[Review] Les Davis Audio 3D-2 vibration dampers

Les Davis Audio 3D-2 vibration dampers

Simple, silver, sandwiched, sonic sweeteners

Product: vibration dampers
Manufacturer: Les Davis Audio - info@lesdavisaudio.com.au
Price: approx. AU$ 100 inc. GST for a box containing 16 “footers” - US$ 125 in the U.S.A. - (Currency conversion)
Reviewer: Richard Varey - TNT New Zealand
Reviewed: March, 2017

Introduction

This is one for the engineers among us. I first heard about this product from one of the exhibitors at THE Show, recently held at Newport Beach, California. It was used in a formidable music playing system, under the Colleen Cardas “Down Under Audio” banner that showcased Australia and New Zealand products: loudspeakers from Brad Serhan of Brigadiers Audio, Simon Brown's The Wand Master tonearm, amplifiers by Gary Morrison of Pure Audio, and the Döhmann Helix 1 turntable. It seems that the exhibit was highly successful, as the team put together a great sounding system that caught many visitors by surprise. There are a number of very positive reviews from the show.

The science behind

The 3D-2 discs are a composite layering of an industrial grade soft aluminium foil constraining layer and a pressure-sensitive viscoelastic polymer. This constrained layer damping (CLD) suppresses vibrations in precision applications, having been developed as effective engineering for the military, and aerospace and aviation industries, and also used in automotive sound-deadening mats to kill resonance in vibrating panels. This optimum combination of viscoelastic damping material sandwiched between stiff base and constraining layers is difficult to assemble, and this proprietary composite formulation has been in development by Les Davis for ten years through a combination of materials science and trial-and-error testing. Vibration and “ringing” is dissipated as heat as the shear strains deform the damping layer. The loss is high in thin configurations and damping is most effective at the edges of sheets.

Resonance is a recurring theme in current audio equipment design, both analogue and digital. Undesirable resonance adversely alters the sonic character of audio. Shearing forces are unaligned forces pushing one part of a body in one direction, and another part of the body in the opposite direction. When the forces are aligned into each other, they are called compression forces. Damping is the effect of dissipating energy in shear stress and strain forces of vibration as heat in the resistance of the attached material, thus reducing motion. So shear in micro-movement is an issue for designers. This minute side-to-side movement seems to have an effect on timing in a playback signal. Les asked: «What is happening to the music being played with the constrained layer feet compared to the music that you hear when not using it? Does the damping effect colour the music in any way that makes it more appealing or does it enable the information that is contained in an electrical signal to be fully realised?». Les is strongly convinced that it is the latter. Many other products that are being used to isolate vibration, such as Vibrapods, colour the music by softening the bass, thereby making it warmer, whilst others accentuate the mid-range and push forward the vocals. Both effects impart a pleasing effect for some ears, or they brighten the sound and make it more pronounced. Les believes that is not happening with the 3D-2, and rather than colour the music, it allows the full details to emerge. And that relates to timing.

Les also told me that changing the number of layers and part of the fabric will have a powerful effect on how it works. You can quite literally tune a hi-fi system, i.e. more bass, less bass, more high-end, etc. To do that would be to obscure its outstanding potential though, and, despite requests, he did not pursue it during development. The goal has always been to improve the hi-fi system in its performance in reproducing the natural timbre of music. It has the ability to let the music breathe, with more soundstage, more detail, and a far greater sense of timing. The timing aspect is what Les concentrated on when deciding on the final composition of the product, and that stems from him playing music.

If the constrained layer mechanism of the 3D-2 allows greater detail to emerge without colouration, then what is happening in an audio system that impacts its performance? External vibration is quite well understood, but in this case it is not so much about what is happening on the outside of the unit, but on the inside. Micro vibrations from the electrical and mechanical functions of the unit impart colourisation. Energy either transient or stored needs to be removed from the chassis. The 3D-2 can be used under turntables and CD players (affected by mechanical energy and by electrical energy) and under amplifiers and power supplies (impacted by electrical energy only).

