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Can someone explain ohm's to me?

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Old Jun 2, 2005 | 02:14 PM
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Default Can someone explain ohm's to me?

Ok, I'm looking to add more bass to my stereo but all this stuff about ohms is confusing the hell outta me. Like, an amp. is putting out twice as many watts at 2 ohms than it does at 4 ohms. How do I know if I'm running at 2 or 4 ohms?
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Old Jun 2, 2005 | 02:24 PM
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Check this out.

Ohm's Law & Car stereos
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Old Jun 2, 2005 | 02:28 PM
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If it's possible I think that site confused me more. LOL
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Old Jun 2, 2005 | 03:01 PM
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It's more complicated than this but this is the basic idea...

V = volts
P = power in watts
R = resistance in ohms

Cars only have a small amount of volts available, about 12v. This is why speakers intended for cars have very low ohms.

P = (V x V) / R

For a 8 ohm speaker:

(12 x 12) / 8 = 18 watts

4 ohm:

(12 x 12) / 4 = 36 watts
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Old Jun 2, 2005 | 06:04 PM
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An ohm is a measurement of resistance.

A watt is a measurement of power/work.

An ampure is a measurement of current flow.

A volt is a measurement of potential difference (pressure).

As was stated above the car's voltage is low so in order to get more work done current flow is increased. Put it another way using water - in order to fill a bucket with water you can use a high pressure hose (high voltage) and fill the bucket very quickly with very little flow (amps) OR you could use a very low pressure hose that was huge in diameter and fill it very quickly with lots of water flow (electrial current).
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Old Jun 3, 2005 | 05:15 AM
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Some more good reading: http://www.the12volt.com/ohm/ohmslaw.asp
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Old Jun 3, 2005 | 06:18 AM
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Wow...that's really...technical. My mind can't take that stuff during the summer. LOL

Can someone just tell me what I have to do to get 2 subs to run at 2 ohms? That's what I was trying to figure out.
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Old Jun 3, 2005 | 07:13 AM
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Either get 2 4 ohm Single Voice Coil subs (SVC) or get 2 2ohm Dual Voice Coil Subs (DVC). 2 4ohm DVC subs can not yeild 2 ohm amp loads..
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Old Jun 3, 2005 | 07:23 AM
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Ok cool. That helps a lot. Now I know what I need to look for.
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Old Jun 3, 2005 | 12:50 PM
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It's all pretty simple really. You see electronics work using smoke, if you let the smoke out they won't work.
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Old Jun 3, 2005 | 01:19 PM
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Originally Posted by Santacruzslick
Can someone just tell me what I have to do to get 2 subs to run at 2 ohms? That's what I was trying to figure out.
Look at the instruction manual. If you go to JL's site, they'll tell you exactly how to wire their subs to get specific ohm figures.

Also, don't just go out and buy any sub. The sub must be designed to work at 2 ohms. i.e. you can't turn a 4 ohm sub into a 2ohm sub.
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Old Jun 3, 2005 | 01:21 PM
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this helps with wiring. http://www.edesignaudio.com/wiring.php
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Old Jun 3, 2005 | 02:27 PM
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My current sub is wired with positives going to positives and negatives to negatives. The second diagram shows it wired the way you would wire batteries together. The + of one side to the - of the other side then connecting the remaining ports to the amp. Is that better than splitting the + and - wires and running only + to + and - to -.

Basically what I'm asking is...from the top 2 diagrams on badfish25's post, which is better for hooking up one sub?
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