Quick question on electrical

[nateberrier 10+ year member]

Sounds like you have a poor link somewhere. Maybe a have your batteries tested at autozone. Or the amp is super inefficient. I know that most pioneer amps and some of the hifonics used to dim my lights where as my crunch and kicker amps did not. It is a prototype after all.

 

[Bobby322 10+ year member]

Sounds like you have a poor link somewhere. Maybe a have your batteries tested at autozone. Or the amp is super inefficient. I know that most pioneer amps and some of the hifonics used to dim my lights where as my crunch and kicker amps did not. It is a prototype after all.

Batteries rest no lower than 12.6. Its def. not the amp

 

[hatedonmostly 5,000+ posts]

Batteries rest no lower than 12.6. Its def. not the amp

Measure voltage at the amp and batteries when at full tilt, then get back to us.

Resting voltage means nothing.

 

[Bobby322 10+ year member]

that's not how it works. How much current your amp sucks has nothing to do with what voltage your rcas are. The only relevant thing is how much power the amplifier is taking in order to generate the final output.
let me edit to explain this -

say you have an amplifier that is putting out an honest-to-God 2,000 watts (clamped). The formula we'll use is amps times volts = watts. If the amplifier is 100% efficient, it will take 166.66 amps of current at 12 volts to produce 2,000 watts. Your amp will **** 166.66 amps at 100% efficiency.

Now, say you have a new amp, which is producing 2,500 watts (clamped) , but you have a voltage drop to 11 volts, and your efficiency is 90%....

2,500= (11 times Xamps) * 0.9 and you'll see that you're now drawing 252.52 amps of current!!!!

I see, and the lowest I go is in the low 12s. I mean that maybe the low preamps on the HU cause me to crank the gain up too high which makes it clip, which makes voltage drop

 

[Bobby322 10+ year member]

Full tilt as in gain 100%? Or just as it is (about 3/4)

 

[Bobby322 10+ year member]

Just played it at 3/4 gain and checked the voltage at the amp it it went down to the 11s!!! Made a video- uploading.

 

[Bobby322 10+ year member]

Just did the same test but measured voltage at the battery and it didn't dip down as low as at the amp. I then measured the length of the ground to the amp and its nearly 3ft.

http://www.youtube.com/watch?v=yao2jncuB08

 

[WheresTheButta 10+ year member]

I'm far from an expert, I just know enough to tell you that your problem is simple - you're drawing too much current. I have a feeling it's almost exactly the situation I laid out for you, where you have an amp that's putting out more power than you're used to, but with less efficiency.

BTW your gain isn't a volume knob... It's not like cranking it up is "full tilt" - full tilt is what we use to describe the loudest level we can *safely* achieve! The operative word is safely. Think of it like the redline on a car. The gain knob is used to match the amount of input to the amount of output. In other words, it's just a switch that changes how sensitive your amp is to the input you're giving it.

 

[Bobby322 10+ year member]

So 234ah of battery power, 4 runs of 0 gauge, and big 3 isnt enough to support say 2500w? I read the voltage of my alt at idle and it was about 13.8v.

 

[WheresTheButta 10+ year member]

So 234ah of battery power, 4 runs of 0 gauge, and big 3 isnt enough to support say 2500w? I read the voltage of my alt at idle and it was about 13.8v.

I really think it's a simple thing - even if you have TONS and TONS of battery power, you will deplete them if you don't have sufficient charging to back it up. Think of batteries like a bathtub full of water, and your charging system is the faucet that's filling the tub. As you turn up the volume, it's like opening the drain to let water out. If you are letting out more than you're putting in, eventually you will run dry - even if you have 1,000 batteries, you'll drain them eventually if you don't have enough charging capacity. If you are drawing 250A but you're only putting out 130A at your alt, that's a deficit of 120A - just think about that!!!

simply put - it seems like you've already explored all other options, and are left with a cold reality - it sounds like you need a bigger alternator