|Synergizing with Greg Weaver
Back Issue Article
Paper Cups and Cable Dressing
Well, CES 2000 is behind us, and thank goodness. I dont think that I could have taken another day! In my new capacity as consultant for Harmonic Technology, I was up at 7 (which is 3 AM where Im from!), ate a sturdy breakfast at the MGM Grand's breakfast buffet, then was off to do my thing until the show closed at 6:00 PM. When the doors close, its time for dinner with colleagues and friends, which is actually one of the more enjoyable aspects of the day, aside from seeing all the new toys. Next its out to the local nightspots like the Voodoo Lounge at Rio or the lounges at the Sahara -- where, coincidentally, the adult entertainment industry was holding its annual awards gala. But I should get back to Synergizing.
Besides driving home the concept that "theres no place like home," this years involvement with helping Jim and Julie Wang set up the Harmonic Technology room also brought home the value of cable dressing. No, I dont mean cross-dressing your speaker cables and interconnects in cute little jumper outfits or dresses, but methodically arranging those crucial components to yield the lowest interaction among them.
When I arrived at the room on Thursday morning, the room sounded OK. The BAT VK-30 preamp and the VK-200 power amp provided the heart of the system. The digital front-end was the seductive and affordable combination of the Bel Canto DAC1 being driven from the digital output of a Denon DV2500 DVD player. Speakers were the Meadowlark Shearwater Hot Rods. AC conditioning was handled by four of the Richard Gray Power Company boxes. Cabling was all Harmonic Technology, including the new Magic Power cords and a prototype of the soon-to-be-available Magic speaker cable. All in all, it was a well-matched and highly musical system.
But, as I said, the room merely sounded good. Being familiar with most all of the equipment and cabling being used, I felt quite sure that we were missing a good deal of detail and microdynamic shadings. I was also convinced that the slurred rise times and loss of focus and depth were not the fault of any of the components and could be improved. Mentioning that I thought we could do a good bit better yet, I asked if anyone would mind if I made some changes after the room closed at 6:00. When I pointed out the congested rats nest of cables behind the rack and insisted that we had to get the cables off the carpet, many a consternated brow rose.
Once the room closed and we had finished dinner at the Hard Rock Hotel, I tore into it. I removed EVERY cable and started from scratch. First, I routed all the power cords FROM each component's IEC socket, directing it towards the area where the power conditioners were. Thats right, I started at the components and trailed away from them. Once the power cords were all routed, I moved the power conditioners to the spot where each of the AC cords ENDED. This alleviated the need to coil, crisscross or use sharp bends on any of the thick and hard-to-manipulate power cords, thereby making the routing sound -- and look -- better.
The next step was to reconnect and thoughtfully route all the signal cables. With the AC cords in place, I now knew where to route the sensitive signal cables to avoid radiated AC, thereby reducing the levels of hash, noise and hum likely to be reintroduced by them. Installing the cables in this order reduces the concern of having to lay a highly active (in terms of radiated EMI) power cord next to or across a highly receptive signal-carrying cable. What I am referring to is that the AC cords will impart their radiated 60Hz signal and other noise and debris into interconnects (and speaker cables) via induction if they are close enough to a signal cable. The field strength developed by the signal passing through an AC cord will easily overpower and corrupt the lower-strength signal coursing through interconnects.
Now it was time for the speaker-cable routing. Most of the time, the amplifier is on the bottom of the rack stack or off to the side or rear. This physical placement helps aid in keeping the loudspeaker cables away form the AC or signal cables. When using an asymmetrical arrangement, like having the amp off to the left side of the equipment rack (as I have at home), run the cables in such a way to avoid coiling. Though the right run may be stretched out just fine, the left side will need to be run out wider and routed a bit differently than the right. It's worth the effort.
