26
Jun
11

Avantgarde Uno Nano G2

The most formidable horns ever built!
Avantgarde Acoustic Uno NANO G2

In 1994, from a small 120 sq m garage in Walsdorf Germany, a new loudspeaker manufacturer is born. Showing their small range of product at the Frankfurt High End Show the same year with great success, this new company known as Avantgarde Acoustic, make some of the most visually arresting loudspeakers available. Their speakers encompass both the classic traditional horn loudspeakers with a modern interpretation – the large beautiful molded horn looks more like sculpture than speakers. Then the large horn can be had in a color of your choice, a good move as the WAF (Wife Acceptance Factor) grew immeasurably as a result.

From the very beginning Avantgarde Acoustic had a mission – to create a potent, authentic and utterly unique music experience. Avantgarde developed the spherical horn systems, which comes closest to realizing their objective. After 15 years when the first Avantgarde loudspeakers – the UNO, DUO and TRIO were first exhibited in Berlin, Holger Fromme and Matthias Ruff, the founders of Avantgarde now feel the evolution of the spherical horn design has reached a sufficient maturity in its development that the new products being developed is a significant upgrade from the first generation of horn speakers. Hence Avantgarde G2 – the second generation.

The power and effortlessness of horns.
Avantgarde Acoustic horn speakers are based on the physics of mother nature. They embrace the same principles that govern the functions of the human ear. The funnel shaped opening of the horn amplifies even the most minuscule deviations in sound pressure. A horn is the most natural and powerful way to amplify sound waves. At a given output, speakers with horns have an up to 95% lighter membrane. Driver over–excursion and the resulting distortion are avoided. In addition, for a given driver size, they have an up to 20–times higher acoustical output. As a result, the audio signature is livelier, as the membrane only has to execute a fraction of the movement.

A horn is the most sophisticated form of any loudspeaker: minimal mass and motion – maximum power – increased fidelity – reduced distortion. The combination of lightweight drive system and performance make Avantgarde Acoustic horn systems inimitable. The spherical horn speakers are faster, more dynamic and more coherent.

The first model in the G2 series is the entry model NANO G2 which replaces the original NANO. The original NANO sells for $22,000 a pair in standard finish; the NANO G2 ups the retail to $27,800. The difference pays for a lot of new parts, new upgrades and a redesign of some critical components. To say the speaker has been substantially revised is an understatement. A more apt description is a whole new speaker adhering to the original design precepts, with substantially improved construction, parts and design.

Intelligence.
Large drivers are required to reproduce low frequencies at higher volumes. Inevitably big membranes have a relatively large mass. The inertia of this mass weighs down the music signal, resulting in a thick, muddied sound.

The lower the sound pressure level, the more this inertia mutes details of the signal response. Big passive speaker systems thus invariably have, at low volumes, a heavily reduced bass articulation. To avoid these effects, all Avantgarde Acoustic systems are equipped with “intelligent” active subwoofer systems. The electronics detect output deviations of the driver from the input signal, and fast analog circuits compensate the cone movement. Due to the intelligence of the adaptive electronically control, the bass response of the speakers is cleaner, deeper and more dynamic – independent of room and output level. In addition, a variety of user controls allow the response to be fine–tuned and matched to the room acoustics.

Starting with the subwoofer module the SUB225-G2 which replaces the old SUB225-N – the drivers now comes with powerful Neodymium magnets. The amplifier is the same 250 watts design but now comes with a larger power transformer and more storage capacitance. This should increase the power reserve for short-term transients without running out of juice. I believe the amplifier is a servo design – Avantgarde calls it intelligent – an adaptive motional feedback circuitry keeps the amplifier and driver behaviour in check. The result is better control of the bass frequencies leading to faster, more transparent and more extended bass response with less room excitement.

Simplicity.
The crucial element in the development of any loudspeakers is to reduce the number of components to the minimum. Every single part in the signal path deteriorates fidelity, and colours the response. A principle element of Avantgarde Acoustic’s purist design philosophy is to reduce the number of components to only those, which are absolutely necessary.

Thus, all Avantgarde Acoustic speakers are designed with no passive filters in the signal path of the midrange horns. As such, the electrical signal from the amplifier is directly connected to the voice coil of the driver assembly. This Avantgarde Acoustic concept has an outstanding strength: simplicity!

Same driver, new horn
The G2 uses the same M1-N midrange drive unit, driven full range without any passive crossover components in the signal path. The horn however, is a new design – SH5003 for the G2 vs SH5002 in the earlier NANO. Likewise the H1-N tweeter is from the earlier NANO with a new horn design, the SH1301. The design of the horn would have an enormous effect on the sound quality otherwise Avantgarde wouldn’t have considered the new NANO the new generation.

Impedance.
Any speaker presents a specific electrical load – which is varying, depending on the music signal – to the amplifier. The more complex these (feedback) forces, the more the quality of the signal processing of the connected amplifier are suffering.

Accordingly the development of Avantgarde Acoustic horn systems does not stop at the speaker itself.

Avantgarde Acoustic rather sees the loudspeaker as part of the whole audio system. The optimization of the interaction of the individual components and the audio subsystems becomes part of the engineering discipline.

