The nature of music is vibration, if air molecules didn’t vibrate we wouldn’t hear any sound. If that was only thing in an audio reproduction system that vibrated the audio engineer’s life would be a lot easier. Because the air has to be vibrated the devices that achieve that excitement tend to move as well and that movement undermines their fidelity. It would be therefore good if this could be stopped or at least minimised. It used to be thought that if a speaker was spiked into the ground then most of its vibrations would be absorbed but when you think about it, nailing a vibrating thing to almost anything, even a solid concrete floor, is going to allow energy to pass into the floor where it will travel to anything else standing on it, as well as returning to the speaker that produced it. So spikes while they have a tuning effect because certain frequencies pass through them better than others, do not work very well, especially when it comes to keeping vibration away from the source and amplifier.
Plastic or rubber feet offer a small degree of vibration resistance while harder materials attempt to tune the nature of the energy transmission in and out of the box. Be aware that the components within a piece of electronics vibrate as well, you have probably heard transformer hum which is one form of vibration, but there are smaller vibrations coming from parts such as transistors, capacitors etc. One school of thought is that these should be drained from the casework but just how you do that without putting each one on a tombstone is not clear, the other approach is to damp the conduit between box and shelf with compliant (squashy) feet and this is where Basscontinuo’s Ultra Feet come in.
These ‘enhanced isolation system’ feet consist of two metal parts that are threaded together and have a fairly thin layer of visco elastic foam on the top with a thicker layer on the base, the bit that sticks out is 6mm deep on the Level 2 feet. They are nicely machined lumps of stainless steel with different damping materials at top and bottom. These feet are available in four levels to suit components of different weights, level 2 is for 10 g to10 kg, level 3 for 10.1 to 20 kg, level 4 for 20.1 to 40 kg and level 5 copes with gear that weighs up to 80 kg. These amounts are for sets of four.
Theory dictates that you need a certain amount of compression in a spring to give isolation down to a certain frequency, to get down to the lowest frequencies requires a lot of compression, 30mm for 2Hz, something that can’t be achieved without a spring, hence suspended subchassis turntables such as the Linn LP12. So the foam in Ultrafeet reduces high frequencies but cannot stop lower ones, but as we’ve seen with many such products in the past this can be beneficial. I put the Level 2 Ultra feet under a range of components to see what the effects would be.
Sound quality
I should mention that the equipment racks in my system have spring isolation already because this does benefit sound quality in my experience, in racks that are not isolated the effect would presumably be greater. The first component I tried is so light and small that I put just one Ultra foot underneath it, the Stack Link II network bridge weighs only a kilo and balanced fine so long as no cables were tweaked. It has thin cork feet and was sitting on a glass shelf, the benefits of adding an Ultra foot included a surprising increase in openness with the soundstage expanding before my ears quite clearly, accompanied by increased impact from drums. With the rather more appropriate 8 kg Merason DAC1 whose soft plastic feet were also on a glass shelf the effect was similar, here the presentation became more 3D, imaging getting more solid and real and this allowed the placement of instruments and voices within the mix to become clearer. There was also a perceptible relaxation, not huge but worthwhile. Returning this DAC to its standard feet took away the openness and reduced the sense of delicacy in its presentation.
Next up was a Melco N1-A music server (7kg) which contains spinning hard drives among other electronics, this has wooden feet (yep) and sits on a wooden shelf. Putting the Ultra Feet underneath it increased the sense of speed, the playing on Joni Mitchell’s Drycleaner from Des Moines became tighter, funkier and much more engaging. The Melco is typically a bit on the relaxed side when it comes to timing but decoupling it from the stand had a remarkable effect, making the music it produced distinctly more enjoyable. Trying them with the streamer in the system, an Auralic Aries G2.1 which already has sprung feet albeit stiff ones made a difference too, not as big as the server but there were gains in high frequency resolution which enhanced coherence, bass definition and focus.
In theory a turntable which earns its place by virtue of reading vibrations (in a vinyl groove), and preferably only those vibrations, should be more sensitive to isolation than anything else. But that depends on how well the turntable is designed. On the Rega P10 the answer would appear to be ‘remarkably well’ because the Ultra feet while they relaxed the sound slightly and allowed it to reveal more fine detail, didn’t do as much as they had elsewhere. For instance with the Rega Aria phono stage where they proved to be highly beneficial, here there was a stronger sense of coherence and focus to the sound that made vinyl even more engaging, this proved the biggest gain on the analogue side.
It would seem that even with a well isolated rack adding more damping and isolation with the Bassocontinuo Ultra feet can be beneficial to a wide range of components. These feet are nicely made and presented using materials that should remain compliant for many years to come, not always the case with foam. What’s really interesting is how their benefits varied with component types, openness increases with most of the digital devices whereas other factors were enhanced with analogue ones. But in both cases there is an uplift that warrants this sort of expense in all but the most modest systems, and even there they might well be of greater benefit than a similarly priced cable.