I have four 16 ohm speakers and I'd like to find diagrams showing how to wire them in either four, eight, or 16 ohms.

[mforbzz]

I have a guitar cab with four Celestion Vintage 30 speakers that are 16 ohms each. I'd like to find diagrams showing how to wire them to change the impedance to either 4, 8, or 16 ohms, depending on which amplifier I intend to play through it.

 

[americanaudiophile]

If you put two identical speakers in series the impedance will 2x.
If you put two in parallel then the impedance will 1/2.
So if you want 4 ohms all the speakers connect in parallel. If you want 16 ohms you put pairs in parallel to get 8 ohms per pair. Then put each pair in series. The reverse works too to get 16 ohms.
Don't think you can get 8 ohms from four 16 ohm speakers but if you series one pair (32 ohms), parallel (8 ohms) the other and put them in parallel you can get about 10 ohms.
Here is a link for more info.
http://physics.bu.edu/py106/notes/Circuits.html