For this reason Avantgarde Acoustic engineering is exemplified in its sophisticated OMEGA driver technology. With OMEGA drivers, voice coils with very high impedance are utilized. The (feedback) forces induced into the amplifier are thus being effectively reduced. Avantgarde Acoustic horn speakers pose a substantially less critical load, are easy to drive, and bring out the true potential of any quality audio amplifier.

Improved architecture
One of the most significant change is the new frame. The original UNO NANO was derived from the original UNO, the uprights sort of hold the speaker together. The problem is torsional twist when the drivers are driven hard, the whole structure would tend to flex and colour the sound, reduce the bass impact and affect extension. The new NANO G2 now comes with a significantly improve rig: spike feet instead of discs, a rigid braced frame that reduces if not eliminates torsional flex altogether.

Listening
The old UNO NANO is Avantgarde’s most compact full range loudspeaker. This alone would be NANO UNO’s best selling point with the current trend towards smaller homes. The substantial changes imposed on the G2 are a necessity in the evolution of this species and the NANO G2 must significantly outperform the original NANO. This audition was done in the distributor’s showroom. Unfortunately, the original NANO has long been sold to make way for the G2. Coupled with the fact that the G2 had just arrived with less than 24 hours of playing time, makes it a moot point to compare it with its predecessor. What we can do however is to give an initial impression, as to not what the changes wrought but whether it does justice to music.

Room matching
First order of the day is the realization of the sound from this speaker is able to drive the room effortlessly. There are speakers that can move a lot of air within the room but much of it is wasted in exciting room resonances to the point you would need a lot of ‘room treatment’. In contrast, the NANO G2, which utilises the same woofer system as its bigger brother, the DUO G2, with dual ten-inch woofers, will certainly move a lot of air. One nice thing about the Avantgarde’s use of an active woofer system eliminates most placement problems – it allows you to tune the woofer system to suit. You tune the speaker’s midrange and tweeter for optimum mid to high response – getting the best sound in terms of openness and dispersion and then tune the subwoofer setting to match.

That said the NANO G2, like its bigger brothers, is a loudspeaker you need to sit a little distance away for the sound from the various drive units to integrate properly. As a rule of thumb, your listening position should be a little further than the distance between the left and right speaker. It is certainly not a ‘near field’ monitor.

Amplifier matching
You might think a big speaker like the NANO G2 would mean it needs a big and powerful amplifier. In fact, it is the opposite. Avantgarde speakers are designed to make the most of every watt of amplifier power and yet offer an identical sense of scale to a live performance. As the bass region from 300 Hz down is taken care of by the active woofer system, the amplifier only needs to drive the midrange and tweeter horn. Ten watts is the recommended power rating. You can choose from 300B SETs to EL84’s or anything that you fancy. This is one speaker where the rules can be broken, there is nothing that says you cannot run a simple tube integrated and a simple CD player that together would sell for much less than the asking price of the NANO G2 – and get excellent performance. I dare say this $27,800 speaker might just fit a system costing not significantly more than $30,000 (give or take a couple of clams) including a decent pair of interconnect (you need two, the second one for the active subwoofer)and speaker cables! Speaking of speaker cables, Avantgarde do not subscribe to bi-wiring, so please stop asking.

The speaker is tested in a large room, Avantgarde recommended room size suggest anything from 16 sq m upwards which means a fairly small living room – say 3m x 5m and larger would work. Seated about 5 metres from the speaker, driven with a 211 SET amplifier, I settled for a simple jazz recording – S.M.V. which has one of my favourite bass players – Stanley Clarke. My first impression of the NANO G2 is its proper balance in terms of scale – the relative perspective of the musical instruments size and relative distance is excellent in my book. Each instrument has a sense of space and air around it, not exaggerated or hyped up, it defines the space where sound expands exponentially from the body of the instrument.

It struck me every time I listen to a horn speaker, there is always a sense of that typical horn ‘honk’. It is just a matter of the degree this colouration manifest itself. The earlier generation of Avantgarde, in my opinion, do have a small degree of this colouration but by any standards, is already quite mild in comparison. In the G2, this horn colouration has effectively been exorcised, at least significantly to the point that you wouldn’t realize you are listening to a horn speaker when listening blindfolded. I wager that the NANO G2 is about one of the least coloured speaker in its price range, and we are not just talking about horn speakers.

Devoid of colouration, I found I could explore the architectural presentation with ease. It was then I discovered the NANO G2’s presentation of micro dynamics is pretty awesome. These two attributes together is responsible for the sense of dimensionality of this speaker can convey for this particular recording. I can almost imagine if you would bring this speaker home, you would spend days if not weeks rediscovering all your favourite recordings in a way your former speaker will not be able to. That, I think is all the G2 needs to convince me that we have something pretty extraordinary here. And for that, Mr Holger Fromme had indeed delivered what he promised – a whole new generation of Avantgarde speakers that transcends all that has come before.

Technical Specifications:

104 dB sensitivity
8 Ω drivers
20-inch spherical midrange horn
CDC system with no crossover
Bass with active feedback control
2 x 10 inch neodymium bass drivers
250-watt subwoofer amplifier with 60.000 μF

Article contributed by Terence Wong of MOD AV magazine.

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