changes in positions of bass instrument, their timbre and dynamics, but without emphasizing these elements. The coherence with the rest of the band was very good, taking into consideration what I said earlier.

Some advice

Although the sensitivity of the tested speakers is quite high, one should pair them up with an amp with good current efficiency. In addition, it should be one with its own strong character. With neutral sounding amplifiers, ie those that do not add much to the presentation and even take something away, Tempo Plus could deliver a bland, featureless performance that I definitely wouldn't recommend. One could choose both, tube and solid state amplifiers. But, for example, Class D amplifiers (Jeff Rowland, SPEC (in Polish), Audiomatus) should be a better match than classic Class AB ones. One could also choose one of many tube or hybrid designs - generally these should be a warm sounding, powerful amp.

The German loudspeakers perform very well positioned 0.5 to 1 m from the back wall. The distance from side walls should be as big as possible. In the instruction manual one can find a drawing that suggest both these distances at 0.5 m, but I believe one should treat this numbers as minimum rather than target ones. It is important though that these two distances are different (i.e. the distance from the back and sides wall should not be equal). These designs perform well placed wide apart but close to listener, with their axes intersecting in front of the listening spot. Such a significant toeing-in most often narrows the sound stage. Audio Physics can be placed wide and seriously toed-in – such placement will deliver an incredibly precise and wide soundstage with a very strong center.

Summary

The Tempo Plus loudspeakers offer everything the Audio Physic products are valued for, but in a more sophisticated form than same money could buy a few years back. There is here huge, well-constructed space, there is also a nice richness to the sound and a strong, pleasant bass. The voices and instruments are big and incredibly concrete, powerful. These speakers are relatively small, but they feature a very good form, so they will complement any well-designed interior without drawing too much attention to them. A potential owner should considering pairing them up with an amplifier with character to achieve a high end performance for relatively reasonable price. And a soundstage that his audiophiles friends will secretly envy him.

The Tempo Plus by the German company Audio Physic is a three-way, four-driver floorstanding loudspeakers with vented cabinets. They offer a particular look - they feature a very narrow front wall but their depth is quite significant. The tilted front makes them optically almost disappear from the room. They are also very aesthetically done, with a natural veneer and grills with pins (I think the magnetic ones would be a better choice). The bass woofers grilles are fastened and should stay on during listening sessions.

Drivers

On the front side there two drivers installed – a tweeter and midrange woofer (custom-made for Audio Physics), plus there are two bass woofers placed on the side walls. The speakers feature a rear bass-reflex ports. The HHCT III tweeter (Hyper-Holographic Cone Tweeter III) is a hybrid design with a 25mm silk dome and an aluminum cone. The driver was decoupled from the cabinet using a special spacer.

The HHCM II midrange driver (Hyper-Holographic Cone Midrange Driver II) features an even more advanced design. Its diaphragm is made of aluminum covered with ceramics (as in Monitor Audio speakers). It is mounted on a double basket - cast and plastic which results in improved vibration damping. The driver is powered by a double neodymium magnets and features a large phase cone made of aluminum. To extinguish parasitic vibrations outside of the frequency range, a silicone rubber ring is attached to its diaphragm. This allowed the use of low-order filters in the crossovers. The solution in the company's literature is called Active Cone Damping (ACD).

The bass woofers work in phase, in the same chamber, radiating in two directions simultaneously. The bass-reflex port was placed exactly in the middle of rear panel. These are 170 mm Tymphany drivers with aluminum diaphragms and embossed steel baskets. They are driven by classic magnets. All drivers used in these loudspeakers are decoupled using rubber "spacers" pressed into the screw holes.

Cabinet

The cabinet is made of MDF. It is reinforced inside using numerous crosspieces and damped with two types of materials. One is classic, it's material similar to sheep wool, but closed in something like a bag. The second is more advanced – these are strategically placed open cell ceramic foam elements. The space between the pores is filled in in over 85% with air. The crossover was assembled on three separate boards, one for each section. The cabinet is tilted backwards - both the front and rear walls. Also the side walls are not parallel - they gently coincide towards the front.

The WBT speaker posts look very neat and convenient to use. These represent the nextGen series, which mean only a minimal metal content. They were bolted to a rigid, aluminum plate. In previous models the plate was bolted, here was pasted. It is damped using a neoprene spacer; The solution is called Vibration Control Terminal (VCT). Let's add that internal connections are made using a nice Audioquest cable.

The loudspeakers are stabilized with two thick aluminum bars, screwed to the bottom of the cabinet. Screws are screwed one through similar springs as ones used for drivers. The whole cabinet stands on steel spikes. They feature large, nice nuts from the top that allow user to easily adjust the speaker's level. Underneath the spikes protrude only a little. I did not find a set of washers in the box, so I applied mine - Acoustic Revive SPU-8. One could also try the Franc Audio Accessories Ceramic Disc Slim Foot for the same purpose.

Specifications (according to manufacturer)

Sensitivity: 89 dB
Frequency range: 32 – 40 000 Hz
Nominal impedance: 4 Ω
Recommended power amplifier: 20 – 150 W
Dimensions: 1000 x 187 x 320 mm
Required footprint (W x D): 290 x 430 mm
Weight: 20 kg/pc.