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Nuts&Bolts<br />
Diagram of <strong>the</strong> UHF platform atop a Hitachi <strong>Ultra</strong>vision television set. The<br />
front (at left) is held up by three stick-on (SSKA) Superspikes. At <strong>the</strong> rear<br />
are four SSKQ Superspikes, slightly angled.<br />
itself would decouple <strong>the</strong> speaker acoustically,<br />
while anchoring it mechanically<br />
so that it couldn’t move. The flat bottom<br />
of <strong>the</strong> Superspike structure would leave<br />
no mark.<br />
Because of <strong>the</strong> two surfaces we had<br />
to couple <strong>the</strong> platform to (<strong>the</strong> front bezel<br />
and <strong>the</strong> sloping rear shell), we used two<br />
different Superspike models (<strong>the</strong>re are<br />
six variants in all). At <strong>the</strong> front we used<br />
three of <strong>the</strong> stick-on models, if only<br />
because <strong>the</strong>y come in sets of three.<br />
Because <strong>the</strong>y’re so short, <strong>the</strong>y wouldn’t<br />
raise <strong>the</strong> front of our platform unduly.<br />
For <strong>the</strong> rear of <strong>the</strong> platform, we used one<br />
of <strong>the</strong> <strong>version</strong>s with a threaded shank like<br />
<strong>the</strong> one shown on <strong>the</strong> previous page (<strong>the</strong><br />
size didn’t actually matter, but we chose<br />
<strong>the</strong> quarter inch <strong>version</strong>, since drill bits<br />
of that size are so commonly available).<br />
We drilled holes in our shelf, so that we<br />
could friction-fit <strong>the</strong> shanks into <strong>the</strong>m.<br />
Note that where you put <strong>the</strong> rear<br />
Superspikes will determine <strong>the</strong> forward<br />
tilt of <strong>the</strong> platform, if any. Put <strong>the</strong>m<br />
closer to <strong>the</strong> front of <strong>the</strong> shelf, and you<br />
can make <strong>the</strong> platform tilt down somewhat.<br />
That’s convenient if you have low<br />
seats close to <strong>the</strong> TV, because you can<br />
still keep <strong>the</strong> centre speaker pointing<br />
toward you. Put <strong>the</strong> Superspikes too far<br />
forward, however, and <strong>the</strong> platform can<br />
tip backward. With some TV sets, you<br />
may need to bolt ano<strong>the</strong>r piece of wood,<br />
such as a narrower shelf, underneath <strong>the</strong><br />
rear part of <strong>the</strong> platform. That was not<br />
necessary with our Hitachi, but adding<br />
an extra piece could have given us more<br />
forward tilt if we had desired.<br />
The only really tricky part is drilling<br />
56 ULTRA HIGH FIDELITY <strong>Magazine</strong><br />
<strong>the</strong> holes in <strong>the</strong> rear of <strong>the</strong> unit. The<br />
Superspikes must be as close as possible<br />
to being perpendicular to <strong>the</strong> surface<br />
below. That means <strong>the</strong> rear holes we<br />
drilled had to be angled. It’s important<br />
to get this close to right, because if you<br />
tilt <strong>the</strong> Superspike too much its two<br />
internal parts will touch, and it will be<br />
ineffective. A protractor can let you get<br />
this exactly right, though it's possible<br />
to gauge <strong>the</strong> angle by eye if <strong>the</strong> tilt is<br />
not too pronounced. To protect <strong>the</strong> TV<br />
casing’s surface, we added <strong>the</strong> included<br />
adhesive felt pads to <strong>the</strong> bottoms of <strong>the</strong><br />
Superspikes.<br />
The platform was now a perfect fit.<br />
We saw that it could not slide forward,<br />
because <strong>the</strong> rear Superspikes would prevent<br />
that. It could, however, certainly<br />
slide backward. To prevent that, we<br />
purchased a pair of inexpensive stick-on<br />
doo-dads and placed <strong>the</strong>m behind two<br />
of <strong>the</strong> four rear Superspikes, to prevent<br />
<strong>the</strong> platform from moving back (see <strong>the</strong><br />
photo below). Our dood-dads were towel<br />
holders, as it happens, but one of those<br />
ubiquitous adhesive hooks will work fine<br />
too.<br />
Of course <strong>the</strong> speaker needs to be<br />
stabilized as well. We held it onto our<br />
platform using copious amounts of<br />
Audio-Tak, pressing <strong>the</strong> speaker down<br />
on it hard. Note that if you use more<br />
of it at <strong>the</strong> rear than at <strong>the</strong> front, you<br />
can increase <strong>the</strong> speaker’s forward tilt<br />
slightly.<br />
All that was now needed was to rebalance<br />
<strong>the</strong> speaker volume, which we did by<br />
placing an omnidirectional microphone<br />
at viewer position, and asking our Moon<br />
Attraction processor to take care of this<br />
little task for us (see <strong>the</strong> extensive review<br />
section in this issue).<br />
The resulting performance was<br />
excellent. The balance among <strong>the</strong> five<br />
speakers was far better than we could get<br />
with <strong>the</strong> lower front position, and <strong>the</strong>re<br />
was no sign of rattling even when we ran<br />
<strong>the</strong> biggest of <strong>the</strong> speakers at high level.<br />
Slapping <strong>the</strong> speaker hard did not elicit<br />
any ringing from <strong>the</strong> TV. Even a large<br />
speaker, such as <strong>the</strong> Thiel or <strong>the</strong> ProAc<br />
reviewed in this issue, felt reassuringly<br />
steady.<br />
Shielding<br />
It is common to look for “shielded”<br />
video speakers, ones designed not to<br />
have a strong magnetic field that can<br />
upset a direct-view TV tube. Shielding<br />
can be accomplished with an internal<br />
metal cage, or — much more commonly<br />
— with added magnets intended<br />
to cancel <strong>the</strong> woofer’s own magnetic<br />
field. Because both techniques result in<br />
a performance hit (and possibly because<br />
<strong>the</strong>y’re expensive), shielding is often<br />
minimal.<br />
The platform may add just enough<br />
distance so that even an unshielded<br />
speaker will not interfere with a directview<br />
TV. If it doesn’t, it may be possible<br />
ei<strong>the</strong>r to place a steel sheet under <strong>the</strong><br />
speaker (it must be magnetic, not stainless<br />
or some o<strong>the</strong>r non-magnetic alloy),<br />
or else to double up on <strong>the</strong> shelves to<br />
get more distance. You’ll need to experiment,<br />
because some sets need more<br />
shielding than o<strong>the</strong>rs.<br />
We were prepared to make this a<br />
complex project, but as it turned out we<br />
didn’t need to. Anyone who has done<br />
even <strong>the</strong> most minor home maintenance<br />
can probably build a platform just like<br />
ours in an hour or two, possibly including<br />
<strong>the</strong> shopping time. You’ll be happy<br />
you did.