[SoundStage!]Synergizing with Greg Weaver
Back Issue Article
July 1998

(Another) Fistful of Freebies

Up...up...and away!

One of the most harmful things to your audio signal as it passes between either your source component and preamplifier or amplifier and speakers is the disturbing interference offered by some unpredictable dielectric interaction or an imposed field effect. Yet, there are some very easy (read: cheap) and effective ways to attack and thereby neutralize this kind of degradation.

With interconnects, one of the worst things you can do is run a power cord side by side with a cable carrying the delicate line-level signal from a source component to your preamplifier. This is often taken care of as easily as just re-routing your cables. Separate your line-level cords (component patch cables) from your component power cables. For example, you may be able to group all your power cords on the right-rear of your equipment rack and all your signal cables to the left. This will have the effect of keeping the much stronger radiated fields around your 120-volt AC cables from inducing any noise or creating an impedance problem for the more delicate signal coursing through your interconnects.

This ideal left/right separation isn’t always feasible, given the fact that some components just won’t follow the pattern. In these more extreme cases the best results are obtained by having any cables that must come near to or into contact with each other cross each other’s path at a 90-degree angle. This provides a minimum area of contact between the two cables, thereby minimizing their field effects on each other. The sonic benefits derived by separating line-level and AC cables typically include greater detail, better imaging and staging, enhanced low-level detail and resolution and a more coherent signal—from top to bottom.

One of the more audible and annoying problems with loudspeaker cables is one caused by the deleterious dielectric interaction with your floor covering. Most thick carpets are made of materials that, while designed to wear for 20 years and not absorb pizza sauce, have extremely poor electrical characteristics. Even bare wooden floors are considerably less than desirable. Because your cable lays on this material, half of the cylindrical field generated around the cable as it courses to your loudspeaker is impeded by the flooring, often creating a gross slurring of the signal. The sonic distortions here include timbral imbalances, brightening or dulling of the bandwidth and large discontinuities in frequency arrival times as well as all the problems listed above relating to interconnects. So you need to get the cables up off the floor.

Some people in my experience go to serious extremes in this area because of the significance of the interaction. Pierre Sprey, for instance, the brilliant recording engineer and founder of Mapleshade Productions, uses monofilament wire (fishing line) hanging down from his ceiling to hold the wires off the floor, effectively building a suspension bridge from the amp to the speaker system in his room. This might be a bit much for the novitiate and is sure to upset the significant other.

Since paper has very low dielectric interaction, one of the easiest fixes is to use inverted paper cups under the wires to hold them up off your carpet or floor. You can even use spent toilet paper or paper towel rolls. Just lying them on their sides is not recommended though as it doesn’t afford the necessary height, and in this position, they can flatten easily over time. Cut them into at least 4" lengths and stand them on end. You can cut some half round or V-type notches into one of the two ends so the cable doesn’t fall off so readily.

Even more attractive and effective is dark-gray polystyrene pipe insulation, which is sold in 6' lengths in hardware or building-supply stores for under a buck a length. The stuff comes in a pre-formed tube, split down the length of one side for easy installation around your copper piping. It cuts easily with a utility knife or scissors and is likely to be both more effective and appealing to the significant other than upside down Dixie Cups!

Close your eyes...really!

One way to really "see" your soundstage and find out how your room is set up is to turn out the lights or close your eyes while listening. Don’t laugh! I’m completely serious. The visual stimulus can have a VERY STRONG effect on what you hear.

The effect is so strong that one of the listeners (the Sak-man) in my local listening group, the Southern Maryland Irregulars, had to change the original orientation of the room he designed and built for listening! He initially planned the room so that his speaker placement would allow him to look out through his large windows into the beautiful view it afforded. The problem was that he couldn’t seem to balance the left/right stage. The visual aspect of the room was skewed and it threw his whole aural perspective off.

Turning off the lights or even just closing your eyes while listening will let you ignore that stimulus and simply judge the system performance. I always listen with my eyes closed. In fact, at HI-FI ‘98, Jeff Joseph had to call to me by name to get my attention while listening to his demo so that he could hand out his promo literature and a prize I won’t soon give up—a Joseph Audio pen!

