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Consumer Guide to Plasma Television Anyone considering the
purchase of a plasma television should read our comprehensive
white paper. As more and more networks broadcast shows in high
definition, plasma displays have become the most sought after
high-end televisions and the field's getting crowded with options.
We take this technically complex product and discuss the technology,
recent advances, reliability, warranty and support to help you make
an informed purchase.
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Cable Television Induced "Ground Loops" Got hum? Maybe it’s not your
problem. Read why you may need to contact your cable provider.
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Glossary
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A discussion of simple solutions to common problems ranging
from bi-wiring issues to recommended warm-up tips for those idle amplifiers;
issues that can cause significant degradation to the enjoyment of your
system and the beneficial practices that eliminate them. Note that the
problems occur exponentially more frequently in systems which you have set
up for yourself than ones which we have set up for you...
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Bi-wiring (Cables, Speakers, & Amplifiers) Talk about counterintuitive. How does my amp know
how many sets of cables I’m running from it? Or my speakers how many
I’m running to them? And why would they care? The truth is they
don’t know or care. It’s the cables themselves that do. Bi-wiring is
a technique to make two sets of cables sound better for the same or
less total expenditure than a single-wire set-up. How does it work?
By removing detrimental low frequency (bass)
energy from the cables carrying the delicate voice and imaging
signal to your midrange and tweeters and, to a lesser extent,
providing a similar dedicated path to the woofer(s). There are three
ways one band of frequencies can negatively influence another in a
speaker cable: in the conductor (metal) itself, by electromagnetic
infiltration, and mechanically (physical movement).
True bi-wiring (running one set of cables from
your amp’s output terminals to a low frequency input on your
speakers and another set to a high-frequency input) eliminates all
three and should significantly increase clarity, openness and
definition in your sound. So much so that adding the two prices of
those cables and running single-wired for the resulting total price
should still sound worse. And therein lies the benefit: the
price/performance ratio improves.
What’s going on? A bi-wire ready speaker (one with
two sets of inputs) lets you move the crossover (electronically, not
physically) from inside the speaker after the speaker cable
to back at the output of the amplifier before the speaker
cable. The speaker’s separated filters will then draw only highs
down the top cable and only lows down the bottom one yielding a
substantial performance improvement in your cables. Let’s imagine a
tweeter with its filter in Chicago, a woofer with its filter in
Minneapolis and an amplifier here at Ultra Fidelis in Milwaukee. The
filters would telegraph their actions back to Milwaukee and only
highs would head south on the wire to Illinois. Likewise, only bass
would go north to the Twin Cities.
Caveats? Be careful mixing brands or philosophies
of cables. A cable with "nice highs" mated with a different one
noted for "great bass" all too often results in an unhappy marriage
which sounds less good than either one by itself. Keep all cables
the same length. Many speaker cables can be "internally bi-wired"
within one cable package and this can be a nice, cost-effective
improvement over standard termination. Just remember that, although
you have eliminated the interaction within the conductors, you have
done much less to address the other two distortions which are cured
by true bi-wiring.
Finally, while any amplifier can be used in a
bi-wire setup (there is no such thing as a "bi-wired amp" although
some kindly offer two sets of output connectors or extra long-throw
binding posts), make sure your amplifier can accommodate the
additional wire or we can terminate your two sets of cables into one
connector.
Break-in/Burn-in These terms are used to describe
the initial "coming around" of a new system or component to its
final state of wonderfulness. It is good to bear in mind that ALL
components when new are inferior in sound and picture quality to
what they will be someday so it is a mistake to evaluate new
components or systems for performance.
Play them as much as you can
at first and cut them the slack they require until they are
"matured." Some may take one playing-month to finish the process.
Remember, too, that if you don’t listen/watch for three weeks, the
system will have fallen back towards this rude, new state. Don’t
make us relate the somewhat embarrassing story of how we learned
that SpeakerCraft speakers could go from sounding rather mediocre to
become the best value in-walls we had ever encountered just by
benefit of break-in. EVERYTHING needs it.
See also "Warm-up".
Direction of Cables Why are there arrows on my wire?
Doesn’t the music know where it’s going? This is one of those dicey
ones that engineers love to argue about.
Let’s just say there are
things about the manufacture of a quality audio cable that enable a
designer of a wire product to suggest a preferred orientation of the
cable. There, everyone should be happy with that. Hard core
engineers will continue to scoff and run their arrows pointing every
which way and we’ll continue to follow the arrows because back last
time we compared, it really was better that way. Noticeably so.
