I was talking to a guy yesterday that majored in audio and electronic engineering and he told me that ohms are a common misconception. He said that it was possible to run subs with a no ohm load and virtually no power. He had to no name subs and a ****ty 50X2 at 4 ohms amp, but they could hit as hard as hell!!! They were loud enough that you couldn't turn them up all the way. Can you explain this to me? Is it true. If so I could make my 2 JL 15W1's bump louder than imaginable.

 

An amp will deliver voltage to a sub. The lower the resistance (ohms) of the sub, the more current it will pull. Power (watts) is equal to voltage times current. This is why the power increases as the amp delivers more current to the lower load.

Im not an engineer, just high school level physics here. But it is impossible to present a 0 ohm load to the amp. Even wire with no sub has resistance. But for arguments sake, if we presented a near 0 ohm load (say , .001 ohms), the amp will short out, becuase the very low ohm load will draw and extremely large amount of current, and the amp will either go into protection mode, or bite the big one.

If an amp is rated to only handle a 4ohm sub, then presenting it with an even lower value will exceed the specs of the amp, and it will shut down.

I'm interested in your friends theory on this.

BTW, it is possible to make your JL's louder. Build a big ported box tuned to 45hz. May not be the best for SQ, but it will be loud.

mike

------------------
custom 3rd gen kickpanels at http://www.lachernet.com/kickpanels

 

thanks for the input. I agree with you and will try to get more information from him and try to learn about his theory.

 

DJ about covered it. For arguments sake lets say that you had magic piece of wire that had 0 resistance and you bridged it between the output terminals, as he said the amp would pretty much self destruct, or at least go into protection and blow a few fuses.

As far as the "not being able to turn it all the way up" that is not necessarily the sign of a good setup, that just means that you are overdriving the speakers or amp and should back the gains down. A good system should be able to reproduce clean sound through low, mid and high volume without distorting, bottoming out speakers, clipping, etc...

Just something for you to chew on.

------------------
Carl
CarAudio Resources

 

Idiots like him are what give so many of us a bad reputation.

It was already explained well by a couple guys, so I'm not going to repeat that, but I will offer this:

Speakers are not truely a resistive device. Speakers are reactive. The difference is that a reactive load is basically a resistance that changes with frequency. Capacitors and inductors are purely reactive, while a resistor is purely resistive. A speaker has a resistive and a reactive element. A 4 ohm speaker has a resistance of 4 ohms, but the amplifier will see a much more complex load than that because of the reactive component.

But, anybody that says that an amp can drive a zero ohm impedance is an idiot.

------------------
The IROC Homepage
<A HREF="http://www.rit.edu/~jli4307/camaro" TARGET=_blank>
View the restoration of an 85 IROC</A>
"I didn't know a bored out Ford could go so slow" -Shenandoah

 

there is no 0 ohm anything.. speaker, wire, .. out best conductors are not 0 ohm. getting close.. but we'll never get there.. that's the electronic equivalent of eliminating friction.. try as we may.. it's always gonna be there.

Anthony

 

even if 0ohm did exist, it would just be stupid, you'd need a portable fridge to keep your amps in. a buddy of mine as two kicker xs100's and their rated at 50/2 @ 4ohms but they pump out 1200 watts mono. he wired all his ish up so that he was running at 1/2 ohm resistance through everything and his amps were too hot to touch after one song played. and no matter what the amps rated at, it can still make any subs thump