STEREO 09.2007

Back in the box!

Sound-impairing resonance from component housing vibration is designed to vanish in the new "Resonator" from finite elemente. STEREO tested the new miracle box

by Matthias Böde

Opening Pandora's Box has often been compared to opening a can of worms. In contrast the Resonator box from finite elemente is designed to eliminate a lot of the vibration that interferes with our listening enjoyment. This sounds plausible, given that we regard the German rack and component feet specialist as one of the most competent and experienced companies on this planet when it comes to the dissipation and elimination of component vibration. I mean, in our listening rooms their racks quite literally form the basis for many of our tests, and time and again other products from this manufacturer have proved their value.

The new Resonator is no exception. The 28 millimetre high and twelve centimetre in diameter aluminum case contains a star-shaped element of stainless steel that takes up oscillation energy from the surface of the components and converts this internally into kinetic and thermal energy.
"With our racks and component feet we have the resonance problems at the components' bottom plate under control. And the Resonator now deals with this on the top." Bernd Brockhoff, finite elemente. On the underside of this device, developed in cooperation with Dortmund University of Applied Sciences, there is the 3.5 centimetre circular contact surface made of stainless steel. Simply place the disc on a pre-amp, CD player or other component, and it takes up the energy that would otherwise negatively influence the reproduction in the form of a resonance loop into its star-shaped innards where it is eliminated. So it really does what feet and racks do on the underside of the components, namely it dissipates and converts the kinetic energy resulting both from the noise energy and also from the transformer and other parts of the components.

"This effect is based on the energy minimum principle" explains a Dortmund University dossier, "whereby with two excited elastic structures with different masses arranged in series the system with the smaller mass takes over the kinetic energy of the system with the greater mass and converts this into heat assuming that the intrinsic frequency of the smaller system" is tuned to its excitation frequency. So much for the physical principles.

To achieve as wide a use as possible the Resonator was set for broad band applications, specifically covering that range where the human ear reacts with particular sensitivity to interference and changes. This is in the 500 Hertz range, which is why the Resonator, which is completely decoupled from its aluminum casing using microcellular rubber, was designed for maximum effect here.

This is the reason why finite elemente recommends that the Resonator is placed towards the component edge rather than simply in the centre. The blue areas in the schematic drawing below right mark the regions with the best effect. In the centre area the material often resonates at too low frequencies according to the company and the University of Dortmund so that the Resonator is not optimally excited.

In practice you will need to experiment a bit until you find the optimum position for the resonance trap on your own equipment. As our tests showed this depends essentially on the design of the component, for example the location of its transformer. It's fun to do and not too difficult, as you will immediately notice clear differences.

We set the standard high from the outset and tried the resonance trap on the Nagra PL-P preamp. This is a tough task as this compact amp does not have a humming transformer in its housing and, additionally, it is a very solid assembly. But even here the resonator worked wonders. Placed close to the top left corner, so above the input tubes, it provided clearly increased transparency, liveliness and opened up the spectrum. The spacings between the musicians seemed to be much more differentiated, and generally the bass relief became much more three-dimensional and the sound image was staggered without any effort to the top and both liveliness and flow increased dramatically. At the same time the bass increased in dryness and contour.

We hadn't expected this, especially since this 11,000 Euro preamp was already standing on finite elemente Cerapucs, fitted with only the best cables and the tube pins had all been treated with "ProGold", all of which had already clearly improved the sound. What else can you do for around 500 Euros? Well, for example, use the Resonator that deserves a place of honour on the PL-P.

But this was only the beginning of the success story of the smart-looking disc. Placed at the rear of a Lua 4545c standing in a completely different constellation, the result was very similar. Again we had the improved depiction, there was more light and airiness in the representation and a sort of springy noblesse came to the fore that the amplifier on its own had not developed to this degree. As already experienced on the Nagra the Resonator caused improvements especially in those areas that are essential for the emotional experience and therefore so important for hi-fi listeners. The often-missed breathing is apparent, with unnecessary interruptions removed from the music flow, and you feel yourself reminded of the elegance and charm of perfectly formed chains, where their echo is still reverberating through your synapses.

A colleague, who used the Resonator on his Spectral pre-amp, registered more foundation and colour, especially when it was placed on the external mains supply of the DMC20II. The Resonator also had a calming effect on the external power supply of the PL-P. In the final analysis the possible applications - like the lust for experimentation - are boundless.

It almost goes without saying that CD players of every price and quality class react gratefully to this round disc. But, of course, it's a moot point whether fitting a 500 euro player with a tuning extra costing the same price makes financial sense, even if this seems advisable from a sound aspect.

Lindemann's expensive 820 S rewarded the Resonator with smooth and relaxed playing, when it was positioned on the right half of the lid, whereas the Linn Majik pre-amp hardly benefited from it there, and only offered up its spatiality and more relaxed sound in both mid-tones and treble ranges when the resonator was moved to a rear left position.

The Cyrus VS 2 preamp tested in this issue played at least half a class better, stacked the string ensembles further to the back and captivated with even finer mellifluousness when the silver disc had found its rightful position at the rear of the slim casing, whereas the effect was strongly diminished when positioned further forward. Fascinating!

You should, no you must test the Resonator, especially when everything else is perfect. Send annoying resonance back to Pandora's Box, or make it disappear in finite elemente's resonance trap.