As a guide for you arrow-followers, the arrows should point FROM the
earliest component in the chain (usually a source component like a
CD player) THROUGH all preamplification and amplification TO the
speakers. And yes, if you’ve been running them backwards, please see
"Break-in/Burn-in".
Phase Ah, phase. When the many
requirements are properly met, all is right with your sonic world.
One little thing is wrong, however, and it will eat at you to no
end. The short description of correct phase is that all speakers are
moving in the same direction at the same time as the original
microphones. Wow, that IS short, isn’t it? Well, it suffices
because, after you’ve bought your equipment, a lot of your Phase
Future is already determined for you. What you CAN control is the
hook-up of speakers to amplifiers which is your one big opportunity
to get it wrong.
Simply put, if your RED or
POSITIVE or PLUS (sometimes marked as a positive number on a tube
amplifier) connector on your amp is connected to your RED, etc.
terminal on your speaker on ALL channels, you will (99.99% of the
time) have correct relative phase in your system meaning all
speakers will be working in concert. Get one or more wrong, and
things go bad pretty quickly. And it’s amazing how easy it is to
mess up a multi-channel hook-up if your attention lapses.
By the way, the reason for the
parenthetic percentage hedge above is that there is the rare
amplifier which inverts what’s called absolute phase which
means that in order to follow the Law of Mimicking the Microphone
you must purposely hook up any speakers to it backwards (plus to
minus and minus to plus)! We almost hesitate to mention this rare
exception because the only time it really bears on the sound of your
system is when you are using more than one amplifier in your system
and they differ as to absolute phase, e.g. your front channels amp
does invert and your rear channels amp doesn’t or you’re bridging an
amp for your center and you don’t know which red is now positive. Be
very careful in any of these situations to get it truly right.
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Phono, Preamp Where do I plug my turntable? The reason your amplifier or
receiver doesn't have a button labeled "phono" is that there is no
phono preamp on board. Does this mean you cannot use a phonograph?
Yes. And no. Although turntable and record sales are experiencing a
boom in the last several years, they nearly became extinct about
1990. As manufacturers of audio electronics moved toward a new
market driven by "home theater", they had to cram a lot more stuff
into the same old receiver cabinet: Dolby Pro Logic and other
surround sound processing, three more channels of amplification, and
video (picture) signal switching. With only a small, and at the
time, shrinking portion of their customers listening to vinyl, they
made the decision to bump the phono preamp from the list of
"features" on your average audio preamplifier or receiver. This made
for a more cost-effective unit in a marketplace no longer demanding
phono, but what does it mean for you and me, the rest of us who do
want to play phonograph records? Like most things in life, it is
both good and bad.
Unfortunately, no matter what turntable you have, you must have a
phono preamp in your system in order to listen to records. The only
exception to this would be an ancient (and deplorable) ceramic-cartridged
turntable. If you have one of these, replace the machine with
something decent. Assuming your turntable or the one you plan to
purchase, has a magnetic cartridge of some sort, you need a phono
preamp for two reasons: The signal cut onto the record has had its
bass decreased and its treble increased and one of the functions of
a phono preamp is to undo those modifications. If the sound were cut
onto the record in a linear fashion, without the above mentioned
"equalization", the bass would eat up so much groove space that the
LP would be an SP of about 3 minutes duration. To get truly Long
Play and great sound the bass has been reduced and the treble
increased to get it above the noise in the medium (vinyl) which
tends to be predominantly in the treble. The phono preamp is where
the "re-equalization" takes place: increase the bass and reduce the
treble so the sound returns to its normal tonal balance.
The second function of the phono preamp is to additionally
amplify (make louder) the signal coming from the cartridge. Because
phono is the only sound medium wherein the "reader" (stylus, needle)
is mechanically driven by the medium (record groove), it
produces relatively less output than other media such as radio
tuners, tape machines, and CD players. The other function of the
phono preamp, therefore, is to "preamplify" the delicate sound
signal an additional step before it goes into the line preamp
section it then shares with all other input types.
So you may gather by now that if you plug your turntable into any
of the existing inputs on your new amplifier, you'll get a squeaky,
raspy, bass-shy sound that is barely audible even with the volume
almost full up. You may even have tried it. It won't work. Are you
dead in the water? No. Fortunately the boom in interest in vinyl of
recent years has brought about a new component: the outboard phono
preamp. As its name implies, it is a standalone device that is
positioned between your turntable and any non-phono input of your
amplifier in the flow of the signal. In other words, your turntable
plugs into it and it plugs into your preamp. It performs the
necessary equalization and gain to make the phono signal at its
output electrically the same as any other signal you feed into your
line preamplifier section of your system. Voila! Now anyone can play
records again.
