"Bob Urz" wrote in message
...
PrecisionMachinisT wrote:
"Bob Urz" wrote in message
...
PrecisionMachinisT wrote:
"Fiber Optic" wrote in message
news:MXJHc.894$sj.412@lakeread02...
A contractor is quoting me $100 per location for running 16 gauge
audio
wiring in my new home which is being built by the main contractor. A
"location" is basically a single room, with two speaker locations, a
volume control location, and wiring all locations to one central
location.
Only the wiring is included, not the volume control knobs.
I have 12 locations which turns out to be $1200.
Does this sound reasonable?
I need to ask the contractor if conduit can be installed as well for
future wiring changes/updates. I'm hoping this does not affect the
cost
too much.
Any help appreciated.
Chris
Suggest using 70.7v wiring, home run.....22 ga will pass more total
watts
that way.
70 volt wiring is commonly used in distributed sound systems in business
and churches. It is NOT commonly used in home systems. Mainly because
the home theater type amps a lot of these use do NOT have 70 volt
speaker outputs. With the proper commercial type 70 v output amps it
could be done.
You are correct, you can use a smaller gauge wire on a 70 volt type
system. But the amps on the front end and distribution may cost you
more. Of course with 12 locations it could skew the equation.
Is there a speaker in the toilet lid? 
Bob,
You simply match a transformer at the amplifier output to bump the 8 ohm
up
to a 70v line distribution level.
It takes no special gear except the addition of the above mentioned
transformer at the amplifier, and impedance matching transformers at
each
speaker location--and the speakers are as commoin as dirt.
A lot of home type amplifiers don't like inductive transformer loads.
(converting a non 70 volt unit to 70 volt using a output transformer)
Its not uncommon to blow the output stage up doing this. Sometimes it
will work, sometimes its a ticking bomb. And if you just blew your new
amp doing this, it could void the warranty. Quality of the transformer
is critical also. Some cheaper transformers behave like shorts at low
frequencies and higher power levels. You have to also match the power
rating of the transformer to the output rating of the amplifier to keep
the turns ratio thing in line.
Step up--step down.....
Our residence has a mix of 8 ohm, 25.5v and 70.7 v distribution covering
nearly 9 acres total,
I would call that a ranch, not a residence
audible from any point on the property--the amplifiers
being the lowly bogen c20, the right of way also happening to be along a
major interstate.
A bogan c20 is a commercial amp that was designed for 70 volt use with
an internal output transformer. Its not exactly hi fi, but it will make
noise.
Now, I dont give a rats ass as to what might be the latest greatest on
the
market, I just suggested installing a system that is inexpensive and
expandable and which has been proven through close to a centuries worth
of
practical application in commercial use--after all, it wasnt me that
came up
with the notion of feeding audio to some 12 rooms, this was in fact the
original posters idea, although I have done exactly the same thing
myself,
and rather successfully, IMO
12 rooms in a single family residence is a definite upscale install in
my book.
On the other hand, I could have suggested gold plated conductors be used
instead......at 6 gage no less......
Many people buy into welding cable sized oxygen free wire as big as
welding cable for $2+ a foot schmuck. For most average systems, 16 to 18
gauge is fine. (NEC fire rated of course to stay legal)
Sheesh, your no fun tonite........
We could argue this :
A lot of home type amplifiers don't like inductive transformer loads.
(converting a non 70 volt unit to 70 volt using a output transformer)
Till we are both blue in the face.....
====
But Im a good troll, and some good and some bad points both have been
brought out from all this, and so Im just about done.....
====
brag
Nobody asked what I gots setup for sound down here in the basement, but its
250 watts per channel, and beings its just under 1600sf down here, its still
a bit lacking in headroom when at normal listening levels......this all
being rack mounted stuff and with the speakers coming surplus from a local
baseball stadium.......vintage Altec and Electrovoice......
/brag
Cheers, and do carry on....
G
--
SVL