what happens in 1ohm VS. 4ohm?

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=63557
Printed Date: May 23, 2024 at 3:55 PM

Topic: what happens in 1ohm VS. 4ohm?

Posted By: spitfireguy1185
Subject: what happens in 1ohm VS. 4ohm?
Date Posted: September 30, 2005 at 4:30 PM

I know that in 1ohm there is less resistance in a woofer and the amp heats up a little quicker and i can get a little more SPL but i notice the battery gauge dips a little more in 1ohm than 4ohms...but why?

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Bass-oholik

Replies:

Posted By: Satkunas
Date Posted: September 30, 2005 at 5:01 PM

Your right on track. Because the amps load is lower, it requires more current from your electrical system.

Using Ohm's law (V=IR) I=V/R. If you 1/4 the resistance (4 ohm to 1 ohm) the amp needs 4x the current to maintain the same voltage. But since no amp is 100% efficient, and depending on the amplifiers voltage regualtion it's internal power supply will run out of juice alot faster, thus putting more strain on your car's electrical system at peak output. Adding a second battery or stiffening capacitor to the electrical system will help support the amplifiers demands during these transients.

Posted By: audiocableguy
Date Posted: September 30, 2005 at 5:20 PM

Voltage up, Amperage down.
Amperage up, Voltage down.
This is very simplified and I'm sure someone here can give you the math. When your electrical system is under load your voltage will drop So the alternator and battery must supply more current to supply the load.

Running an amp at 1 ohm either bridged or stereo has many disadvantages. The amp is going to run very hot, the amp will be drawing maximum current, and dampening will suffer (amp's ability to control cone motion). Another side effect is the loss of headroom. (amps reserve power storage). At this point clipping becomes a big concern. Clipped power blows speakers. You are forcing the amp to give all it's got and when it has no more to give, somethings going to break. . .