Try closing your eyes while listening to your favorite album/CD and try to reconstruct a three-dimensional image of the performance. By using only your sense of hearing, attempt to locate the drum kit in relation to the singer, or locate the backing vocalists in relation to the lead guitar or lead singer. With only the sonic information as your guide, see if you can tell where the crash cymbal or cowbell is in relation to the rest of the drum kit. Is the rhythm guitar in front of the drum kit but to the left and behind the lead guitar?

With your eyes still closed, listen even more closely now. Does that voice sound real, or does it sound as though the person is speaking through a megaphone? Does the piano sound clean throughout the entire keyboard, or do certain notes ring or knock as they are played? Do the drums sound punchy and tight, or do they rattle and resonate as the heads are hit? Do the cymbals come through with crisp attack and sharp definition or do they "tizz" and sound raspy when struck?

If you listen to classical music, are the violins in front of and lower than the kettledrums? Do the cellos emanate from in front of and below the brass instruments? Mentally reconstruct the soundstage. Try to determine the instruments’ placement in the space between (maybe even outside) and to the front and rear of your loudspeakers. You will find that deliberately listening for such things will sharpen your listening acuity greatly and help you assemble that dream system that much sooner.

What’d you say?

One fact that no one can dispute is that once your hearing is damaged, there is no way to get it back. Hearing protection is one of the most overlooked and seriously necessary ways to let you enjoy your music system throughout your lifetime.

Let’s look at something as seemingly innocuous as lawn care. When measuring the volume of a lawn tractor, a push mower and a two-stroke weed trimmer, some very scary numbers came up! The lawn tractor, with the throttle on high and the blades engaged, read 99dB at the driver’s seat. The push mower registered 97dB, while the gas-powered trimmer came in at a whopping 97dB at idle and escalated to over 105dB when trimming. My yard takes about an hour and a half to cut and another 20 minutes to a half-hour to trim – at least once a week. Where else might you find a need? Do you ride in your car with the windows or (those of you with convertibles) top down? Do you work in a loud environment like a factory or machine shop?

You should be aware that national standards suggest that exposure to noise levels of only 85dB starts to cause damage within just five minutes and that levels of 95dB or higher, the damage begins as soon as you are exposed. The longer you are exposed, the higher the degree of damage. Duh! Do I have to say this? USE HEARING PROTECTION whenever you can.

Cheap and effective protection is available at sporting goods stores or in those departments of large discount stores. The shooter type of "headphone" is bulky and expensive, running as much as $50 or $60, but they are convenient and effective and can lower outside noise by as much as 30dB. The easier and more affordable method is the foam earplug. These are usually less than a dollar a set and are easily taken with you where ever you may wish to use them. You simply take these little foam devils, roll them in your fingers to compress them, then insert them into the ear canal. Once in your ear, they try to re-expand to their original shape, blocking incoming noise by about 25dB or so.

Having had the bizarre experience of working in a factory with a background noise level in the 90dB range in my late teens, I found that the plant nurse handed out the little foam devils to any who would take them. Surprisingly enough, very few people took her up on the offer. I was issued a set at a car stereo competition I judged some years ago that came with a nice little carrying case which I have managed to hold onto, so it is easy for me to have them with me where ever I go. They require washing from time to time or they will get kind of vile looking, but they clean up with soap and water in a snap. Or, given the affordability, you can just toss them and get a new set.

No matter which way you chose to go, START USING HEARING PROTECTION NOW if you don’t already do so. Ten years from now you will be very thankful you did. I have been using these foam plugs for the past twenty years when mowing the lawn, using power tools, riding motorcycles - even while attending some extraordinarily loud rock shows like Pink Floyd and the Who. You know what? It didn’t affect my enjoyment of any of those events in the least. Yes, occasionally it has sparked some ridicule and teasing form those less informed, but my ego can take it. My ears, on the other hand, cannot.

...Greg Weaver
gregw@soundstage.com

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