how to figure the amps efficiency?

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=83936
Printed Date: May 21, 2024 at 8:47 AM

Topic: how to figure the amps efficiency?

Posted By: stang351w
Subject: how to figure the amps efficiency?
Date Posted: October 09, 2006 at 9:12 PM

i've been doing some research trying to figure out how to find out the actual output of an amp. and i'm getting a little confused.

test amp, kenwood kac-811D mono sub amp

it's rating is 533W @ 4 ohms mono

919W @ 2ohm mono

and 1016W @ 1 ohm mono

with a poor s/r ratio of 74dba

those are all measured at 14.4 volts. and it has 3 x 25A fuse's

i'm mainly trying to find out if this amp will run 1000 rms befor it blows up or shuts down. i've got a customer that bought a DD 3512 and he's bent on keeping this amp so i'm just wondering how efficent this thing is and weither or not it's getting close to 1000 rms or if the peaks 1000 rather then 1600.

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Tri County KustomZ
certified installer

Replies:

Posted By: haemphyst
Date Posted: October 09, 2006 at 9:48 PM

25X3=75A in, peak
75AX14.4v=1080W in, peak

By my calculations, NO, it won't run 1000w. That would be a PEAK value. Continuous power would likely be around 600 to 650 watts, on a good day. Typical Kenwood... not exactly a fan.

Impedance means nothing... read here... It explains MUCH more, and I don't want to type it all again.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Posted By: stang351w
Date Posted: October 10, 2006 at 9:22 PM

thanks for the reply, those are close to the numbers i was getting, just was double guessing myself. but just one last question, if it has a peak in of 1080 watts with 75A of fuseing, then how could they possibly say that it would run 1600 peak? or even come close to that number.. or is that with 16volts, everything wide open and peak amprage being pumped into it?

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Tri County KustomZ
certified installer

Posted By: haemphyst
Date Posted: October 10, 2006 at 10:33 PM

100ms, 1K burst, probably.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Posted By: stevdart
Date Posted: October 10, 2006 at 10:50 PM

I believe a lot of the ratings, especially peak numbers, are mathmatically obtained..........

.......using Chinese arithmatic.

posted_image

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.