Power drop problems (HELP)

[twalker182]

That amp is rated 2k MAX.....not RMS.

I think only the Elite series do they rate at RMS.

[Krisztián Arnold]

42 minutes ago, mathewyocham said:

Wat is the batteries voltage fully charged at rest and during testing? Also do you have anything to measure your ohm load? Dmm?

The batteries fully charged are 12.9 volts, and at rest it is around 12.78.

During testing I do not really know to be honest, becaouse I either measure the amps AC voltage or the batteries DC, since I do not own 2DMMs. 

And that answers your last question. Also it is a true RMS DMM, so I think it is to be trusted.

[Krisztián Arnold]

36 minutes ago, twalker182 said:

That amp is rated 2k MAX.....not RMS.

I think only the Elite series do they rate at RMS.

The guy who sold it to me claimed it to be 2kW RMS... I guess he lied to me.

But BigDWiz did a dyno on the 3kW Brutus, and it did fine on dynamic power, so this gives me a flicker of hope.

[Kyblack76]

38 minutes ago, Krisztián Arnold said:

The guy who sold it to me claimed it to be 2kW RMS... I guess he lied to me.

But BigDWiz did a dyno on the 3kW Brutus, and it did fine on dynamic power, so this gives me a flicker of hope.

Dynamic power on the dyno, is a joke. Imho ..... Wish Derreck didnt even do that myself. But, whatevs.... 

On your "clamp test", where did you start, load wise (nominal), and end (reactive) ??? Did you see a 2.3ohm (just throwing that out there, but, i bet its close if your wired at 1ohm nominal)  reactive load?

Well, then, that board probably does around 1k or whatever at 2ohm. So, .... 800, with the for sure voltage drop you have, (starting at battery rest, your gonna end in the damn 11s id think full rip)  probably, is close to what your seeing.... Eh ??

  

[paidnfull]

2 hours ago, mathewyocham said:

Wat is the batteries voltage fully charged at rest and during testing? Also do you have anything to measure your ohm load? Dmm?

^^Here is where your answer lies.

 

Unless you're running a load resistor, your amp probably isn't seeing the 1 ohm load you think it is during testing.  Impedance is reactive/dynamic so the amp is seeing a load much different than you think it is.  The sub doesn't just sit at 1 ohm for the length of your test and is likely showing the amp something well over 2 ohms, which makes your 800 watts, or whatever, actually seem pretty good. 

That amp is probably in the 50% efficiency range, so figure it's drawing 150 amps or so to create 1000 watts. Two batteries probably aren't going to hold 12.6 very long with that kind of load on them without an alternator or power supply to keep them topped off.  I'd be surprised if they held above 11, thus further diminishing the power the amp is able to make. 

[paidnfull]

1 hour ago, Krisztián Arnold said:

The batteries fully charged are 12.9 volts, and at rest it is around 12.78.

During testing I do not really know to be honest, becaouse I either measure the amps AC voltage or the batteries DC, since I do not own 2DMMs. 

And that answers your last question. Also it is a true RMS DMM, so I think it is to be trusted.

You need three meters.  One to measure the ohm load, one to watch the dc voltage, and one to watch the ac amperage.

 

If all you are measuring is the ac voltage, you don't have even enough info to calculate watts.  The load needs to be resistive to use ohms law to calculate info in an ac circuit too, so if you're using a subwoofer (which is a reactive load), your results may not tell the whole story even if you have all the info you need (which you don't).

[Krisztián Arnold]

Thanks for your answers, and suggestions. But in the end it all levas me with a question an that is how come that there are many bassheads and car audio enthusiasts who measure their amps with the old "clamp test" way and still get their numbers? And also getting away with it using only one big ass AGM battery? 

[Krisztián Arnold]

28 minutes ago, paidnfull said:

You need three meters.  One to measure the ohm load, one to watch the dc voltage, and one to watch the ac voltage. 

 

If all you are measuring is the ac voltage, you don't have even enough info to calculate watts.  The load needs to be resistive to use ohms law to calculate info in an ac circuit too, so if you're using a subwoofer (which is a reactive load), your results may not tell the whole story even if you have all the info you need (which you don't).

So if I get a third meter, and read all three of the factors you mentioned, how do I measure the amperage? Because that is also needed inthe equasion. I do not want to be cantankerous or something, I only would like to learn.

[Krisztián Arnold]

50 minutes ago, Kyblack76 said:

Dynamic power on the dyno, is a joke. Imho ..... Wish Derreck didnt even do that myself. But, whatevs.... 

On your "clamp test", where did you start, load wise (nominal), and end (reactive) ??? Did you see a 2.3ohm (just throwing that out there, but, i bet its close if your wired at 1ohm nominal)  reactive load?

Well, then, that board probably does around 1k or whatever at 2ohm. So, .... 800, with the for sure voltage drop you have, (starting at battery rest, your gonna end in the damn 11s id think full rip)  probably, is close to what your seeing.... Eh ??

  

Why would dynoing an amp be a joke? Sure it is a condition, where everything is perfect, but it still gives you the idea of what you are dealing with, but it is only my two cents.

Also why should I see a 2.3 Ohm load?

[Joshdashef]

10 minutes ago, Krisztián Arnold said:

Why would dynoing an amp be a joke? Sure it is a condition, where everything is perfect, but it still gives you the idea of what you are dealing with, but it is only my two cents.

Also why should I see a 2.3 Ohm load?

He is referring to the dynamic power test that some people perform on the Dyno to be a joke. Not dyno-ing an amp itself.