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damage from wrong impedence?


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It doesn't make any difference to the speaker what the amplifier rating is as long as the maximum power rating of the speaker is not exceeded.

Driving a lower impedance than the amplifier is designed for can damage an amplifier.

Driving a higher impedance than the amplifier is designed for will result in the amplifier not being able to deliver its rated power.

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Just to, uh, amplify a bit... Rolleyes.gif

In general, when we're talking about solid state receivers or amplifiers, a speaker with a low impedance (like, 4 ohms) is tougher on the amp than a speaker with a higher impedance (like, 8 ohms.)

If someone rates their amplifier at some amount of watts into 8 ohms, you don't know whether the amp will have any trouble if you hook it up to speakers that have a lower impedance. It might work fine; it might overheat quickly, or it might not be able to play very loudly. You don't know.

On the other hand, if I rate my amplifier at some amount of watts into 4 ohms, or even lower (2 ohms), I'm telling you that hooking up difficult to drive speakers with a low impedance will not cause my amp any problems.

So, hooking up speakers with a higher impedance than your amp or receiver is rated for will almost always be a completely benign match. Hooking up speakers with an impedance lower than your amplifier or receiver is rated to drive is not usually a good thing.

One other point. Speakers do not have a linear, or flat, impedance as the frequency changes - they will be a lot higher than their averate values at some point, and lower at others. IF you connect two pairs of speakers in series with each other, you increase the total impedance the amp sees. If, however, you connect them in parallel, you REDUCE the impedance the amp sees, and if we're talking two pairs of identical speakers, the portions of the frequency where the impedance is at a minimum will overlap, and you can get some dangerously low values. Caution is urged. Don't hook up a bunch of speakers in parallel with each other and drive the dickens out of the them right away. Start with lower volumes, and make sure your amp is not overheating or having obvious (id, audible) difficulties before you crank em up.



Music is art

Audio is engineering

Ray's Music System

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Now Ray, I was really trying to avoid bringing up the issue of fluctuating impedance with frequency. Now you went and muddied up the watersSmile.gif

He's right though. But it's better if you don't think about. Just know that if a speaker is rated at 8 ohms, it mostly is, even though is may dip down to 4 ohms or lower at a certain frequency. It's usually only for a mirco-second though.

This idea of wiring two sets of speakers in 'series' or 'parallel' is more applicable to us old hippies who used to stack our 2 sets of Advents and drive 'em until our receivers caught on fire.

Think of wiring 2 sets of speakers in parallel as being the normal way of doing it. You stack two speakers, hook'em up to the left channel, then grab the other two, stack'em, and hook'em to the right channel. That's parallel. Doing this with 2 sets of 8 ohm speakers changes the impedence to 4 ohms.

'In series', you hook up one set of speakers to the reciever as you usually do, but then you do something really different with that 2nd set. This works best if you keep the extra speaker used for each channel close to the first one -- or else you will have cable everywhere.

You use another speaker cable (usually a short jumper like a foot or so), and connect the extra speaker directly to the connectors on the rear of the speaker that is already connected to the receiver. You do the same thing for the other channel and like magic, you now have two big ole 8 ohm speakers.

You could wire your KG's this way -- but you would only have about 30 wpc. It would however be easier on your amp, and maybe 30 watts might be enough.

At any rate, you can also go ahead and just hook them up to the spring clips on the back of the sub, which would be in parallel -- and run them at the 4 ohm impedance your amp normally sees, but like Ray said -- be careful. Don't drive it to loud and get that receiver.




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This message has been edited by deang on 06-23-2002 at 10:51 PM

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