8 ohms=180 watts. 16 ohms=????????

[kenratboy]

I just got a plate-subwoofer amp from partsexpress.com and I have a question about it. If you have seen some of my other posts, I got a JBL Professional 4648A-8 subwoofer and one of the 15 woofers is broken, and going back to the factory for repair, anyway, each woofer is 16 Ohms, and as I only have one, my sub is currently presenting a 16 ohm load. The subwoofer amp I got puts out 250 watts at 4 ohms, 180 watts at 8 ohms, but what should it put out at 16 ohms? Would it be about the same as the 8-ohm power load, or about 100 watts? It is not rated for 16 ohms because there are not very many 16 ohm speakers, and, the amp will probably never have it this easy again!

Thanks for the help!

[tgourlie]

probably around 100, And I believe it will be pushing less amps. Not sure about that though, I'm still trying to capture that idea after a H/K rep got me all confused. oh well. But yeah if that amp thing is right then you would be getting about the same watts to your one sub but less amps. Cause the wattage would be split between the two paralleled subs. 180/2=90watts. Hope that helps, and is right. If that amp thing is wrong somebody please straighten me out cause that guy from h/k was saying some stuff that really got me confused.

[JohnA]

P=IxV and V=IxR Where P= power, I=current, R=resistance and V=voltage.

Rearranging the above, P=V**2/R (V squared). Power amplifiers are essentially voltage sources, meaning their output voltage is pretty much the same no matter what the load is. If V is held constant and R is changed power is changed. If the resistance is doubled, the power is cut in half. If the resistance is cut in half the power doubles.

Since we don't live in a theoretical world, there are limits, particularly in the power supplies of amplifiers. As the resistance falls, the power supply is called on to put out greater amounts of current until it just can't anymore. Below that point, the power doesn't increase linearly and the amp's output voltage actually falls further limiting power.

It appears your amp is current limited just above 4 ohms (it can't double its power from 8 to 4 ohms). Going the other way from 8 to 16 ohms, it won't be limited and the power will halve, i.e. 90 watts.

If your amp is underrated and can actually put out more than 180 watts at 8 ohms, it will put out more than 90 watts at 16 ohms.

John

[APPLEBITE]

whoa, there's some technical bable for ya. I might get that if I read it a few times

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JVC 36" tv

Technics DA-10 Reciever

Klipsch KSW-10 sub

Klipsch RC-3 II Center

Klipsch RB-3 Surounds

Nuance Fronts

Hitachi DV-P415U dvd player

[WMcD]

I'm in agreement with John.

This issue going down to 4 ohms is that the power supplies can't supply the current. Then the voltage sags.

However, the 16 ohms is drawing current probably without a sag.

Gil

[Hiamperage]

Uh, i was just gonna say 90 watts, nobody normal understands that junk.

its simple

8 ohms = 180 watts

16 ohms = 90 watts

16 ohms is twice the resistance as 8 ohms, so you get half the power.

also less strain on the amp

[TheEAR]

Gil,

How correct

"This issue going down to 4 ohms is that the power supplies can't supply the current. Then the voltage sags.

However, the 16 ohms is drawing current probably without a sag. "

A good powerc amp should double its output from 8 to 4 Ohms.Most quality power amps are capable of this.I just have the Anthem Amp 20 on test and while not capable of doubling its output from 8 to 4 Ohms still will drive a 4 Ohms load with no trouble(tested on Klipsch RF-7's and Dynaudio Contour 3.3's passed my torture tests with no problems).

Any amp will drive 16 Ohms with no sweat,and 90 W RMS is not bad if you consider it should give over 200-300 watts on peaks.Plenty for most subs

TheEAR(s) Now theears

[justin_tx_16]

this is somewhat off topic, but why is it that the trend is that the higher end speaker headphones are, the higher the resistance is? thanks

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-justin

I am an amateur, if it is professional;

ProMedia help you want email Amy or call her @ 1-888-554-5665 or for an RA# 1-888-554-5665

Klipsch Home Audio help you want, email support@klipsch.com or call @ 1-800-KLIPSCH

RA# Fax Number=317-860-9140 / Parts Department Fax Number=317-860-9150

ProMedia 5.1 Placement Help s>

[lynnm]

Presumably anyone who is willing to try and understand the math is some sort of a freak? Go on back to your WWF show!!

The laws of physics will not be repealed in order to rescue anyone from having to use a calculator.

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It is meet to recall that the Great Green Heron rarely flies upside down in the moonlight - (Foo Ling ca.1900)

[justin_tx_16]

i am with you lynnm. i love to learn this kind of math especially since you can use it in your everyday life, here for example. we just finished studying this in my Physics AP class, now we are stating on magnetic fields and mixing those with electric currents, it is exciting!....err, that is not sad is it?

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-justin

I am an amateur, if it is professional;

ProMedia help you want email Amy or call her @ 1-888-554-5665 or for an RA# 1-888-554-5665

Klipsch Home Audio help you want, email support@klipsch.com or call @ 1-800-KLIPSCH

RA# Fax Number=317-860-9140 / Parts Department Fax Number=317-860-9150

ProMedia 5.1 Placement Help s>

[kenratboy]

Justin, I LOVE Physics! I can't say the same thing about chemistry, but calculus and physics are so much fun! The thing with me, is that I don't like overly abstract theories, like protons, neutrons, and electrons, and the next 15 chapters! But I can truely sink my teeth into some formulas and practical theories. In physics, we had to build a cannonpult among other things, it was all fun, chemistry just sucked for me, I learned NOTHING. My brain and my Ti-89 can do anything! I would like to know how much the Klipsch and JBL engineers really know about all of the stuff we learned in high school and college, I mean, are there computer programs that do all of the dirty work, or do they actually do math and thinking?

It was exciting in my first year of algebra to learn some of the formulas and methods, and then applying them to real life! I wiches mi englysh skyls dided as wells!