ohm and RMS?

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=70369
Printed Date: May 29, 2024 at 5:15 AM

Topic: ohm and RMS?

Posted By: dave mortis
Subject: ohm and RMS?
Date Posted: January 08, 2006 at 11:08 PM

Hi,

I have 2 Earthquake DBX SVC 400 WATT RMS @ 4 ohm subwoofers whitch i'd like to connect to a suitable class D mono amplifier.

Now here's my question (^_^)

How many WATTS RMS does the amplifier have to give @ 4 ohm, 400 Watt RMS? or 800 Watt RMS? or somewhere in between?

Or is it better to connect the subs into 2 ohm?

Help please i'm totally confused :oops: (^_^)

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It's a me Mario!

Replies:

Posted By: stevdart
Date Posted: January 08, 2006 at 11:17 PM

Look in the left column at "Woofer Wiring". Enter two subs, SVC 4 ohm. You'll see a diagram appear that shows a parallel-wired combined impedance of 2 ohms. That load is acceptable for a class D mono amp, and the amp will be rated at a 2 ohm load. Look for output from 500 watts to 800 watts into 2 ohms when choosing an amp, so that each of the two subs receive between 250 watts to 400 watts. Here is an example of a suitable amp. Notice the power rating: 750 W X 1 @ 2 ohms RMS.

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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.

Posted By: dave mortis
Date Posted: January 08, 2006 at 11:30 PM

Thank you very much for the reply!

Do i need to look for output from 500 watts to 800 watts into 2 ohms RMS or music power?

Greets from Belgium

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It's a me Mario!

Posted By: stevdart
Date Posted: January 08, 2006 at 11:35 PM

A good amplifier will rate at RMS. "Music power" is a non-standard term, as is "peak power" or "max power". And welcome to the forum.

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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.

Posted By: kirktcashalini
Date Posted: January 09, 2006 at 7:29 PM

you can either wire the two subs at 8 ohms, or 2 ohms. A Class D amp will be better if you ran the 2 at 2ohms. which means connect both the positives, and both the negatives, then hook them into the amp. most amps will rate for example 1000watts@1ohm, 500@2ohm, 250@4ohms. In this situation, all that is important to you is that number of RMS power given at 2 ohms. look for what suits you, if you are safe run 600 or less, if you dont care about possibly blowing subs, go as high as you want and just watch for clipping posted_image

good luck and have fun with it all.

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99 Blazer LT. Yellow Top. Big 3. Infinity Kappa Speakers All Around. Jensen CD/DVD flip out. 2 Infinity Kappa Perfect 12DVQs powered by a Alpine PDX600.1 (in one custom box, building a FG box)