How accurate is this chart

[mightycrappy 10+ year member]

http://www.caraudio.com/forum/showpost.php?p=1911183&postcount=10

I mean I'm sure it's pretty accurate, but just wasn't sure to what degree.

Cause apparently my buddy had his gains up half way and was pushing 1200W @ 4ohms on an amp only supposed to do 900W. But honestly I don't know how this works. He has some Lanzar 4000 something or another. Also he was pushing it on a TC-1000, which are only rated at 400W RMS.

I gave him a 50Hz -6db sound file to use to check amp outputs with DMM.

He only ran it for about a day. He didn't have any sound file to test. So he said he just turned up gain (while listening to music) until it started distorting and then backed off alittle. So I told him he should really test the outputs and emailed him the sound file. So, when he tested it with that file he said he was running at 70V.

So did he get lucky he didn't fry that amp or that sub?

Thank for anyone that cares to answer. If you don't that's cool too. //content.invisioncic.com/y282845/emoticons/fro.gif.c695f1f814b01c4ad99fe7f8cccadd29.gif

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[thch 10+ year member]

that came from the output of a python script i wrote up. my guess would be "better than 0.04% accuracy" as the least accurate measurement should be the 7.07V @ 1ohm ~= 50W. it is 0.0151W off.

 

[mightycrappy 10+ year member]

Cool thanks.

I figured it was, but just was wondering why his TC-1000 didn't blow or his Amp didn't die out running at 1200W. His amp is suppose to be only rated at 900W RMS @ 4 ohms.

Thanks again

 

[thch 10+ year member]

that is with a sine wave. an amp, when overdriven, can output more power than normal. up to 2x power (+3dB), of which +2dB occurs at the fundamental, and another +1dB is spread out as distortion.

 

[hoxie08 5,000+ posts]

that came from the output of a python script i wrote up. my guess would be "better than 0.04% accuracy" as the least accurate measurement should be the 7.07V @ 1ohm ~= 50W. it is 0.0151W off.

You are smart //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Grmanalishi 10+ year member]

Can you explain what the table is? Is the power the total power of the amp or the RMS? If I have an amp that's 110W RMSx2 @ 4 Ohms should I interpolate and find 220W? The voltage is the V required by the amp or the output V? Thx.

 

[helotaxi 5,000+ posts]

The table gives you the RMS voltage for a given power and impedance. If you need something for a different power than what is on the chart, multiply the power by the impedance and take the square root of the result.