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I math & ohms.

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=139262
Printed Date: May 06, 2024 at 12:33 AM


Topic: I math & ohms.

Posted By: speakeasypete
Subject: I math & ohms.
Date Posted: August 01, 2015 at 2:49 PM

I visited the ohms calculator and still can't figure out how they came up with the sum.I was thinking of connecting three 4 ohm speakers in parallel.My math shows 5.3, calculator shows 1.3.Can some body explain?

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Replies:

Posted By: i am an idiot
Date Posted: August 01, 2015 at 8:57 PM
Anytime you parallel 2 resistors or voice coils, the outcome is always lower than the lowest value resistor in the equation. The correct answer it 1.3333

Anytime you parallel 2 like value resistors it simply cuts that value in half. 4 plus 4 = 2   When you parallel the now 2 ohm load with the 3rd 4 ohm driver the math is 4+2=6   4x2=8 8/6=1.333333 There is more to the equation but this is how Ohms law comes up with the answer.




Posted By: i am an idiot
Date Posted: August 01, 2015 at 9:01 PM




Posted By: knudsen
Date Posted: August 05, 2015 at 6:30 AM
When all the resistor (or VC) values are the same, there is a shortcut. Just divide the value in ohms by the number of resisters or VCs in parallel.

4ohm/3 = what i am said

Keeping in mind that VCs are seen by AC or an audio signal as impedance, or in practice an LRC circuit, and impedance varies with frequency, IMHO it would not be best practice to parallel VC's to a value that is very close to the minimum rating of the amp. That's why the VC's impedance is "nominal." At lower frequencies, less impedance is seen by the amp. With variations between speakers, and other factors that create an unknown and unwanted LRC circuit, when you parallel, the impedance becomes "nominal and approximate." Not saying parallel is bad, just saying cover you assmp. 1.33 ohms is too close for me, but YMMV, and the pro's here have 1000 X the practical experience that I do.

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Build a man a fire, he keeps warm for a day. Set a man on fire he stays warm for life!





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