Voltage drop and Electrical question

[tsenfw 10+ year member]

Have a couple of questions, tried searching but couldn't find the answers.

1.) I have an amp capable of 800watts at 2 ohms and 1200watts at 1ohm. Is running at either of these more of a draw on the battery and alternator? I'm guessing they're the same because you would have the same voltage output at the amp because there is just less resistance hence more wattage, right?

2.) When people mention a voltage drop when running an amp, where are they reading voltage? Are they using gauges on the dash through the cars factory wiring or using a voltage meter before the amp? Multimeter?

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[kurtdirt1 10+ year member]

Watts equals Volts X Amps so yes running amps @ different ohm loads for different amount of power pulls more or less current...Typically as you go lower in impedence your amp draw increases.....

 

[tsenfw 10+ year member]

uh oh, i wonder by how much that will be a factor. I'm running at approx 600+ watts at 3 ohm right now and my lights are dimming on really big bass hits.

I plan on running 1 12 at roughly 1000 watts at 1ohm I hope I'll be ok, I might have to go lower huh?

 

[kurtdirt1 10+ year member]

u mean higher...but yeah, if ur having voltage probs @ 3ohm it'll only get worse @ lower impedences

 

[tsenfw 10+ year member]

Well, how would I even measure for voltage drops?

 

[ultimate157 5,000+ posts]

get a multimeter //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

http://www.bcae1.com

 

[tsenfw 10+ year member]

hmm i don't think you can use a mutimeter to test before the amp. Most if not all multimeters have a 10 amp nonfused limit. Which means the amp will literally fry on anything more than 10 amps.

Isn't there like at least 50-100 amps going from batter/alternator to the amp? Where am I supposed to measure the voltage drop?

 

[lostdaytomorrow 10+ year member]

Measure DC Voltage at the B+ and ground on the amp terminals where the wires are plugged in. Shouldn't drop to below 13 volts.

 

[ultimate157 5,000+ posts]

hmm i don't think you can use a mutimeter to test before the amp. Most if not all multimeters have a 10 amp nonfused limit. Which means the amp will literally fry on anything more than 10 amps.
Isn't there like at least 50-100 amps going from batter/alternator to the amp? Where am I supposed to measure the voltage drop?

You are talking about two different things. Voltage is measured at the source. Amperage is measured between the source and the component.

Put a DMM on the battery to measure voltage drops.