Most hi-fi systems are tested on a parameter of frequency response or on a total harmonic distortion figure. And we likely all know of components that have supposed great technical specifications but sound awful. Why is that? Les thinks the missing element is in the timing of the audio signal. The micro vibrations upset badly the factor that is so very important in music (go to any music school teacher and find out how much emphasis is placed on time). Yet it is very hard to test.

The human brain uses the sound that is transduced via the ears in a very detailed and acute way and it can discern the difference quite clearly between the two audio signals that might appear to be identical in electrical test terms. And probably the best way to describe that is in considering the way that we can judge distance by sound difference, even when a source is behind us. Having this detail put back into an audio signal gives the clues required for a brain to picture the sound stage of the music played. Not only that, but the timing in the music itself is a lot more detailed. The musicians now appear to be playing more together, and great musicians have great timing. A noticeable improvement is in the bass and upper bass. Without a doubt, Les tells me, micro-vibrations impart the smearing that you get in the upper bass and midrange. Most systems will impart the lower bass, but the bass gets lost when the players move up into the higher register.

There are a lot of products that are marketed for vibrational control in hi-fi. However the 3D-2 is something different. Many products such as Stillpoints are very expensive, but this product is priced to be far more affordable. Each box contains 16 feet. To use them, they are simply placed in a stacked pair (for the optimum performance to the designer's ears) under each foot of a CD player, amplifier, pre-amp, power supply, turntable, etc. So a box will treat an amp and a CD player. With speakers you can use it under the feet of a stand, but you need to be careful. It can be too much of a good thing, according to Les. The material can be applied internally to loudspeaker panels, and indeed there is a new loudspeaker being developed with Brad Serhan using the damping sheet as a gasket to seal the drivers to the front fascia.

The London-born developer Les Davis plays lead guitar and has been playing now for almost 40 years, currently around the pubs and clubs in Sydney. Les' interest in music tends to swing from playing to listening, although both have now combined and in so many aspects have informed each other. He was a co-owner of a Sydney hi-fi store, The Music Room, that ran from 1988 to about 2004. The business was run by a motley assorted crew of mechanical engineers, a solicitor, and Les looking after finance. The store had a tendency to be a hotbed of experimentation as much as a retail store. The team rebuilt and built CD players and turntables, and rewired and rebuilt speakers, and this was much more where the fun was had. Then there were the many debates as to what a hi-fi system should be, basically to play music, not replicate sound, and what musical elements one should look for in a well-functioning system. Many a late night was spent in debate.

Out of this environment came the experiments in constrained layer damping in use with audio components. This actually happened just after the shop closed. Of all the ideas that were generated, this simple product not only showed the most promise, but easily was the most consistent performer in that it gave a universal improvement no matter what component or system it was partnered with.

In 2015, Les revisited the concept and started to experiment more with it, resulting in changes to the original components and its construction. A lot of experimentation occurred. The science of materials is well known, yet what isn't so well understood it seems is exactly how materials react when placed alongside each other in a constrained layer format. Les discovered that layering the fabric in a certain manner and using certain materials improved its effectiveness to the point where he was getting pretty startling effects.

The issue of how many layers of material to use to obtain the best effect has been an ongoing question, addressed over many years. Early experimentation with this concept immediately highlighted that layering the fabric improves its performance, but also that a point is reached when its effectiveness starts to not just diminish but it can alter the characteristic of the performance of the audio unit that it is being matched with. The first samples where a simple three layer. Adding layers when done correctly not only enabled it to get the best sound, but was more capable of maintaining its ability to perform under compression; that is, under heavy components. As the disc is so thin, I wondered if there is a limit to weight for the desired effect. Les Davis told me that, in his trials, the composite has worked well with equipment up to 30 Kg over extended periods of time.

