how hard does the amp work?

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=108126
Printed Date: May 16, 2024 at 5:02 AM

Topic: how hard does the amp work?

Posted By: rfhvhtoo
Subject: how hard does the amp work?
Date Posted: October 13, 2008 at 10:47 AM

If a amp is say 400x4 @4ohms and 800x4 @2ohms and you have 4 subwoofers that are 100 watts rms. Would the amp work as hard if you had the subwoofer hooked up at 4 ohm each to get out 100 watts. or to connect 4 2ohm subwoofers so the gain would only have to go half as far?

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Replies:

Posted By: DYohn
Date Posted: October 13, 2008 at 11:04 AM

The power rating on a speaker means nothing in terms of the load it will place on an amp. The speaker's impedance is what determines how much current it will draw. A 2-ohm load will draw approximately twice the current of a 4-ohm load at the same voltage level (Ohms' Lam.)

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Posted By: KPierson
Date Posted: October 13, 2008 at 12:33 PM

You shouldn't adjust the gain if you change the ohm level (or the output of the amp) as the gain is NOT a "volume" control - it IS a compenstation adjustment for the input of the amp to match the output of the head unit you are using. Once the gain is set you shouldn't ever have to adjust it, no matter what sub combination you throw at the amp.

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Kevin Pierson

Posted By: rfhvhtoo
Date Posted: October 13, 2008 at 4:45 PM

So if I have the amplifier adjusted to exactly to 100watts for a 4 ohm subwoofer (measured on meter and all). and I put a 2 ohm subwoofer on it. it would automatically get 200 watts rms? and if so is the amplifier working any harder or is it working less. or the same?

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Posted By: DYohn
Date Posted: October 13, 2008 at 5:30 PM

Yes, if an amplifier produces 100 watts into 4-ohms and you connect 2-ohms to it (assuming it can handle the 2-ohm load) it will produce 200 watts with the exact same settings and input level. Producing more power of course requires more "work," so to speak, as well as more power supplied to the amplifier from the electrical system. Nothing is free.

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Posted By: rfhvhtoo
Date Posted: October 14, 2008 at 4:16 PM

Thats what I was lookin for Thanks alot for the help guys.

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