ATD Pata Acustica (Auditorium 23)

Music is a multi-dimensional event, and its re-creation through loudspeakers is understood to be an approximation at best. The most obvious dimension is ‘volume’, and the vast majority of listeners will be able to point out the difference in impression created by sounds played at low or high volume. The juxtaposition of silent and loud opens a space in which a listener’s associations range from soft and friendly to powerful and threatening. Human hearing is usually most comfortable when listening to music at volume levels ranging from 50dB to 80dB.

The second dimension is ‘frequency’. Most people will be able to tell the difference between a lower and a higher frequency sound. This is especially true, if the sound created is between 500Hz and 3,000Hz, where our our hearing is most sensitive. The space that is made available via the frequency spectrum offers a vast playing field to musicians and their instruments, ranging from ultra-low bass to the highest notes of the piccolo flute. Lots of engineering has been done in extending the linear frequency range of loudspeakers in an effort to capture the aspects of natural instruments and beyond.

A third dimension is timing. It describes the ability of a music source to emit its sound waves in a synchronous manner in order to capture the speed and rhythm of an original event. Accurate timing will be supported or hindered by the placement of the music source in the room. The overlapping of music frequencies bouncing back from walls and ceiling can usually best be eliminated by the listener's brain when there is sufficient time-lag between direct and reflecting waves. Loudspeaker manufacturers have developed different solutions to address the issue of timing. Tannoy and KEF, for example, have adopted coaxial designs, whereas others have pursued single driver concepts, such as electrostatic and magnetostatic diaphragms.

And, listening to the Pata Acustica, I was reminded of a fourth dimension, one that is often forgotten in comparisons between loudspeakers, especially in a country like Germany where my fellow listeners habitually rely on facts and figures and are often deeply sceptical when it comes to trusting their emotions: I am referring to tone and timbre. That is to say, the ability of a loudspeaker to stay true to the tonal colour of the physical material of an instrument. This quality is especially important when listening to Classical Music, Jazz, Folk, etc., in which the simultaneous presence of many instruments requires a space in which each can be recognised by its own individual character.

To musicians, instruments are often as recognisable as the voices of friends and lovers. They will discern and often prefer one manufacturer over another, solely on the basis of how the instrument makes them feel when playing and listening to it. Loudspeakers that are able to maintain some of this difference in character are thereby capable of opening a huge (and additional) space in which a multitude of instruments and voices can be separated by their specific tonal character. And, most likely, it was this tonal correctness that set the Pata Acustica apart from many other loudspeakers in its class and aroused the interest of the people at Auditorium 23 in promoting it to their audiophile disciples.

During the 90s, Auditorium 23 was approximately ten years into business. Its founders believed in the sonic integrity of single-ended tube amps and simple Class A designs that would feed their sweet and soft signals into horns for amplification. The Pata Acustica was obviously not a horn and as such an exception in their lineup of exquisit loudspeakers. Retailing at just under 4,000 DM, it was considerably cheaper than folded horn designs, and it was also smaller than most of the other speakers. Manufactured by ATD in Italy and rated 91dB at 1 watt, the Pata Acustica played both loud and tonally correct on smaller tube amps. And this made it a real gem in the Auditorium's special circle of listeners.

When it first came into our house for auditioning, I knew close to nothing about the Pata Acustica. As usual, I prefer to conduct my listening assessment before digging deeply into the subject, simply because I do not want to bias my exploration towards a certain result. All I had heard from Luigi was that it performed well on tube amps. If I had any bias, it was that I feared the smallish speakers would sound hopelessly lost in our spacious listening rooms. I dug out our two stands that we had constructed for the KEF iQ30s, dusted them off, and mounted them on spikes towards the hard-wood floor. I then stuck 5mm felt pads to the four corners of the stand tops and placed the Patas on them. In my previous explorations, felt pads had always proved beneficial in taking the edge off a cold electronic top-end.

Our test system was made up of a Technics SL1310 turntable with AT VM540 ML cartridge hooked up to a Dynaco PAS-4 tube preamplifier that was feeding into a Hafler XL280 power amplifier. All interconnects were made of solid-core silver, such as the HBS4, with copper mesh shielding. The speaker wires used were a pair of Belden 9497 that I had terminated with beryllium hollow bananas. At the time of listening, all connectors had been sufficiently run in to reach sonic maturity and proven themselves over the course of many months. I was familiar with this system performing with our relatively modern Tannoy XT8F tower speakers.

Switching to the Pata Acustica, I noticed that I had to dial back the volume a little. This was surprising to me, as I would have expected the larger Tannoys to play louder. I later checked and found that both speakers were rated the same 91dB at 8 Ohms. My only explanation for the Patas playing louder was that they did not extend as deeply as the Tannoys, thereby losing less energy on the fringe of the audible spectrum. And this brings me to my second immediate observation: the lack of bass extension. Since the Pata’s woofers were built into the closed cabinet of a bookshelf-size loudspeaker, they quite understandably could not compete in the discipline of bass with a ported down-firing floor-stander of nearly tripple their size. Strangely enough, this lack was only apparent on first comparison, because, soon after, other aspects gained greater importance.

Instead of the ultra-low growling of bass extension, the Patas produced the dry snarling so familiar of some wooden instruments. The result was a more grainy and wooden texture that was predestined for Classical Music, Jazz, and Folk. Katie Melua's “Album No. 8” was presented with a wonderfully large and solid phantom centre. Her voice was lush with only the slightest hint of the recording’s original metallic ringing. While the highs were not overly detailed, they were wonderfully nuanced with great timbre. It was the most enjoyable rendition of this particular album that I had heard until that point. There was great channel separation with the stage extending wide across the room. Stage depth, on the other hand, was less impressive. It suffered from the need to place the speakers close to the wall. This need can be a blessing and a course. However, I decided not to mind and rather marvelled at the warm wooden tones of concert guitar and piano. The Patas managed to highlight the sweetness inherent in the music, perhaps slightly thickened with an small and endearing mid-bass hump.

I decided to step it up a bit and put on Ted Poor’s “You already know”. The saxophone never sounded so sweet to my ears. Drums, especially kettle drums, were presented with great realism regarding their respective material composition. I noticed superb transients and great separation between tonal colours of each instrument. If I were to describe the effect, it would be: “total immersion in the music”. While there were moments in which the Pata Acustica’s small dimensions became apparent, I found myself genuinely perplexed by what these loudspeakers were capable of. I especially enjoyed the fact that I could listen to them and, while doing so, completely forget that I was listening. Walking across the room, I was pleased to find that much of the Pata's musical attraction remained. Well done!

Also see: ATD Pata Acoustica (Auditorium 23, 1995) Audio Demo

Specifications:

• Design: 2-way bookshelf, closed cabinet
• Drivers: (1x) 20 mm soft-dome tweeter, (1x) 200 mm paper cone
• Nominal impedance: 8 ohms
• Sensitivity: 91 dB
• Power handling: 6-60 watts RMS
• Terminal: originally Speakon (here: modified to banana sockets)
• Dimensions: (H) 470 mm x (W) 270 mm x (D) 250 mm
• Year: 1995

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