GEAR:
Gizmos that make sure you hear only good vibrations
Simple steps can cut down on rattle and improve sound
By Fred Kaplan
Vibrations are the plague
of a hi-fi.
This is a gloomy paradox. A
hi-fi system reproduces the sound of music in the home. Sound
is nothing more than waves of vibration. There's something despairing,
then, to the declaration that vibration (the essence of music)
debilitates a hi-fi (the carrier of music). The solution is to
ferret out the unwanted vibrations from the essential ones.
The good news is that there
are nifty little devices that do just that and aren't very expensive.
Here's the problem. When music
blasts from your speakers, the vibrations hit not only your ears
(that's how you hear it) but also your stereo system. The damage
occurs in two ways.
First, a speaker's tweeters
and woofers move when they're pumping out sound, and these motions
literally rock the speaker box that encases them. When the speaker
box goes wobbly, the bass gets flabby, high frequencies (such
as cymbals) lose their crispness, and musical details are muddied.
Second, the circuits inside
your CD player and amplifier transmit the audio signals from the
disc you're spinning, first as digital bits, then as analog waveforms.
However, vibrations in your room (such as those coming from your
speakers, wobbly or not) are also transmitted through these circuits,
adding jitter to the bits and distortion to the waveforms.
In other words, the extraneous
vibrations overlap and interfere with the musical vibrations,
resulting, again in a flabbier, duller, blurrier sound. It's not
''distortion'' in the usual sense; you don't hear static or fuzz.
It's an obscuring distortion: You don't hear all the music on
your disc.
The tasks, then, are to keep
your speakers from wobbling and to drain or absorb the vibrations
out of your CD player and amplifier.
The solution with the speakers
is to nail them to the ground - not literally nail them (though,
if that's practical, it's a good idea). Many floor-standing speakers
have three or four holes at the bottom of their base and come
with little spikes that screw into them. So do many speaker stands
(for holding bookshelf-size speakers).
Spiking the speaker to the
floor minimizes wobbling and drains the mechanical vibrations
out of the box, into the floor. Bass is tighter, cymbals are sizzlier,
you hear more deeply into the music - clearer rhythms, harmonies,
countermelody lines.
The same principle goes for
the electronics. If possible, put them on a dedicated multishelf
audio stand made of wood or a more exotic material. Some of these
stands have spikes at the bottom of their legs that couple the
entire stand to the floor.
However, amps and CD players
can still rattle on their individual shelves. So several audio-accessory
companies make devices - vibration-transmitting cones, vibration-isolating
platforms, and vibrating-absorbing feet - that you place between
a component and the shelf.
These various companies have
various philosophies on how to solve the problem. Black Diamond
Racing, in Milwaukee, makes cones out of carbon fiber, a material
both light and rigid. Bright Star, in Newbury Park, Calif., makes
Sorbothane feet and sand-filled platform boxes.
The most cost-effective devices
that I've run across are made by a two-man outfit in Upper Marlboro,
Md., called Mapleshade, which also produces superb-sounding compact
discs. The Mapleshade Surefoot Conepoints (a set of three costs
$3 are made of brass. Place three of them under a component, in
a triangular formation, with the points down, and the improvement
is clear.
A heavier version, aptly called
Heavyfoot Conepoints (three for $65), yields extra benefits in
bass and dynamics. The difference is not subtle.
You can strip away another
veil by mounting the conepoints on a maple platform ($50 to $75,
depending on size), a thick, heavy slab of maplewood that absorbs
vibrations coming from the floor.
As a final step, put four IsoBlocks
- small rubber-cork squares - under the corner of the maple platform
($24 per set).
If you stack components on
top of one another, IsoBlocks are a good way to separate them.
Otherwise, vibrations cascade from one piece of gear to the other
and back again, like some audio venereal disease.
Finally, all these isolation
devices are useful, though to a lesser extent, with DVD players.
The picture is slightly sharpened, especially in scenes in which
the camera moves.
Audiophiles are often laughed
at for indulging in these sorts of products: audioproducts for geeks.
But do this. Go to the hardware store and buy a half-dozen
'acorn nuts,'' small brass semicircles. Place them under your
electronics, three per component, flat side up, and you'll get
a taste - a proof of principle - of the clarity that you've been
missing.
