wtk: Amp power @ 12v estimate?

[zorced]

oye 2nrs
is there a standard conversion rate or formula, or is it dependant on the amp?
i saw some amps with half the power of 14v @ 12v.

Powerbass 600.4 2x30A fuses
14.4v Ratings
100 wRms x 4 @ 4ohm
400 wRms x 2 @ 4 ohm bridged.


12v
???????????

[noyztoyz]

to get power at 12.5v you normally minus 20% from the power ratings,

so it will drop to

80x4 @ 4
320 x2 @ 4 bridged

but for that amp you talking there man,

if you can get

50 x 4 @ 4 @ 12v u lucky,

some brands tend to seriously over-rate

[- Rovin's car audio -]

to get power at 12.5v you normally minus 20% from the power ratings,

so it will drop to

75x4 @ 4
300 x2 @ 4 bridged

but for that amp you talking there man,

if you can get

50 x 4 @ 4 @ 12v u lucky,

some brands tend to seriously over-rate

u sure that is d right way to calculate it ...what about doing d math using fuse rating ...

[noyztoyz]

i made a change to my values up there just now lol

i did not apply fuse rating just now because he just asked how you would deduce 12v ratings given 14.4.

[3stagevtec]

some amps make very close to or even surpass their 14.4V ratings even at 12V.. it all depends on the build of the amp..

[zorced]

hm both good and bad feedback..

that rel sad tho :/

[t&t tech]

Using the fuses on the amp calculation will give you the correct current ratings of the amplifier in question, once of course you know how to do the math properly! Which is not the case in most instances! The base voltage is normally calculated at around 14.4 volts which stipulates an adequate chrging system!

[viking1705]

fuse rating x voltage x known efficiency i believe however you may not know the efficiency of all amps..each brand of amp has a different efficiency rate as well as your car may not always charge at 14.4 volts.if you know the efficiency of the amp then use this multiply by the fuse ratin and by your charge rate be it 12,13,14 volts whatever.

[noyztoyz]

a rockford with a 60a fuse was almost twice as loud as a cadence with a 60a fuse,

what does this mean?

fuse ratings cannot be used jess so to make power estimations these days

[kurpal_v2]

some amps make very close to or even surpass their 14.4V ratings even at 12V.. it all depends on the build of the amp..

[viking1705]

a rockford with a 60a fuse was almost twice as loud as a cadence with a 60a fuse,

what does this mean?

fuse ratings cannot be used jess so to make power estimations these days

maybe that rockford amps are more efficient a higher efficiency will produce a higher power rating..the cadence prolly rell inefficient compared to the rockford..rockford has been known to use high quality products in their amp builds so i agree with 3stage it depends on the build of the amp

[nervewrecker]

also depends on how the amp is rated, lower end amps are rated at 1khz so they produce less power @ lower frequencies.

[jeff]

oye 2nrs
is there a standard conversion rate or formula, or is it dependant on the amp?
i saw some amps with half the power of 14v @ 12v.

Powerbass 600.4
14.4v Ratings
100 wRms x 4 @ 4ohm
400 wRms x 2 @ 4 ohm bridged.


12v
???????????

to tell you the truth.....
you are not going to be able to tell the difference unless you listen to music with a clamp and a multimeter

this difference will only become apparent in extreme cases of spl
otherwise with the dynamic nature of music your amp will prob never even pull more than half its power for normal music purposes

[SR]

shhh



real educated responses going on


doesnt the amp have a regulated power supply???

how does that equate to 20% in power output

[rigman00]

finally some sense steps in

[t&t tech]

[quote="noyztoyz"]a rockford with a 60a fuse was almost twice as loud as a cadence with a 60a fuse,

what does this mean?

fuse ratings cannot be used jess so to make power estimations these days[/quote]

Wrong! A fuse can always be used to estimate the power capacity of an amplifier, after all, isn't the fuse the very component that will decide how much current flows in and out of the amplifier!
To mr viking, 14.4 is a reference voltage because as i stated before this voltage stipulates an ADEQUATE charging system!

[zorced]

oye 2nrs
is there a standard conversion rate or formula, or is it dependant on the amp?
i saw some amps with half the power of 14v @ 12v.

Powerbass 600.4
14.4v Ratings
100 wRms x 4 @ 4ohm
400 wRms x 2 @ 4 ohm bridged.


12v
???????????

to tell you the truth.....
you are not going to be able to tell the difference unless you listen to music with a clamp and a multimeter

this difference will only become apparent in extreme cases of spl
otherwise with the dynamic nature of music your amp will prob never even pull more than half its power for normal music purposes

wta..
so i shouldnt expect anything near 3/4 the rated power @ 14.4v using a 12.5v system?

[Brian Steele]

Using the fuse rating to estimate the output of an amplifier is a bit like using engine displacement to determine a car's top speeed....

[De Hero]

Is anyone (even the high end brands) still making regulated power supply amps like the old PPI's/Hi Fonics/Alpines nowadays ?