The next step was to experiment with different fabrics to use in its construction. The issue, as explained by Les' engineering friends, is that as much as the concept of constrained layer damping is known and the mathematics involved is formulated, what is not readily known is how materials react with each other. And there is only one way of finding out - testing them. Judgements as to what is the best outcome that this concept can yield were made by musician Les, always referring promising test samples to those whose judgements he trusts, such as the award-winning speaker designer Brad Serhan. A version with seven layers yielded spectacular results, incredibly open and dynamic with great sound stage. But it was prone to glare. It was nearly there, but not quite right. Now at this point, being so close yet so far and being somewhat frustrated, Les, on a whim, decided to just place two pieces of the seven layer version, one on top of the other. And that was it. He could not fault its performance in any manner. Not only that, it was so versatile. It gave, to his listening, a sensational performance under a CD player, amplifier, TT, any separate power supply, and as he and others, such as Tara Labs' Matthew Bond have discovered, under a laptop PC. If you want a high-end performance from digital audio, you must use this, urges Les.

Les knows that he could build a fabric that would act like a flavour to the sound, adding bass, top end sparkle, softening the midrange, or whatever. But he doesn't believe in doing this, and never set out to do it. Some people have done just this with the 3D-2, using one layer under the front feet of components and not at the back. So they have effectively tuned their hi-fi for their personal taste, although Les strongly recommends using two stacked under each foot.

Les conferred with long-time hi-fi buddy Brad Serhan as to effectiveness and they were both convinced that it was something that all users of a hi-fi system who wished to improve its performance would be very interested in. Les showed the concept to Marc Phillips, of Colleen Cardas Imports (it was not yet a product at that time), and he agreed that it was something that they would be very interested to distributing in the US. And with that it became time to convert the idea into a product. Six months later the product, that Les has called 3D-2, was ready for THE Show 2016.

[Les Davis Audio 3D-2 vibration dampers]

In use

As I removed the eight samples from the packet, I was immediately struck by how surprisingly thin and lightweight they are. Once placed under the feet of my SACD player they are out of sight. A significant sonic improvement is claimed. Would I hear the noise floor lowered, improved clarity and musicality, with more visceral impact and coherence? An A-B test can be done very easily, by inserting and removing the footers. So that's exactly what I did repeatedly. And it's true, music reproduced by my modest Pioneer D6 player sounds magnificent. I then placed three pairs under my Clearaudio Emotion turntable, and was struck by the solid and rich soundstage presented by The Wand Plus and Hana EL cartridge. This was the most immediately striking effect.

I've also put them under my Sachem v2 monoblock amplifiers, and a Nimitra digital music server (on loan from the Fidelizer guy, and the subject of a future review), as well as an icOn passive TVC (see review here on TNT-Audio). Then I followed Les' advice and placed a set under my Windows 10 laptop PC on which I run Fidelizer and JRiver MC21 playing through either a Styleaudio Carat Peridot USB DAC or the Mamboberry media player (see my recent review). The damping of vibration of the PC case is very apparent. I very much like what I hear.

Conclusion

As a science graduate my studies included physics, metallurgy, crystallography, and thermionic and solid state electronics, so I have some fairly well developed understanding of materials in relation to electromechanical performance components, circuits, and assemblies. The micro-vibration theory seems highly plausible for the mechanical and moving parts of an audio system, including turntable chassis and motor, pickup cartridge, and tonearm, as well as disc drives, speaker drivers, cabinet panels, valves, wires, and circuit board mountings. Where I am less clear in my understanding is in active components, such as integrated circuits, diodes, capacitors, and inductors. How might the performance of these be affected by vibration? I'd love to hear from any engineers who can explain the effect.

As always, I resorted to listening to my music. My experience with the 3D-2 dampers suggests that experimentation is well worthwhile, relatively low cost, and in certain circumstances both instant and easily discernible. I am truly grateful to Les Davis for lending his tuned ear to this perennial audio problem and for his persistence in bringing this easy upgrade option to the market.

In Australia the 3D-2 vibration dampers are available from Len Wallis Audio in Sydney. The price is around AU$ 100 inc GST for a box containing 16 footers. Design Build Listen is the New Zealand supplier. In the US, the product is being distributed by Colleen Cardas Imports. I know that it is available in stores in New York State (including Tenacious Sound) and in San Francisco at this time, with more to follow, priced at US$ 125. There are no plans to sell direct to users.

Thanks to Les Davis for answering my science questions, and the final word is from Les: «For me the whole process has been truly an “ear opener”. Yes, removing micro-vibrations is very important in audio. But how you do it is just as important». Hear, hear to that!