using DMM clarification on gain

[337ram 10+ year member]

Ok I have used the dmm to set gains before but I have a issue needing a answer, ok I always did the math, match my amp to my head units pre volt output, 4v, and I can get no wheres near my math setting of 69.??, now if I switch on the amp to less than 1v I can get he 69.?? Is this due to my stock electrical not being up to par, is ther harm is I leave it on the 1v and less setting on my amp? Also its a alpine pdx12 amp, running 4g power and ground wire.

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[Gregulate 10+ year member]

Go here, Wattage

it does the math for you.

 

[ahole-ic]

Go here, Wattage
it does the math for you.

That was not his question brah.

The answer to the question is that it's not that simple. You're assuming your head unit is putting out exactly 4v. It probably isn't. You're assuming that none of your crossovers have filtered the frequency you're using in any way. Maybe they have. Finally, you're assuming that your amp is calibrated perfectly for the gain adjustment. It probably isn't.

 

[Gregulate 10+ year member]

That was not his question brah. The answer to the question is that it's not that simple. You're assuming your head unit is putting out exactly 4v. It probably isn't. You're assuming that none of your crossovers have filtered the frequency you're using in any way. Maybe they have. Finally, you're assuming that your amp is calibrated perfectly for the gain adjustment. It probably isn't.

Good call. I need to read a few times before I respond.

 

[ahole-ic]

Good call. I need to read a few times before I respond.

No biggie. We all do it. You were just trying to help.

 

[EpicMango 10+ year member]

Go here, Wattage
it does the math for you.

Whoaaa. Does that tell me a rough estimate of the load thats going to be loaded from the alt?

Seems kinda low but I put

Amplifier Max. Watts: 600

# of Subs (Do not count VC's): 1

Voice Coils per Sub: 2

Resistance of each voice coil in ohms (Ω): 4

Wiring: Parallel

Load on amp: 2 ohms (exactly what I want)

Current: 17.32 amps

The current is where I went o.0

600 watts RMS will only pull 17.32 amps from my alt? That can't be right....is the calculator asuming that Max watts is doulble the RMS rating of the amp?

At 14.4v that number seems to be exactly half of what my calculations landed at. I have a 12v amp. THAT CALCULATOR IS NUMERIST!!!

Wuutt geeves?

 

[337ram 10+ year member]

That was not his question brah. The answer to the question is that it's not that simple. You're assuming your head unit is putting out exactly 4v. It probably isn't. You're assuming that none of your crossovers have filtered the frequency you're using in any way. Maybe they have. Finally, you're assuming that your amp is calibrated perfectly for the gain adjustment. It probably isn't.

Ok I know it's not dead on 4v there's to many known and unknown issues to drop it, but even in the plus 1 to 8 I should be able to get near my # correct? I can't get no where's near it

 

[ahole-ic]

Whoaaa. Does that tell me a rough estimate of the load thats going to be loaded from the alt?
Seems kinda low but I put

Amplifier Max. Watts: 600

# of Subs (Do not count VC's): 1

Voice Coils per Sub: 2

Resistance of each voice coil in ohms (Ω): 4

Wiring: Parallel

Load on amp: 2 ohms (exactly what I want)

Current: 17.32 amps

The current is where I went o.0

600 watts RMS will only pull 17.32 amps from my alt? That can't be right....is the calculator asuming that Max watts is doulble the RMS rating of the amp?

At 14.4v that number seems to be exactly half of what my calculations landed at. I have a 12v amp. THAT CALCULATOR IS NUMERIST!!!

Wuutt geeves?

No! That current is what your amp puts out to your subs. Not what it is drawing from your alternator.

 

[337ram 10+ year member]

I was reading somewheres when I order my alping pdx12 amp that others were having same issue and had to switch to the lowest setting, maybe its just the way it is?