voltage output of my car

[Jakeeck 10+ year member]

i just read a thread where a guy emailed hifonics asking if the brutus series amps were rated accurately.. he says the rms is rated at 14v.. and for every volt lower... the amp loses 20% of its power..

so if the amp was rated at 1200 rms.. and u had a 13v output.. it would be only 960 rms at one ohm...

i just want to know how much voltage my car is putting out because i already have a hifonics 1200w rms brutus and im gonna be pissed if theres a huge difference in power.. im gonna be running my sub like this.. 4 ohm dvc at 2ohms.. so at rated it should do 900 rms.. but thats at 14v.. how much voltage would a 99 pontiac grand prix gtp put out with stock electrical?

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[skmfkr 5,000+ posts]

alt should put out 14v+, but with the amp pulling current it might drop. you need to get a digital multimeter to test it

 

[Jakeeck 10+ year member]

alt should put out 14v+, but with the amp pulling current it might drop. you need to get a digital multimeter to test it

ok so at my 2 ohm setup i should be atleast getting close to the 900w?

 

[skmfkr 5,000+ posts]

well i dont know what the amps rated output at 2ohms is and i dont know if your staying at 14v+ with the amp pulling current

 

[shaneb 10+ year member]

heres the deal.

1st. You will almost never see the full potential of the amp listening to music. Never.

2nd. Get a DMM and test your voltage at the battery while idling.

3rd. Test it with the amp playing at what you think will be "full power."

4th. Amps aren't rated listening to music.

All my amps are rated for more power than the speakers claimed "rated power."

We like to call it, Head Room.

 

[Jakeeck 10+ year member]

heres the deal.1st. You will almost never see the full potential of the amp listening to music. Never.

2nd. Get a DMM and test your voltage at the battery while idling.

3rd. Test it with the amp playing at what you think will be "full power."

4th. Amps aren't rated listening to music.

All my amps are rated for more power than the speakers claimed "rated power."

We like to call it, Head Room.

ya well my amp is rated 900 rms at 2 ohms.. which is what ill be setup with.. and my sub is rated at 600 rms. IA LI 15"

 

[shaneb 10+ year member]

then you shouldn't worry. cause you won't likely ever send 900 to a sub.

 

[n2audio 5,000+ posts]

heres the deal.1st. You will almost never see the full potential of the amp listening to music. Never.

2nd. Get a DMM and test your voltage at the battery while idling.

3rd. Test it with the amp playing at what you think will be "full power."

4th. Amps aren't rated listening to music.

All my amps are rated for more power than the speakers claimed "rated power."

We like to call it, Head Room.

Shane, I think the question is at two ohms on a standard electrical system will the amp perform like a 900w rms amp (whether it's actually producing that amount of power or not) or will it be something substantially less.

Jake, I think the idea of dropping 20% every volt has some merit, because any amp that isn't stiffly regulated will produce quite a bit less power at 12 or 13v than it will at 14, but with the HF I don't think it's that drastic.

At 2 ohms on a standard healty electrical system I think you should get 800w or so (I know shane).

And FWIW - it would be close to impossible to hear a difference between 800w and 900w.

I'd set the gain at 700w or so, that way you know the amp won't clip and the sub should get more than enough power to perform optimally.

 

[Jakeeck 10+ year member]

Shane, I think the question is at two ohms on a standard electrical system will the amp perform like a 900w rms amp (whether it's actually producing that amount of power or not) or will it be something substantially less.
Jake, I think the idea of dropping 20% every volt has some merit, because any amp that isn't stiffly regulated will produce quite a bit less power at 12 or 13v than it will at 14, but with the HF I don't think it's that drastic.

At 2 ohms on a standard healty electrical system I think you should get 800w or so (I know shane).

And FWIW - it would be close to impossible to hear a difference between 800w and 900w.

I'd set the gain at 700w or so, that way you know the amp won't clip and the sub should get more than enough power to perform optimally.

idk because the producer of the hifonics amps is the one who said that in an email.. and im new to this stuff so when i set the gains on my amp.. is there going to be one for wattage that just has little tickmarks going along it and then i have to measure how much is actually coming out with a meter.. or will it have a number on the gain?

 

[n2audio 5,000+ posts]

idk because the producer of the hifonics amps is the one who said that in an email.. and im new to this stuff so when i set the gains on my amp.. is there going to be one for wattage that just has little tickmarks going along it and then i have to measure how much is actually coming out with a meter.. or will it have a number on the gain?

measure the output voltage of the amp with a DMM, no load, while playing a 50hz 0db test tone at 80-90% HU volume. Sqt(700x2)=v is your target voltage for 700w, or about 37.5v.

Look at the gain setting tutorial in the stickies.