Underrated, overrated... How do you know?

[anders213 10+ year member]

Just wondering how do you measure the true RMS of an amp yourself.

Cheers

Anders

Click to read more...

 

[squeak9798 5,000+ posts]

You don't, without a lot of expensive test equipment that most people don't have access to.

If you really want to know, pay a competent shop to bench test it for you.

 

[audiolife 5,000+ posts]

You don't, without a lot of expensive test equipment that most people don't have access to.
If you really want to know, pay a competent shop to bench test it for you.

it beats guessing

 

[cappy72 10+ year member]

I normally guess,,, any thing from walmart is definatly UNder rated I would give any walmart brand +300 watts rms

 

[Polecat 5,000+ posts]

Most reputable car audio manufactures are underrated, most lesser known brands are overrated...so if you see an 2000 watt amp for $149, you can almost guess. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Nukedsodapop 5,000+ posts]

Kickers WAYYYY overrated, just put it that way....

Lol j/p from what I hear and have seen Kickers underrated

//content.invisioncic.com/y282845/emoticons/veryhappy.gif.fec4fed33b4a1279cf10bdd45a039dae.gif

 

[InhumanAcura 5,000+ posts]

*TRUE RMS* clamp meter

DMM

Load (speaker/resistor)

Amplifier

Power Supply

teh mathematics

 

[the_noob 10+ year member]

So I can see why companies would overrate a product, but why under rate //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

Is it because of inadequate testing equipment or is there some other explanation that actually makes sense?

 

[supa_c 5,000+ posts]

Well...

If they underrate then they have a bottom RMS that the amps can be

So if its 1300W instead of 1200 then they have lee way.

I dunno..im wee turded

 

[Polecat 5,000+ posts]

it's always best to be underrated, if you say amp can do XXXX power into X ohm load at XX.X volts, it better do that, and more for the consumer...or, it should. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[the_noob 10+ year member]

it's always best to be underrated, if you say amp can do XXXX power into X ohm load at XX.X volts, it better do that, and more for the consumer...or, it should. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

ah, ok. That makes sense now //content.invisioncic.com/y282845/emoticons/thumbsup.gif.3287b36ca96645a13a43aff531f37f02.gif

 

[squeak9798 5,000+ posts]

Some of it is marketing. Like those older Pioneer PRS amps; IMHO those were underrated by so much on purpose simply so people would drool over them when they looked at the birthsheet compared to the "rated" power. I'm sorry, but you can't "over-engineer" something on accident by so much that every model makes more than double it's "rated" power. They knew going into it that the rated power was severely under what the amps were capable of. And look at what happened, everybody is always like "Man, those amps are awesome because they are soooo underrated!!"

 

[jsloan10 10+ year member]

Take a DMM (digital multimeter)

set it to AC voltage, with the appropriate sensitivity

hold test leads to the +, - of the channel being tested

blast tone or music at maximum unclipped level

record highest voltage displayed

multiply voltage by itself then divide by resistance of speaker connected to channel.

for example-

34 volts peak is recorded, channel is connected to a 2 ohm speaker/load

peak volts squared

34X34=1156

divided by resistance

1156 / 2= 578 watts

Peak output recorded as 578 watts, to obtain RMS voltage multiply by .727

578x.727= 420 watts rms

This is NOT the most accurate way to find the true RMS rating of your amplifier, there are a lot variables that are not accounted for when you test like this, therefore this test is only to be used to give a better understanding of what your amplifier is capable of doing.

 

[psych0ticnemes1 5,000+ posts]

Take a DMM (digital multimeter)set it to AC voltage, with the appropriate sensitivity

hold test leads to the +, - of the channel being tested

blast tone or music at maximum unclipped level

record highest voltage displayed

multiply voltage by itself then divide by resistance of speaker connected to channel.

for example-

34 volts peak is recorded, channel is connected to a 2 ohm speaker/load

peak volts squared

34X34=1156

divided by resistance

1156 / 2= 578 watts

Peak output recorded as 578 watts, to obtain RMS voltage multiply by .727

578x.727= 420 watts rms

This is NOT the most accurate way to find the true RMS rating of your amplifier, there are a lot variables that are not accounted for when you test like this, therefore this test is only to be used to give a better understanding of what your amplifier is capable of doing.

interesting //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif hope it works that way

 

[Raven 10+ year member]

That would probably work running a 60hz sine wave.