August 1, 2009

Trick or Treat or Tweak?

I was in India from November 1975 to April 1976, courtesy the Trinidad and Tobago Bureau of Standards (TTBS). The program included an intensive course on standardization with the Indian Standards Institution (ISI) and, more important, a six-week stint at the National Physical Laboratories (NPL) in New Delhi. This was, by far, my most fascinating professional experience.

One morning I was invited to have tea with Dr. M. Pancholy, Director of Acoustic Research at NPL. I had already been in and out of his anechoic chamber many times, as TTBS was interested in establishing similar facilities at home. Dr. Pancholy poured boiling water over the tea bags nestled at the bottom of two cups, then covered the cups with their saucers. Two minutes later he removed the bags, then added milk, sugar, and cloves.

"Why did you cover the teacups?"

"To retain the aroma," he replied.

I have followed his procedure ever since. It does make a difference to the taste of the finished product. Is this trick a treat, a tweak, or is it both?

Let us define a tweak as a subtle addition to or subtraction from an audio system that allows us to hear more of the music. Let us then assume that we own a basic stereo system consisting of a CD player, a preamplifier, a power amplifier, a pair of loudspeakers, and all associated cables and interconnects. How do we tweak this system?

XLO/Reference Recordings Test & Burn-in CD

It’s amazing how many of us fail to connect equipment properly. How many more do not read manufacturers’ instructions until a problem is encountered? For these and many other very sound technical reasons, the XLO/Reference Recordings Test & Burn-in CD (Reference RX-1000) should be an integral part of every audiophile’s gear.

There are many similar CDs in the marketplace, but I guarantee that anyone using this disc competently will achieve satisfactory results. I religiously play it at moderate levels in repeat mode every six months or thereabouts, when I’m away from home. After a few hours, the sonic results are always remarkable -- somewhat analogous to polishing and buffing a car after washing it.

The disc helps you do the following:

• Verify that your system’s left and right channels are properly wired for all input sources
• Ensure that your stereo system is properly balanced
• Ensure that your loudspeakers are wired in phase
• Tweak the placement of loudspeakers relative to your sweet spot
• Improve the acoustics of your listening environment, where necessary
• Demagnetize your entire system
• Burn in new components
• Enjoy nine music tracks from the Reference Recordings catalog recorded in HDCD format by engineering wizard Keith O. Johnson

Cables and Tiptoes

The subject of high-resolution loudspeaker cables and interconnects has been on the front burner of the high-end audio industry since the early 1980s. These components do not carry direct current, but complex signals of varying amplitudes and phase differences within the audioband, which ranges from 20Hz to 20kHz (and sometimes higher).

In the physical phenomenon called the skin effect, higher-frequency components of an audio signal tend to travel on the surface or skin of these conductors, resulting in the loss of important spatial information critical to enhancing and optimizing the sound of a high-end system. Engineers have researched, defined, and refined new manufacturing technologies to overcome this and other problems. High-resolution cables and interconnects now easily pass critical information contained in the audioband with minimum loss or distortion. Since the ’80s, an entire lucrative industry of cable manufacturers has mushroomed. In the ever-expanding world of high-resolution audio, other ancillary accessories, such as connectors, plugs, and sockets, have been similarly tweaked to enhance their sonic performance.

In many systems, cables, interconnects, and their attendant connectors cost as much as or even more than the main components. In the quest to hear more, no holds are barred! For me, once a tweak makes sonic or scientific sense, I will implement it. A very good example is those sharply spiked conical feet commonly called Tiptoes.

These have definitely improved the performance of my Oracle Premier turntable. Some manufacturers, notably Simaudio of Canada, use similar feet to isolate all their components from external vibrations. The obvious inconvenience of installing equipment loaded with these devices is outweighed by the sonic benefits derived. Apart from which, Tiptoes enhance the overall aesthetic of electronic components.

Preventive maintenance

In the tropics, there is a perpetual battle with heat, moisture, insects, fungus, and mold. Humid conditions can have very adverse effects on certain types of materials used for making loudspeaker surrounds, which can disintegrate; the driver cones themselves can thus become detached.

