using a dmm under 4 ohm load my amp does 45 volts a/c.

[DidUHearThat? 10+ year member]

/facepalm...

 

[05fronty 5,000+ posts]

i used to have a 1502 and a 3002. i doubt those you have do that much power. they are underrated yes but not that much.

 

[stanky1219]

i didnt think so. but they definetly do more than 150. lol. i can move a lot of air for 1 15 on only an alleged 300 watts total.

 

[smgreen20 10+ year member]

Well, I'm out. I've doing car audio for over 17 years and it's the last 10 that I've really gotten into the depths of it. I have more real world knowledge on how to do all most anything one needs to do/know in the car audio industry. Yea, I don't know it all and I'm willing and ready to learn more. I originally stated that to do it right you'd need an O-scope and a true rms DMM.

Like I also stated, I have a hard time putting into words that make sense what to do or what I mean. So to keep from entering into what could turn into a pi$$ing match, I'm out. I will continue to follow this thread though.

 

[stanky1219]

i started it and i'm out too. i said to hell with benching them. with 41vac out of each amp on a 50hz tone it seems that i got my gains perfect. sounds great and my sub doesnt heat up anymore. the amps still run hot as **** but they always have since they were new 13 years ago.

 

[Haunz 10+ year member]

Same as as said before. There is only one way to test an amplifier in a car. This is what I call "real world power". Bench testing is all fine & dandy to see an amplifier's capability in perfect conditions but this isn't the way these amplifier's are used on a daily basis. We don't listen to dummy resistors. We listen to speakers/subwoofers (aka reactive loads) and different amplifier designs work completely different in these scenarios. That's something you won't see on a bench. My amplifiers don't play into a dummy load with a signal from a tone generator daily. They play music from my head unit into my subwoofers. I'd rather know what my amplifier can do sitting in my vehicle instead of sitting on a test bench.

You're confusing opinion with fact. The fact is in car testing is only meaningless in your opinion. In my opinion in-car results are all that matters. Bench ratings are only good for advertisement purposes. "Look at how much power this amplifier made on our test bench under perfect climate controlled circumstances with zero voltage drop from our power supply and zero impedance rise from our dummy load even though your vehicle will never replicate any of these circumstances and you'll never actually see this amount of power out of this amplifier in your setup "

Dude, DidUHearThat? is 100% right as far as I am concerned.. Testing the power output into a sub with a clamp and dmm will only give you the apparent power.. The real power could be anything, but rest assured it will be significantly less then what you are measuring... If you could account for inductance and capacitance of the sub, you could account for power factor and come up with some real numbers... the problem is even if you measure these parameters with an LCR meter, they actually change with the position of the cone and the mechanical load on the driver...

The only way to test the real output power of an amplifier is by using a non-inductive dummy load... this will present the worst case scenario for the amp (constant load, no impedance rise)... and it dosen't necessarily have to be done on a test bench either...

So many people test output into thier drivers which are an unknown reactive load and claim their amp makes XXXX amount of power; when they have really measured nothing but thier own ignorance (IMHO)... further, they measure the current pulled by the amp which is accurate and now believe thier amp is more efficient then it really is as well...