Originally Posted by xtremerevolution
I used the 1000.1 as an example. Obviously if someone knows their amplifier has a different efficiency, it is irrelevant. Your particular amp is one of the best amps on the market and does in no way represent the vast majority of amps that people will be buying. The concepts I pointed out still apply. Also, fuse ratings are not by any means a limit of the amp'* current draw as they are only there for short circuit protection. What I said still holds true. If you know your amp'* efficiency, do the math and you'll figure out what it will draw under full load.
As far as CCA, I cannot tell you how many headaches it gave me in my car. I literally wasted 4 hours of my time and $100 of money I could barely afford replacing a starter only to find out that the CCA I had wired to my block ground had SEVERED from corrosion an inch away from the terminal. Yes, there was 2" of 1/0 gauge CCA clamped in the terminal, and I riped it off like a sheet of paper when I wiggled the wire. It is absolutely horrible to use in an engine bay where it will be exposed to heat fluctuations and moisture. You might have a different opinion, but the simple fact is that its pure garbage in that environment. It corrodes very easily and loses voltage significantly faster than copper. In fact, 1/0 gauge CCA is slightly worse than 2 gauge copper from the research I've done, only copper doesn't corrode as quickly.
Trunk is a different story of course, but my personal preference is to stay away from it.
Ask John, there'* a reason this wire starts electrical fire in houses and consequential lawsuits. Not in my car. Its not just about the power handling man.
Sorry X, your concept is far from correct. This is basic ohms law stuff here
Watts = Amps x Volts
Volts = Watts / Amps
Amps = Watts / Volts
However, those are rough estimates that would get you in the ballpark, if you want to get more precise results then you'd have to do some more calculations/measurements.
To find your actual wattage you would need to first measure the ac voltage at the speaker terminal on your amp, let'* say it'* 50. Then you'd multiply that by itself and would end up with 2500. Divide that by the impedance of the speaker connected to that terminal, let'* say it'* 2ohms, you'd end up with 1250.....this is the max output which we all know is about as useful as using tongs to eat rice....so to find the rms you simply divide that number by 2 and you'd end up with 625rms.
Now to find out the amperage draw, measure dc voltage at the amps power/ground terminals, let'* say it'* 14....Divide the wattage, 625, by the voltage, 14, you'd end up with 44.6a MAX CURRENT IF PLAYING A TEST TONE AND WITHOUT CONSIDERING THE AMPLIFIERS EFFICIENCY. To factor in the amps efficiency and to find out it'* consumption on music you would need to multiply that number by 1.5 (assuming the amp is 50% effecient...if it'* 80% efficient then you'd multiply by 1.2) and then divide that by 3 since playing music, which is dynamic in nature, uses a third of the power it takes to play a test tone. The result is 22.3a current draw on average, playing music at full tilt.
I don't know anyone who drives around playing test tones at full tilt all day, how about you?
As for CCA, it'* a matter of affordability and personal preference I guess. I would prefer to have the superior conductor for my power wire but I refuse to pay $3.50/ft. and up for OFC wire, it ain't happening! And since I've been installing systems for 19yrs and have NEVER paid for the pricey stuff and have not had a single power wire failure that whole time, I have no reason to do things any different now just because the marketing geniuses at these companies have found the latest and greatest way to cash in on the fear they infect us with as a result of their horrendously overstated and often deceiving explanations and information about their product.
I'm not new to this, i've been at it for nearly 2 decades