Many customers are none the wiser and continue playing their systems just as before. I often wonder what they hear. Clearly they do not have golden ears. Borrowing a term from the game of bridge, I would say that every audiophile needs to develop and retain a keen sense of what we may call table presence.

For our purposes, table presence can be defined as the art of knowing instinctively when something is wrong with a system. We have to know when to buy, when to tweak, and when to sell. Every audiophile should be duty bound to remove loudspeaker grilles, clean baffles, and inspect drive-units every six months or so. This is not a tweak so much as preventive maintenance.

Tweaking your sweet spot

A sweet spot is the apex of the two equal sides of an isosceles triangle, these sides formed by two imaginary lines drawn from the center of each speaker. Before auditioning music, sit at the sweet spot and open your eyes. Everything in front of you should be a pattern of symmetry. Use a tape measure to adjust the positions of your loudspeakers relative to the front and side walls until you are satisfied that symmetry has been achieved.

Play track 2 of the XLO/Reference Recordings Test & Burn-in CD. The narrator will say "Balance test: My voice should be centered between your two loudspeakers, tightly in focus." If this is not the case, then adjust the balance control of your preamplifier until you get a satisfactory balance. Note this setting. This is a very simple, yet effective way of defining and tweaking your sweet spot.

Some loudspeakers are designed to be fired straight ahead, others are designed to be toed in. You can form the hypothetical isosceles triangle either way, and the test CD will work just as well to help you to locate and tweak that sweet spot. In both instances, you should audition one of your favorite recordings immediately after the tweak. When you have it right, your speakers will seem to disappear. If you then close your eyes, you’ll "see" a breathtaking array of palpable sonic images. You’ll feel as if you’re part of the experience, especially with live recordings.

High-resolution line conditioners

Often, audiophiles become engrossed in tweaks to improve the quality of what they hear, and forget that the removal of unwanted artifacts is just as important, sometimes even more so. This ensures that the resulting sonic canvas can be painted on a black background.

The sonic effects gained from the use of high-resolution line conditioners can be spectacular. Most of us aren’t aware that some undesired sonic artifact is having a deleterious effect on a system’s sound until it’s been demonstrated. Imagine that, after breathing polluted air all your life, you take a trip to the mountains or the seaside, where the air is fresh. That’s the sort of difference a line conditioner can make.

A line conditioner is a device installed between the AC mains supply and your components. As far as I’m concerned, it is not a voltage regulator or stabilizer; those devices are designed to provide as steady an output as is economically possible from wildly fluctuating mains voltages. Line conditioners are specifically designed to remove or significantly reduce spurious mains-borne noise superimposed on your supply. They also attenuate radio-frequency interference that can be easily picked up by your audio equipment. Line conditioning can be considered analogous to filtering the gasoline before it enters a car’s carburetor.

With the filtering out of spurious, undesired grunge from the mains, you’re apt to discover a whole new world of sound. You begin to appreciate the subtleties, dynamic contrasts, and nuances that exist in some recordings. The resolving power of your system seems to have suddenly increased dramatically. A high-resolution line conditioner is no mere tweak but an absolutely necessary treat.

Sometimes the results of a particular tweak aren’t immediately evident. For example, components may need to be burned in for several hours, days, or even months. Remember that, at the highest level, most improvements are subtle. You have to be patient; only then will you hear more. I believe that the greater the resolution of your system, the easier it will be to hear incremental changes.

In my opinion, a high-resolution line conditioner effectively extends a system’s dynamic range by lowering its noise floor. If you don’t already own such a device, do your homework, prepare a budget, and acquire one at your earliest convenience.

The final treat

Finally, treat yourself to Carol Rosenberger performing Water Music of the Impressionists on a Bösendorfer Imperial Concert Grand (CD, Delos DE 3006). Start the disc, sit in your sweet spot, and close your eyes. Relax, and listen attentively.

Twenty-six years ago, the New York Times described Rosenberger’s artistry as "ravishing, elegant pianism." I would like you to conjure up your own phrase to portray the sound of what you hear. May I remind you that this sublime instrument carries nine extra keys in its bass register?

. . . Simeon Louis Sandiford
simeon@ultraaudio.com