A question about impedance

[mchurch]

I have set of speakers set up with jumpers to allow for bi-wiring. The question I have is if the speakers are 8ohm with jumper, what would they be at the individual binding posts with the jumper removed? I am entertaining bi-amping with a 2 pair of Paramounts and want an idea of what kind of impedance they will have.


Cheers;

Mike C

[porcupunctis]

I would check them with an ohmmeter.  The reading you get will be lower than the actual impedance but it will help you sort it out a bit.  For instance, if you measure an 8 ohm speaker this way you may only read 6.9 homes or so.  A 4 ohm speaker will read around 3 or so.

[fullheadofnothing]

Impedance is a bit more complicated than DC resistance, especially when you're talking about speaker impedance, which varies with frequency. Impedance listed is nominal, which means that an "8 ohm" speaker might be 2 ohms at some frequencies, and 20 ohms at others, and when it all gets averaged out, it's 8.

Here is a link that will help you measure the impedance and various frequencies, which is a fun little afternoon project. It may turn out that, for instance, your bass terminals average out to be substantially lower in impedance than your treble terminals. Then you could wire one amplifier to 4 and one to 8. Best of both worlds!

http://db.audioasylum.com/cgi/m.mpl?forum=bottlehead&n=36837&highlight=voltage+method&r=&session=