[SR]

yes
but good power supplies cost money so the amps arent cheap

[viking1705]

a rockford with a 60a fuse was almost twice as loud as a cadence with a 60a fuse,

what does this mean?

fuse ratings cannot be used jess so to make power estimations these days

Wrong! A fuse can always be used to estimate the power capacity of an amplifier, after all, isn't the fuse the very component that will decide how much current flows in and out of the amplifier!
To mr viking, 14.4 is a reference voltage because as i stated before this voltage stipulates an ADEQUATE charging system!

i understand wa you sayin my comment was directed to the original poster.if he has not done any big3 upgrade he might charge at a lower rate so i am tellin him to do the calculation usin his charge rate to get a more accurate reading of his amps power.

also agree with sr there them amps are very pricely..some of the brands i know off will be like zapco,jl and some of the directed electronics

[Brian Steele]

A fuse can always be used to estimate the power capacity of an amplifier, after all, isn't the fuse the very component that will decide how much current flows in and out of the amplifier!

Wrong. Wrong. Wrong. Wrong.

The rated current for a fuse is the maximum amount of current that the fuse can carry continuously. It can actually carry greater than that for brief periods, and how fast it blows depends on how much greater current it's carrying and how long it's carrying it.

However, the fuse says ABSOLUTELY NOTHING about the efficiency of the amplifier, which determines how much of that input power is turned into output power, and how much is turned into heat. It also says nothing about the power supply and output stages of the amp, which determine how much peak output it can provide.

A class A amp and a class D amp may have the same 30A inline fuse, but I'm going to bet that the class D amp would be capable of significantly greater output.

BTW - my MTX amp has two 25A fuses. You think if I swap those fuses for 40A fuses, that will make my MTX amp more powerful?

Chuts man...

[viking1705]

A fuse can always be used to estimate the power capacity of an amplifier, after all, isn't the fuse the very component that will decide how much current flows in and out of the amplifier!

Wrong. Wrong. Wrong. Wrong.

The rated current for a fuse is the maximum amount of current that the fuse can carry continuously. It can actually carry greater than that for brief periods, and how fast it blows depends on how much greater current it's carrying and how long it's carrying it.

However, the fuse says ABSOLUTELY NOTHING about the efficiency of the amplifier, which determines how much of that input power is turned into output power, and how much is turned into heat. It also says nothing about the power supply and output stages of the amp, which determine how much peak output it can provide.

A class A amp and a class D amp may have the same 30A inline fuse, but I'm going to bet that the class D amp would be capable of significantly greater output.

BTW - my MTX amp has two 25A fuses. You think if I swap those fuses for 40A fuses, that will make my MTX amp more powerful?

Chuts man...

[t&t tech]

No mr brian! I don't think if you replace the specified fuse with a larger one it makes the amplifier more powerful! I was talking about calculating using the specified fuse for the amplifier! I thought that fact was obvious! But i was wrong!

Re-read my post fellas before y'all decide to kill people! I said you can use it to ESTIMATE the capacity of the amp! This of course is providing you're calculating with the stock fuse size of the amplifier in question!

Never said anything bout any other factors!

[3stagevtec]

I've seen amps draw current well over their fuse ratings without ever blowing them!

e.g. The Sundown SAZ1500D has 160A of fusing on it, but several competitors have achieved up to 2500Wrms from each amp during competition use.. If you do the maths, that equates to a current draw well over 230A and yet i don't hear about them blowing fuses..

Remember fuses require a certain amount of current over a certain amount of time to blow..

[t&t tech]

Ok fellas! Allyuh win! I can't argue with allyuh cuz allyuh making allyuh points from all over the place! The point was to help the OP with estimating power, allyuh start with fuse sustaining current over the specified limit and amplifier efficeincy!
I mean be real fellas, i know allyuh like to argue, buh argue one point nah! I really cyah read minds, so i cyah argue all the different points all at once!

[noyztoyz]

a rockford with a 60a fuse was almost twice as loud as a cadence with a 60a fuse,

what does this mean?

fuse ratings cannot be used jess so to make power estimations these days

t&t tech
what is said in this post and what Mr. Steele is trying to say is that you cant just watch the fuse on an amp only and decide how much power it will give,

you have to watch the efficency as well, and more importantly these days the brand of the amp. Thats why i used the comparison between the rockford and the cadence.

And its ok to argue these things until you understand because remember only one person ever round here was born knowing everything. And hes not a teacher.

[viking1705]

we're arguing the different pionts because all these points will determine the output of an amplifier. they are the variables that hav to be considered..we dont really argue here we jus post what we know is no hard feelins or anythin.non of us might be 100% correct then again we all might be correct not just one person. who knows..but at the end a the day i sure all of us probably learn somtin new.probably hear somtin they forget to take account of.its how we learn t&t tech

[i am an idiot]

Hope you guys don't mind me hijacking the thread, just decided to drop in my 2cents!

If you want to try to determine the amplifier's power output, the efficiency of the amplifier class won't be a factor. Efficiency is a factor when you are trying to find out how much power is being pulled from the source.

Truth be told, you can't determine your amp's power output unless you put it through a controlled bench test. But if it's a respected brand you should use the manufacturer's published RMS output data. Specs should be reported at both 14.4 volts and at 12.6 volts from the source. But even if there is only one source voltage showing in the specs you can extrapolate the wattage to conform to your vehicle's actual battery voltage measurement under full load conditions (as when you are playing the system). If you take readings consistently at 13.1 volts at the battery under load conditions, find the value per volt and then you can conform the published data to fit your actual vehicle.

[southside connections]

i am an idiot,

this is your name? u serious homy?

dread dat kinda name made me not read your post