[sdiy] Speaker Impedance

[Rafael_Cohen at prusec.com]

Hey everybody,
Guess what... it's another newbie question!!

I have some schematics requiring 8 ohm speakers, and in some of my
DIY/scavenging I come across speakers of various other impedance, usually
higher than 8ohm.  Everything from 16ohms to 45 ohms... sometimes computer
speakers or speakerphones, etc...

My question is, what do I need to do in order to adapt the circuit to
speakers of different imedance?  Also, is there a simple way to test the
imedance of a speaker?

Thanks again,
Rafael