Everybody knows that you need to have the speakers of your home
theater connected to an AV
Receiver, regardless of whether it was purchased separately or that
it came with the speakers as an all-in-one product. It’s also pretty much
understood that you put the Left front speaker and the Right front speaker (so
as to have stereo) and the center speaker (a.k.a., center channel) between
them. That leaves the two surround speakers (Left and Right) which need to go
as their name implies on either side of the room near the back so that they’re
even with where the people who are going to be watching are sitting (i.e., on a
couch or lounging chairs, etc.). As far
as the subwoofer goes there’s no worries — that’s because, unlike the other
speakers, a subwoofer’s sound is omnidirectional and so it can be placed near a
wall or behind a couch, etc. without concern. And as far as where the people
are sitting, that is dictated by where the TV
is — and you can bet a BIG
SCREEN TV will get a lot of people to watch. That also dictates
where the speakers will be placed relative to the TV and to the people.
But what’s not so obvious is that all of these speakers need to
be calibrated against each other so that their sound blends together as
necessary (for example, when there’s dialogue) or steps back to let surround
effects take over (for example, when there’s an explosion in the movie). You can’t just turn the volume up or down
because that affects all the speakers together; what’s needed is to calibrate
the speakers to each other and to the room they are playing in. This will not
only take care of the problem but will also tailor the sound to the particular
environment — your home — so as to make it more suitable for you.
DOING THE CALIBRATION AUTOMATICALLY
The basis for this is for the audio receiver to put out a series
of pulses/sounds from each speaker and so adjust the individual audio streams
based on their location to those who are listening. Modern AV
Receivers have this calibration system built in. All you have to do
(besides follow the instructions provided on the receiver’s faceplate or on the
TV
if the receiver has a connected interface to view) is place the included
microphone at the listening position (i.e., your favorite seat on the couch,
etc.), plug it into the receiver and activate the system. To do it properly
it’s important that any surface sounds be eliminated, so if the street outside
is particularly noisy or the nearby refrigerator or microwave is making a din,
just wait a bit before going ahead. You turn on the system and leave the area
and come back when it’s done (i.e., it’s quiet). Then you watch as the AV
Receiver takes care of all the calculations and processes and just
has you accepting a few decisions it’s made (or you tweaking them if you
prefer). That’s it.
DOING THE CALIBRATION MANUALLY
On the chance that you just like to do things yourself because
you don’t think much of somebody else’s idea of how digital tech should work —
then doing the calibration yourself is the answer. You’ll need a sound pressure
level meter (SPL) and a small tripod that you can place it on. The procedure is
a bit too involved to go into here; the basic steps are to first place the
speakers in the correct position in the viewing area, set the receiver as to
the size of the speakers and to put out the tones (pink noise, is what it is
called) moving clockwise around the speakers. You’ll use the meter to adjust
the levels of each speaker as well as the subwoofer.
There are audio discs that will “talk” you through this and they are commercial
available and not expensive either. The main thing is to read up on doing this
based on your system and speaker set (check the receiver’s manual too) and then
take your time. Of course if you have a professional installation done to place
your speakers for you (for example, using the services of a company like Just One Touch),
then all this will be taken care of as a matter of course.
Calibration your home theater’s audio is the best thing you can
do for yourself when it comes to the sound that you’ll be hearing.