How much, you say? The good ones start around $120 and stop
around, well let's just say you could spend the price of an
entry-level automobile on one if you were so inclined. What you get
for more money is noticeably better sound, as you'll hear what the
quality of the phono preamp contributes to your listening enjoyment.
Something in the range $120 range, plus $30-$50 for a good cable to
run from it to your preamplifier should be adequate to make you fall
in love with records again, or for the first time. You can climb
from there as your ear, turntable, system and wallet permit.
Room Acoustics Rooms tend to sound the way they
look. Small rooms have smaller, more intimate soundstages while
large rooms can support bigger images that are life-sized. If a room
has mostly hard surfaces (i.e. wood floors, glass, marble, drywall,
etc…) the sound will usually be harder, brighter and more lively but
with less image focus. By the same token, a room that is dominated
by softer materials (i.e. carpet, pillows, drapes, fabric covered
couches, acoustic ceiling tiles, etc…) will sound more quiet and
soft with less dynamics but more focus and clarity. The best rooms
tend to be somewhere in the middle of the two extremes, with a mix
of hard and soft materials.
There are also ways to improve the
sound of any room by strategically positioning the hard and soft
materials so that they help rather than hurt. A good way to start is
with the "live end – dead end" approach in which you want the
listener end of your room to be more live while the speaker end
should be more dead. Just remember that surfaces close to the
speakers should be absorptive or at least diffusive so as to prevent
strong reflections from interfering with the direct sound of the
speakers. The areas at the back end of the room can be more
reflective in order to balance out the room sound. If you follow
these guidelines, your system will sound lively and dynamic while
maintaining good image focus and a natural tonal balance.
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Speaker Positioning Chapters of books, sections of
owner’s manuals (see Vandersteen’s for a good one) and computer
programs have been written to aid in this black art of system
optimizing. If your speakers are already attached to or mounted into
the wall, you can go on to the next topic. If you have any range of
placement options at all, well, there’s no easy way to describe the
lengths to which you can go to tweak speaker placement. First, refer
to your owner’s manuals and follow any general placement
instructions as closely as you can. Absent any, most designs will
prefer a reasonable distance, say a foot minimum, between the back
of the speaker and the wall behind it. The included angle of you to
the two speakers should be roughly 60 degrees.
Now experiment by moving one
speaker at a time, with the other one off, and going back to the
listening position to check for a warm, extended, linear bass region
handing seamlessly over to a coherent, open midrange. Don’t worry
too much about the treble at this point. With your eyes closed,
listen for where the one speaker "disappears" most convincingly. Now
shut this one off and do the other one. Generally, you will want to
start with it the same distance from the wall behind as the other
speaker and move it mostly laterally.
Finally, follow any instructions
in the owner’s manual as to tilt, toe-in and the like or experiment
with these as well. You might have a (hired) friend rotate one
speaker at a time (with the other one off) slowly until you like
what you hear and then slowly tilt it back or maybe even forward,
although back is more likely.
Here’s where you can start paying
attention to the treble; listen for a sound that is neither bright
nor dull and makes you relax, makes you like what you hear and
informs you most about the recording. If you get each speaker doing
this independently, you will have guaranteed magic when you have
them both on. Plus, when you get one really right, you can typically
just match the other one to it with your eyes for rotation and a
plumb line for tilt. Trust your gut reactions during this process.
I’m sure I have customers from the late ‘70s who are still moving
the same pair of speakers around the same room looking for Nirvana
(I know Vincenzo is) and have yet to enjoy any music.
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Spikes Yes, they will look to the
disinterested friends and relatives in your life as if they were
designed specifically to eat up floors and carpets, but with the
proper treatment, they don’t and the good they do for your sound and
picture would far outweigh any such damage anyway.
If you are on
carpeting, they are a must for speakers and strongly suggested for
equipment racks, but they are almost equally beneficial on hard
surface floors. In both cases they act to usher signal-degrading
vibration away from the equipment and into the floor where it can
harmlessly dissipate. For non-carpeted applications, we sell Spike
Shoes which interface between spike and Valuable, Imported, Exotic
Floor Surface without corrupting the performance of the spike.
Warm-up See "Break-in/Burn-in".
Warm-up is
the "coming around" of a system to its daily state of wonderfulness
after not being used for a day or two. There is no known cure for
this need other than playing time, so if you feel picky today, play
something for an hour or so before you really want to pay attention.
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