"Ecnerwal" wrote in message
...
In article ,

Harold and Susan Vordos wrote:
thinking I may go to a 600 watt/channel model. ...
Considering the additional information I've provided, would you still
recommend using the #14 wire? ...

Bob Engelhardt wrote:
Never mind what I said before, I definitely think that you would not be
happy with anything less than #10 wire. (How's that for not answering
the question?)

Oh, heck, run some 4/0 welding cables...Or just put the conduit to hold
them in place, slap the speaker on one end of it, and a speaker grille
on the far end ;-)

Actually, I think the earlier suggestion to run shielded signal cables
and place an amplifier near the far-away speakers is the best solution
for long runs.

Your long run is "about 120 feet". Here's the resistance for 120 feet of
copper wire, and the effect on 600 watts into 8 ohms. 600 watts into 8
ohms is 69.76 volts at 8.6 amps. The volts are the voltage drop for 120
feet of wire at that amperage, and the watts are the power dropped in
the wire, out of 600 watts. I suppose you should double all this since
the wire is to and fro, or 240 feet total.

14ga = 0.3 ohms 2.66 volts 23 watts
12ga = 0.2 1.67 15
10ga = 0.12 1.05 9
8ga = 0.07 0.66 5.6
6ga = 0.05 0.41 3.5
4ga = 0.03 0.26 2.2
4/0 = 0.006 0.05 0.4

So if you really want to satisfy the criteria (someone mentioned, don't
know how much it matters, personally) that you should keep speaker wire
resistance to 0.1 ohms, you'd need to go to 6ga for the 120 foot (240
feet round-trip) run. And you'll have to run back to the house to change
the volume. If you put in a sheilded signal cable, carrying essentially
no power, you can use tiny wire, and you'd have direct volume control in
the shop, where those speakers are (if I understand your setup
correctly).

Chuckle! Yeah, I could do that, but if you've priced Mc amplifiers (I'll
settle for nothing less), you'll understand how cheap large wire looks to
me.

The likelihood of me using anywhere near even 200 watts in the shop is
relatively remote. I can fill a large (*very large*) room with a few watts.
It's very easy for me to overwhelm the loudest of noises with what I have
now, but I'd like the additional power in reserve for heavy passages at
moderate volume. Think 1812 Overture, Carmina Burana, or Toccata & Fugue
in D Minor. The chance of using the 600 continuously is not very
realistic. By the time I'm pulling 300 watts continuous it's not a very
friendly environment. And I wonder why I have tinnitus? g

I recall an experience of many years ago,when I was running a smaller amp
(Mc 2105, two channels @ 105 watts/channel). I had installed some cheap
speakers in the shop and wanted to control the volume. on location. I
knew the output was severe, but was talking with a typical bonehead that
works in a supply store that isn't really in tune with output, apparently.
He provided me with a pair of what I think were called L pads. Rheostats,
more or less, but I'm not sure. I told him that I'd likely smoke them
quite fast, considering the amp had a lot more output than the rating, which
I recall to be 20 watts. He looked at me as if I didn't understand the
least thing about sound gear and told me that I simply don't have enough
power to hurt them, that they were intended to be used exactly as I desired.
Took them home, got them in installed in a couple of handy boxes on the
wall, turned on the stereo and the smoke got out almost instantly.

After much inquiring from various sources, I ended up with a pair of what
must be autoformers, made to be used exactly as I desire, equipped with a
faceplate and several positions nicely marked, which handled the load with
no problems, each of which mounted in the same boxes. I'll use that same
setup again, the only difference being the speakers will be different. I
was fortunate to see them for sale in the paper, being sold because the
cabinets were trash, but the speakers are fine. Price was right, especially
when I've seen the 375 drivers selling for a grand each. I paid just more
than half that for the set of speakers. Hey, they're for the shop.
Cabinets can be ugly. My typical practice is to set volume slightly
higher than I'd like it to be, then control in the shop. I can shut it
right off if the phone rings, or get above the sound of my whining lathe
taking roughing cuts in stainless. It worked fine for years, so I'm hoping
it will here in our new digs, too.

Thanks for the great input. Right now I'm still thinking 10 ga, but
certainly nothing smaller. From the figures provided, it looks like things
get right out of control with smaller than 12 gage wire.

Harold