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Getting the Most from Your Wireless Speaker System
Introduction
A home entertainment system in the true sense
of the term, offering vibrant, high resolution
pictures and immersive, multiple channel sound
is, nowadays, within the reach of the typical
domestic consumer in the United Kingdom. Pictures,
delivered by a flat panel, LCD ("Liquid Crystal
Display"), or Plasma, or even a projector,
are usually straightforward to accommodate,
but sound, digital surround sound, to be precise,
may present more of a problem.
A typical 5.1 channel, digital surround system
requires 5 main loudspeakers arranged as centre,
front left and right, and rear left and right,
plus a subwoofer for low frequency, bass effects.
Wired rear speakers inevitably involve long
runs of speaker wire, and an increasingly
popular option is the use of wireless rear
speakers.
"Wireless", here, means that the speakers
require no physical connection to an A/V receiver,
and instead receive signals from a small transmitter
attached to that receiver (or, indeed, any
other compatible audio device). In a home
entertainment context, even "wireless" rear
speakers do in fact require a mains power
wire; battery operated speakers are available,
but these are better suited in terms of output
power, to receiving signals from a PC or an
MP3 or other media player.
Music lovers can of course, transmit signals
from a stereo HiFi, CD, or MP3, player to
wireless speakers throughout, and beyond,
the home (including outdoors, at a range of
up to 150' in some cases) without the need
for wires, extenders, etc., and without having
to lug a boom box from place to place. A similar
comment is true of PC users, who can transmit
signals to a 5.1, 6.1, or 7.1 channel, wireless,
digital surround sound system, for realistic,
360° sound from DVD films, CD, or MP3, music,
or video games.
Wireless Home Entertainment Speakers
Truly wireless audio is the Holy Grail of
consumer electronics, not only because of
the mains power requirements, but also because
lost or jumbled data packets result in a loss
of audio quality. Wireless technology nevertheless
makes sense in the context of home entertainment
systems, because it is both convenient, and
affordable.
Wireless speakers usually operate via IR ("Infrared")
or RF ("Radio Frequency"). Infrared requires
direct "line of sight" between a transmitter
and a receiver, and may therefore be susceptible
to interference, and signal drop-out, caused
by intervening objects, or people walking
between devices. Radio frequency signals,
on the other hand, are able to permeate walls,
floors, etc., and the latest RF wireless speaker
systems typically employ higher quality transmitters,
and receivers, than their IR counterparts.
RF wireless speakers do, however, run the
risk of interference from, from mobile 'phones,
and other electronic devices, so it is worth
considering exactly which devices you have,
in your household, before opting for wireless
speakers of this type.
Wireless home entertainment speakers as a
whole, operate either in the 900MHz or the
2.4GHz frequency bands, with a range typically
between 100' and 300', and allow data to be
transferred between transmitter and receiver
at up to 1.5Mbps ("Megabits per second") in
line with the latest IEEE ("Institute of Electrical
and Electronics Engineers") 802.11 wireless
networking standards, which is a significant
improvement on the low transmission rates,
and poor quality, of some earlier models.
Indeed, one of the major advantages of wireless
speakers is that no speaker wires, or Ethernet
cable, needs to be pulled through walls; a
costly and troublesome operation, at the best
of times, and they can be accessed from different
locations, by different devices, so do not
become obsolete as technology elsewhere evolves.
Wireless home entertainment speakers may be
supplied as part of an HTiB "Home Theatre
in a Box" solution, which should therefore
include a set of speakers, matched for tone
or "timbre", throughout, together with configuration
and control features for wireless rear channels,
and speakers. With regard to the placement
of wireless rear speakers, the ideal position
is slightly behind (but not directly behind)
the listening position, at just above ear
height, and directed out across the listening
space, rather than down towards the listener(s).
Many film soundtracks are optimised for the
placement of surround speakers in just this
position. Alternatively, you can choose separate
wireless speakers, of an appropriate size;
"bookshelf" speakers, which, as the name suggests
can be positioned on shelving or furniture,
are popular to complete your digital surround
sound system, or to be located in a kitchen,
bedroom, or elsewhere, to play music.
It is however, worth exploring the options
available, with regard to speaker configuration,
on your A/V receiver. This should allow you
to select whether your wireless rear speakers
are large; typically 6", or more, in diameter,
for the largest driver, or small, and to input
the distance from the speakers to the listener.
This latter figure may be the actual distance,
in feet, or the time required for sound to
travel that distance, in milliseconds (ms).
Sound travels at just over 1,100 feet per
second, at sea level and therefore, as a rule
of thumb, requires roughly 1ms to travel 1
foot.
You can, of course, also enjoy the benefits
of a wireless speaker system in a garage,
or a garden if it is within range of a transmitter,
and some speakers nowadays, are solar powered,
and so can be operated without mains power
per se, during fine weather. Most wireless
speakers will work well outdoors, provided
that the weather is not too inclement, but
if you are intending to use them outdoors
often, or say near a swimming pool, a water-resistant
design is a wise choice.
Wireless Computer Speakers
Another popular application of wireless speakers
is in combination with a PC, or laptop computer,
where they can add an extra dimension to video
gaming, with sound reproduced on 5, 6 or 7
main loudspeakers, plus a subwoofer, situated
around the listener. The same is true if a
PC or a laptop is used for watching DVD films
and at a slightly lower level of sophistication,
even a stereo, or 2.1 channel, wireless speaker
system can be used to convey music, complete
with clear, distortion-free bass, from your
computer to the location in your home where
you want to listen.
Wireless computer speakers nowadays, lack
nothing in functionality or performance, when
compared to the wired equivalent and of course,
do not add any further wiring to your desktop.
This can be extremely economical in terms
of space, since a typical wired surround sound
system requires not only a wired connection
between a computer and each speaker, but additional
connections for a subwoofer and power, which
can result in an unsightly mass of "spaghetti"
dangling from the back of your computer if
you're not careful.
If you're planning to use wireless computer
speakers in a home office, or other small
space, remember that the "soundstage"; the
space, akin to a real stage, that you are
trying to fill with sound, is also small or
"tight", so that the output from each speaker
does not need to be very high. Too high an
output may simply overwhelm a small listening
space, as sound will bounce around the room,
especially off the ceiling, frightening the
cat, or more importantly annoying your neighbours,
whereas too low an output in a larger space,
may result in sound dissipating very quickly,
and being "lost".
Speakers may well require less output power
than you would immediately think; 10 watts
is sufficient for listening at a reasonable,
but not extreme, volume level in a typical
15' x 15' room, for example, and the smaller
the room, the less output power is required.
Nevertheless, it is the output per speaker
not the output of the system as a whole, which
some manufacturers are fond of quoting in
which you should be interested.
Bear in mind, too that the RMS, or "Root Mean
Square" power rating of any speaker should
be at least equal to the RMS power rating
of the amplifier driving that speaker. Don't
confuse this with the "peak" power rating
of a speaker, as this is a measure of the
power that is can withstand, instantaneously,
without failure. Subjecting a speaker to more
than its RMS power rating for a period of
time will, ultimately, cause it to fail mechanically.
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