Take a surface, be it the floor or a table, on which your hi fi component is placed and it is desired to reduce the vibration from the support to the equipment. The way this is done is to put “some stuff” between the equipment and the supporting surface. There are three possible outcomes.

1. The vibration in the equipment is more than the vibration in the support. If this were the case; then the energy crisis would have been solved! Something for nothing! More out than went in! Free power forever! Sorry, not possible.
2. The vibration in the supported equipment will be the same as in the case of no stuff. The chances of this are one in a million because something has been changed, therefore, the only possibility is that:
3. The vibration in the equipment is less than the vibration in the support, which, indeed, is the case.

In the case of Hi Fi, there are many products (stuff) on sale that does attenuate vibration. Be it spikes on glass, wood and slate, aluminium spikes in cups, ball bearings in cups, solid plates separated by compliant sheets, lead, Bluetack, sand, marble, concrete – the list is endless. It is also known that by stacking more stuff a better result may be obtained.

The intelligent approach is to optimise the stuff and you will no doubt not be surprised to learn that that the Victorian engineers came up with the solution -. the spring! The spring may be anything “springy”, from elastic, rubber, coiled steel, straight steel, air-bladders to flexible wooden strips – as long as it has sufficient spring, or compliance, realise a mechanical low pass filter, i.e. a system that holds the equipment up against the force of gravity, but does not allow deleterious vibration to pass through.

Any spring mass system will oscillate at its resonant frequency.  At frequencies below resonance, vibration will pass through. At resonance, vibration will be increased and at frequencies above this, vibration will be attenuated. Therefore, it is desirable to have the resonant frequency as low as possible to block as much vibration as possible. Ideally, for audio, this should be about 2Hz in both the horizontal and vertical planes and with a damping ratio of about 0.16. This will give an attenuation of about 25dB at 10 Hz increasing at 20dB per decade above. This will ensure excellent isolation for the deleterious audio system vibrations, which range from 5Hz to 500Hz. The support should feel soft and wobbly to the touch; the more give under load and the more softer the feel, the better. Just as in the case of a car with a softer suspension and more give under load, the smoother will be the ride. The Townshend Audio range of Seismic Sink isolation products resonate at about 3Hz are most stable, are “user friendly” and can be realised in attractive practical reliable maintenance-free objects of great beauty and bling.