Fine Tunes #36

Paul Kelly (pkell4@earthlink.net) recently sent me a most interesting e-mail titled "Cones, Stones, & Groans." I'll share it with you now, as I gave "Sean" (bigfoot1@corecomm.net) a chance to expound on cones and how they work under equipment in the February "Fine Tunes." After reading through all the "Fine Tunes" archived on the Stereophile website (I thank him for his positive remarks), Paul wrote:

"A few observations: Almost everything finally resolves itself to simple physics, which ultimately govern the universe. Unfortunately, we all know a great many things that are actually untrue; eg, 'Edison invented the electric light bulb.' False. There were many electrical lighting devices extant before Edison's bulb. Truth: Edison invented the first commercially practical electrical light bulb, the key to which was its 'long-life' filament.

"So, as to the 'coupling' effect of suspension cones: They actually act as a mechanism that decouples the device they're supporting from the surface it rests on, thereby preventing vibration from being fed back into the device. This is accomplished by setting up an impedance mismatch between the vibrating surface and the supported item via the small surface area of the point of the cone. Very little force can be transferred into the supported component through the very small contact point of the cone. Experiment: Try to push a box of canned goods with the tip of your finger (the point of the cone) vs your entire hand (the normal surface contact area of the supported device).

"As for suspension feet—pods, Sorbothane, etc.—these are hardly magic cure-all devices. They're simply components through which a 'spring system' is set up. A fair analogy is the shock-absorber system on a car. Such a system must be properly loaded in order to function efficiently: too light a load and the system doesn't function properly, too heavy a load and it will also fail to work. Imagine putting a set of Volkswagen shocks on a Cadillac, or a set of Cadillac shocks on a VW!

"The same is true of Sorbothane, et al. When using these devices, some cut-and-try experimentation is required. For example, my rather large CD player sits on three 2"-diameter Sorbothane hemispheres, with two 5-lb ingots of plumber's lead atop the player—just about the right load for the Sorbothane beneath to work its best. Happy listening, J-10!"

Thanks for your observations, Paul. And speaking of cones, however they work, I picked up on a cheapie from the Audio Asylum's Tweak forum, posted by one "Jelly-Roll Mozart." (I would have thought a Linzertorte more to the point!) He suggested using as footers the pyramidal lead sinkers typically found in a fisherman's tackle box! He cuts off the brass eye loops, cleans up the tops with medium-grit sandpaper, uses a straight-edge to make sure they're all the same height, and under the equipment they go. The results, he reports, are just "dandy." To me, it sounds...fishy. [bada-BING]

Speaking of big feet (he said, gazing balefully at his own size 11½ dogs), check out North Creek Music for Big Brass Toes. They're machined from 3/8" solid brass with a "massive 3/8-16 thread," a sharp point at one end, and a "hemisphere" at the other. The lock nut and nylon compression washer sit in the middle of the shaft. The pointy end is meant to pierce carpet or give a "firm footing" on concrete or other surfaces, "whilst the rounded end is for hardwood floors," it is explained. Overall length is 2¾" (70mm)—nearly an inch longer than conventional spikes. Each Toe comes with a heavy-duty ½" steel threaded insert with a 10mm hex-drive flange. Big Brass Toes are custom-made for North Creek in the US, a set of four costing a "Fine Tunes"-friendly $18.

Doubt that all this tweakin' is worth the effort? Here's some fine feedback from audio worthy John Everhart (jmever@aol.com):

"J-10, I took your advice and picked up some cleaned sand and #7 lead shot. I mixed the two per your e-mail. Before the mixture, the welded rack had a ting when rapped; after, it had a thud. I could not believe my ears. It was if someone turned the bass volume up, and the soundstage was wider and deeper than I ever heard—improvements that equal a $3000-$4000 upgrade, in my opinion. Thank you for your help. I hope to meet you in the halls of the Hilton in New York, as I will attend this year's Stereophile show. Thanks again. Looking forward to more 'Fine Tunes' articles!"

Hey, John, no problem, and thanks for sharing your experience and kind remarks.

Finally, reader Cyrus Won zipped me an e-mail worth sharing. He makes a different "point" about footering:

"I found light-duty cargo belts at Home Depot ($4/pair and rated to carry 50 lbs) and ended up threading them around the side horizontal supports of my steel equipment rack. I hung my components on the belts off the side supports immediately above them rather than putting them on the shelves. I got the best results when the components' bottom plates rested directly on the belts (making sure that no vent holes were covered). I thought the improvements in sound were easily discernible. At this cost, anyone with a suitable rack should try this tweak. The greatest gain is with a mechanical device (CD or DVD player), but it also works on preamps. Of course, you cannot hang whatever sits on the top shelf. Just make sure your equipment isn't too heavy for the strap! (I left my shelves in place, with the components suspended above them, just in case the straps should slip.)"

Thanks, Cyrus—a very interesting home-brew swing at an Arcici Suspense Rack!

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