Configuration
The most common configuration for speaker wires is the "home run."
This is where most of the equipment is in a central equipment room
and each remote speaker wire runs from there to the speaker location.
Daisy-chaining the speaker wires from one room to another is not
recommended for several reasons, mainly due to the lack of
flexibility this configuration affords.
Whether the wires run directly to the speakers or another place in
the room depends on the presence or absence of local volume controls;
local sources; and, of course, whether the speakers are built-in or
freestanding.
Built-in SpeakersConsult with the manufacturer on the proper baffle specifications;
One or two two-by-fours between the wall studs might make a big
difference in the sound quality. Note that speakers mounted in the
ceiling don't provide the best stereo separation.
Be sure to use weatherized speakers anyplace that might have high
humidity. Cover the back of the speaker if there will be insulation
behind it. Finally, heavy cloth coverings may degrade the speakers'
sound.
Local Volume ControlsAs equipment gets more capable and less expensive, fewer
installations are using local volume controls. If you do, be sure to
use the auto-transformer type (as opposed to the L-pad type) to
maintain proper impedance match with the amplifier. You should have
local volume controls on all speakers that share an amplifier.
If you have a local volume control, the speaker wires will run to
this control first, then to the speakers.
Local SourcesYou may wish to provide for local audio sources. This allows a
television or stereo in the room to use the built-in speakers. One
method of providing for local sources is with a manual switch.
Another is with an automatic switch that switches the speakers to the
local source when present. Refer to the Figure.
In either case you will need some wall-mount jacks to connect to
the local source. The speaker wires will go to the volume control
first, then to the manual or automatic switch, then to the speakers.
CablingSpeaker wire is commonly 16 gauge stranded twisted pair. Larger for
very long runs. The twist helps minimize noise pickup. Do not run
audio wiring closer than two feet to AC wiring, unless crossing it,
cross it at a 90 angle.
Join wires with high quality crimp connectors, never wire nuts.
Wall mount speaker jacks should be binding posts or banana jacks.
MiscellaneousAudio wiring should be installed after electrical, HVAC, and plumbing
is installed. It should be tested immediately after the sheetrock is
up, when it's much easier to fix.
Maintain speaker polarity from amp to speaker or the bass response
will suffer.
You may want to run line level audio back to the equipment room;
For a microphone in a "public" room, for instance. Use 22 gauge
shielded twisted pair and RCA connectors.
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