For those of you who find yourself with a difficult situation, get creative. Move cords up or down, left or right, hang them over or around a rack upright, use spacers (more on this to come), whatever you can do to avoid close proximity of power cords to interconnects. While you are obviously aware that this alternative routing will have a sonic effect, it is usually less detrimental than the grain and hash injected by the large and dirty AC signal or the alternating fields of the speaker cables. In cases where there is no way to avoid contact, utilize a 90-degree intersecting pattern between power cord and interconnect. The use of low-dielectric-involvement spacers is desirable, and some of the best and easiest to use include paper cups and paper-towel or toilet-paper cardboard spools. You can easily cut half-moon notches in these items to assist in keeping them stable under the cords.
As I was putting the final touches on my cable positioning, I sent one of our listeners (thanks Bob) out for a sleeve of paper cups. It was time for the pièce de résistance -- getting the speaker cables off the highly interactive carpet. Ive touched on this briefly above, but there are strong reasons for my wanting to do so. All my dedicated helper could find was a sleeve of plastic cups -- which was still going to be vastly better than letting the cables lay on the floor! I had yet another helper (thank you Steve) cut two half-moon notches in the mouths of the cups (the tops) 180 degrees apart. This would let me lay the cable in the notches, with a minimum of contact to the plastic, yet hold the cable from sliding off the cup. Though placing the cups mouth down would provide slightly more stability, it would also place an inordinate and undesirable amount of plastic in contact with the cable and make it very difficult to anchor the cable to the cup.
Keep in mind that the signal passing though the carefully situated speaker cable is an AC signal. This signal (just like the 60Hz signal cycling through the AC cord) is radiated outward from the cable in a cylindrical pattern surrounding the cable over its entire length. Depending on the voltage behind the signal and the cables own construction, this pulsating field may be radiated outward as far as three or four times the outside diameter of the cable jacket itself. Think of the flux fields around the two ends of a bar magnet, and I think you will start to get the picture.
Most of you who have played with electromagnetism in a school classroom will be able to appreciate this difficulty. Running an electric current through a wire produces a magnetic field around that wire. As that magnetic field expands and contracts with the music signal, it will induce a current in any other conductor that lies within its field of influence. If a wire adjacent to it is carrying a field of its own, the magnetic fields around the two will cause them to attract or repel, just like two bar magnets. This creates a whole host of problems, which I described in "Loudspeaker Cables: Simple Passive Connection or Complex Dynamic Component." For this discussion, we are concerned with any external influences that may be exhibited on that generated field.
For the consideration of our purposes here, the audio signal that is alternately expanding and collapsing around the speaker cable must continuously cut through, and thereby interact with (to be impeded and altered by) anything within that zone of proximity. High-dielectric-involvement objects that lie within the area of that alternating field, like vinyl or hardwood flooring, tile or carpeting, greatly affect the natural and effortless expansion and collapse of that field. This can cause audible degradation to the timing of the music, to low-level detail, timbre, microdynamics and delicate spatial cues.
OK, now think about what happens when you shuffle across the carpet and touch some grounded metal. If you think about it, with the cables lying on the floor, weve given all that otherwise ungrounded potential a path into the cables. Combine that with the detrimental effects mentioned in the previous paragraph and it all adds up to less-than-desirable performance. And you thought I was just obsessing! These negative attributes can have a significant effect on things like timbre, rise times, decay of delicate signals, focus, inner detail and microdynamics.
The details, please
Explaining this phenomenon and what I hoped to achieve beforehand to our small group of veteran listeners that evening caused universal looks of incredulity and prompted numerous scoffs and snickers. However, upon firing up the system after having changed ONLY the cable arrangement and populating the business end of the room with notched drinking cups, the unabashed dropping of jaws was unanimous. The first thing one of the listeners said was, "I cant believe this! What else would you like to change?" Among the five other listeners in the room at the time, the unanimous unsolicited consensus was that the system now conveyed considerably more air, more vibrancy, more inner detail, more rapid rise and lifelike decay, greater focus and articulation, and a more faithful rendering of midrange. The two SoundStagers who stopped in the room the next morning, Todd Warnke and Bill Cowen, had some very nice things to say about the level of performance achieved by our relatively modest system.
And you should have been there when we repositioned the speakers! Enjoy, Synergizers.
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