The value of isolation
Recently, noted plastic surgeon Dr. Tristan Catindig requested my best buddy and neighbor, electronics engineer John Alegre, and me to help him integrate into his stereo system a pair of 12-inch Rythmik (nothing wrong with the spelling) Audio subwoofers.
We had previously tweaked Tristan’s system to accommodate a single sub, and he was already pleased with the results. The single sub had brought a new dimension to the sonic character of his system. It seemed to him like he had just bought an entirely new and better system; it was no longer lacking in dynamics and transient.
Actually, it was not the sub alone that had afforded his system a more open and liquid soundstage. Previously, his system was still wired to a single amplifier with the drivers — Altec 604-HPLN and JBL 2404 tweeters — still using passive crossover networks. It was only when Tristan decided to go the multi-amp route that he achieved what he initially wanted his system to sound like. With an active crossover dividing the network into three and with each driver having its own amplifier for power, his system was now operating several notches better than before. The single sub could just be the icing on the cake, but the two subs took his system to an entirely new sonic level.
John and I thought that tuning Tristan’s system would again be a walk in the park. But when everything had been wired, checked and double-checked using the appropriate audio tools at our disposal, we were disappointed that we could not get his system to reproduce sound that was pleasing enough to our ears. Something was definitely amiss; we had no choice but to start from scratch and rework the tweaking. There was a low-frequency rumble coming out of the subs that was most annoying. You could even hear thuds when you tapped your feet on the wooden floor of his listening room.
By this time, we had concluded that maybe his room could not handle the amount of bass being put out by the two subs. We were already entertaining the thought that perhaps the two subs could not be integrated into his system. But if we had been able to help other audiophile friends tune their system, why couldn’t we do the same for a friend like Tristan? So, persist we did.
Alas, we noticed that it was only when playing LPs that the problem kept cropping up. With CDs, everything was just perfect. It had become clear to us that Tristan’s cartridge was picking up the noise of the reverberating floor, thus producing the feedback that manifested itself as a low-frequency rumble.
Eureka! The solution was simple: we simply had his turntable isolated from all these noises. Luckily, Tristan had some spikes left over from his other audio projects. We know that isolation footers such as spikes work, but not to the extent of really filtering the level of reverberation that the subs had on the floor of Tristan’s music room. I have always believed that isolation footers alter the sound thereby creating enhancements in your system. Just place them underneath your equipment and they will do the trick. But what about completely shutting out these annoying noises from coming out of the speakers?
There are many types of isolation footers: air suspension stands, Chinese ceramic tea cups, chunks of wood made from diverse material, floating magnetic feet, wood cones rooted with lead shots, acrylic cones, metal cones, mishmash of wood and graphite, etc.
How do isolation footers work really? Audio gadgets are being considerably repressed from providing their best because of external vibrations. The most harmful are those that arise from the ground that enter the component via its feet. Experts refer to these as seismic vibrations. These vibrations introduce specious signals within the sensitive circuitry of your components, mingle with audio signal and distort them by desensitizing the treble, diminishing the bass, muddying the soundstage and overpowering dynamics.
Isolation footers work in two ways: first, they minimize the vibration getting into the audio equipment via contact with the ledge or table it nestles upon by eating up the energy. Second, and most important, they work by expelling the vibration caused by the component itself; wearing out the vibration that emanates, for example, from transformers and/or spinning CD and turntable devices. They also dislocate and ditch chassis resonance adding weighty sonic gains.
Tristan’s system now, with a little help from the isolation technology, exhibits improvements in treble and bass extension; imaging is more focused and the soundstage is much broader. It has likewise displayed life-like dynamic swings and has enhanced the perception of an invisible system leaving the listener and the performers an intimate contact in a virtual stage.
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