New Methods for Quantifying Sonic Performance: Part Two

Part Two: How to Use Subjective and Objective Methods to Quantify System Performance

Equipment report
Solid-state power amplifiers,
Tubed power amplifiers,
Solid-state preamplifiers,
Tubed preamplifiers,
Digital-to-analog converters,
Music servers and computer audio,
New Methods for Quantifying Sonic Performance: Part Two

In discussion with Bruce Jacobs, the use of granite shelving in our systems was questioned. He suggested that the Stillpoints product might sound better with a dense piece of flooring bamboo inserted between the footer and the granite. We obtained 4" x 4" x ½" squares of this material for additional testing. When the Stillpoints Ultra footers were used in our preferred inverted position in combination with the bamboo between the footer and the granite shelf, we instantly observed degradation in SQ, with a loss in transparency and focus, along with a 13" height drop in our soprano measurement. When we used the bamboo with the same footers in a non-inverted position, the SQ was found to equal that found with the inverted footer position in direct contact with the granite shelf, so the results shown in Table 2 stand as reported. Nonetheless, if you are using wood or other types of shelving material, it is best to try all footer products in both orientations—you must do the experiment yourself to determine the best sounding orientation in your particular circumstances.

Although we chose just the PWD DAC for testing the effect of footers on sound quality, we would point out that the addition of footers of some sort under each piece of equipment in the signal path is cumulative. Jacobs also pointed out that using the same manufacturer’s footers throughout the system (rather than mixing them as we did in out tests) can produce synergistic results. To test for this possibility and also to see whether there might be any subtle but cumulative negative properties as we increased the number of support devices, we compared a system equipped entirely with the Nordost titanium Sort Kones against one equipped entirely with Stillpoints Ultra SS footers. In addition to assessing height, we also paid close attention to our subjective criteria, particularly dynamic range and harmonic overtone structure.

After the more limited testing shown in Table 2 and the near identical performance of the two brands of the more costly competing footers, we were truly surprised at the subjective SQ advantage exhibited by the Nordost titanium Sort Kone-equipped system compared with the Stillpoints Ultra SS-equipped system (see Table 3, lines 1 and 2). Despite this obvious sonic difference (estimated to be somewhere between 30 and 50 points better on our subjective scale, a difference falling within our definition of the very large category of sonic significance) we could detect no significant difference in our soprano height scale. We suspected that we might have run out of available headroom with this sonic marker as a result of a real recording limitation in capturing the original performance. To test for this possibility we decided to handicap the system performance in order to reduce the height of the sopranos by making certain modifications to the standard system setup. We removed the BBs from the top of the DAC (see Fig. 2B) and replaced the Wireworld Platinum USB cable between the computer and USB to SPDIF adapter with a generic computer-grade USB cable. We now could observe a major soprano height difference of 23" while still retaining a subjective SQ point advantage in the 30 to 50 point range observed with the Sort Kones prior to handicapping.

We chose to focus our attention on the Nordost and Stillpoints products because, in our experience, we believe these two brands represent the best of the breed of support devices on the market today. As we were unable to detect a sonic difference when comparing the effect of the Nordost titanium Sort Kones with the Stillpoints Ultra SS footers on just the DAC (see Table 2), the measurements and SQ changes shown in Table 3 came as a complete shock. Our involuntary, non-intellectual, non-left brain emotional response was totally unexpected and unmistakable.

While we propose that our height measurement system is a new and very useful way to rank performance variations, a tape measure (or for that matter, an oscilloscope or distortion meter) cannot quantify or evaluate the black-and-white difference that exists between being emotionally connected with our music versus not connected. Only the human brain has that capacity.

We would caution that these results could vary with the composition of equipment stands and the internal construction of the equipment used. For example, differences in the isolation of internal circuit boards, the thickness and resonant frequency of circuit board material, the proximity of circuits to shielded or unshielded power transformers, and even the layout of circuit traces could yield different results.

The conclusion readers should draw from our particular findings is that they must compare different footers in their own systems if they want to get the best results. The most important fact is that adding good footers throughout a system can very easily be more beneficial than spending far more on a particular electronic component, and can improve the performance of any existing device, regardless of price. We want to stress without equivocation, that, in our opinion, the full effect of treating a complete system with the best footers one can afford is revelatory and the sonic value they confer on any good system is money wisely spent.

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