4x12 cabinet wiring

[DalyTek]

I am replacing the speakers in my old Behringer 4x12 cab with Celestions and am completely lost now.
The cab is stereo/mono switchable.
The original speakers that were in it were each 4 ohm.
The back of the cab says in stereo mode, 8 ohm/channel and 16 ohm in mono.

The new Celestions are each 8 ohm.
When I test with my multimeter, the readings I get are:
stereo: ~12.7 ohm
mono: ~26.7 ohm

What the hell is going on?
Acording to the diagram I have, 4x4 ohm speakers should produce 8 oh/channel in stereo and 4 ohm in mono.
It says for my 4x8 ohm speakers, I should get 16 ohm/channel and 8 ohm mono.
Those readings make sense to me, but are not what I am getting.

The only thing I can think of is maybe the factory stereo/mono switch is wired up differently?

[straycat]

What are you going to do with the Jensens out of the Behringer cab?

[DalyTek]

Well, for now they are back in there, because I don't really want to run a 32ohm load on my amp.

[warlok]

I might have missed something, but... The cab with 4 each 4-ohm spreaker was 8/8 stereo (each side wired separately in series) or 16 mono (all 4 speakers in series). If you just swap the speakers to 8-ohm and don't change the wiring, each impedence rating is doubled. Hence 16/16 stereo, 32 mono (measuring with ohmmeter will have slightly lower measurements than actual impedence). You have to replace them with the same ohm rating speakers or rewire the cab. This is what I go by http://www.colomar.com/Shavano/4x12wiring.html , but the Behringer switch seems not to be wired the same as the switched diagrams. Yours must be all in series, those diagrams are parallel and series/parallel.

[1337storm]

You can either wire the speakers in series, in parallell or in series/parallell.
Of course you get different impedance for each type of wiring.
Also when you you meassure with a multimeter you are not meassuring impedance but
resistance and the resistance is allways a bit lower than the actual impedance.
There are numerous pages on cab wiring, but here is one : http://www.colomar.com/Shavano/4x12wiring.html

[Hellbat]

Speaker Ohms aren't resistance, it's inductance. A multimeter is going to measure resistance, not inductance.

Looks like it was wired in series originally. If you wired 2 pairs in parallel it would be a similar end result. Two 8 ohm speakers wired in parallel = 4 ohms. So one parallel pair per side wired in series for mono would total 8 ohms.

So with those speakers you are looking at either 16/32 or 4/8 operation depending on the wiring configuration. Putting a higher impedance load on an amp (within reason) isn't going to be harmful to it, but going under can cause bad things to happen.