QUOTE (bassman454)
voltage drop is a lot more of a problem when u only have 12 volts... at 12 volts a drop of 1 volt is pretty significant where at welding voltages etc.. one volt drop wont matter much.. i wouldn't try to start a car off 8 guage cable when the battery is in the boot.. and you want to try and get every bit of charge from the alternator.. specially when runnign a stereo
Well, welders are not that much better off than cars. A lot of adjustable output welders have a range down to 20 volts and most welders work only in dc. Voltage drop is an issue for welders as well which is why they use large cables in the first place. The cable sizing takes into account enough to minimize vd.
The americans worked out formula's for calculating cable size for car stereo years ago. But it was all a bit useless because of the availability and cost of cables. You would use the calculator and determine a size such as 7 or 6 guage, but try to buy those sizes? and why bother when 4 guage is only 5 bucks a meter?
After a while, people assumed that 4 guage was the norm with out realising it is twice as big as needed for the average multi amp system and started going up a size "just to be sure" when the original standard was uped a size of two already "just to be sure"
You know, when I was in the overhead power line industry, it was a bit of a joke going around about car stereo nuts running industrial sized power cable in their cars.
I used to run 8 guage in my system (only 200 watts rms back then) because I worked out the correct cable size for the system, then went up 2 sizes "just to be sure" then upgraded it to 4 guage only because I was picked on in install scoring because the judges didnt know any better.
Oh, and why is it that we insist on these huge power cables to connect to our amps, but we only use little cables to connect our amps to the speakers?
Seems a bit silly to me to want to connect 4 guage power cable to our amps for power and only 16-12 guage cables to our speakers. Aren't amps approx 50% efficient?
Ah but, I only worked in the over head powerline industry/big ass power line stuff for nine years.
What would I know?