Flat impedance curve?


Hi,

How big impedance intervals can speakers have and still be considered as "flat"? I have a pair of 4 ohm speakers (Isophon Galileo) that has a maximum impedance of 10 ohm at a certain frequency and dips to 2 ohm at another. Are these speakers flat?

Can I use these speakers together with an 4 ohm tube amp or is that not a wise choice?

/Jwal
jwal
You might find it that it might be a bit more complicated than that. It might be more beneficial to see a graph of the impedance, to see how and where the impedance varies. The phase angle can be just as important in considering amps for speakers. IMHO, what your proposing doesn't appear to be ideal.
2 ohms at 10000 Hz is not much of problem because there's not much amp draw there. 2 ohms at 100 Hz will be a problem for most amps.

I would be surprised if the maximum is 10 ohms for any dynamic driver getting near Fs.
Ngjockey, FWIW at Fs the impedance could be much higher than that; 20-40 ohms is not that weird if there is no port.