which socket?

[elysianfield]

Which is best to plug my 100w head into......

4ohm mono or 16ohm mono?

Cabinet is fitted with x2 8 ohm speakers...

So the difference is series or parallel wiring...

[jet66]

If you are asking if there is a difference between 4 and 16 ohm (with the speakers wired accordingly) I don't really hear it, myself. I've heard arguments that 16 ohm is better, and more from an electrical standpoint than from the tone aspect, but I can't say I hear a real difference. I have run my 4x12 at both 4 and 16 ohm on an Engl Blackmore, and just one time the 4 ohm config seemed to fart out, but I think I had jostled a power tube slightly loose. After some tweaking and twiddling, it didn't happen again.

[DonP]

Best to try either way. It is possible to have a slight tonal difference.

I use 16 personally in a 4x12. I can't remember why.

One thing though - with 2 speakers, wiring in parallel give you a safety factor if one of the speaker coils burns open. You'd have a load of 8 ohms, but still better than no load at all (assuming this is a tube amp).

[Bengal65]

Here's some good info:

http://www.colomar.com/Shavano/2x12wiring.html

[Dreamland_Rebel]

find out the cab's wiring and go from there.
series = 16ohms.
parallel = 4 ohms.

(if a + is wired to a - then its series. if its wired + to + and - to - it's parallel)

[elysianfield]

Best to try either way. It is possible to have a slight tonal difference.

I use 16 personally in a 4x12. I can't remember why.

One thing though - with 2 speakers, wiring in parallel give you a safety factor if one of the speaker coils burns open. You'd have a load of 8 ohms, but still better than no load at all (assuming this is a tube amp).

The cabinet has 2 sockets giving me the option of 4 or 16ohm in mono. The amp has every conceivable output you'd want, so i could use either single 4ohm out or single 16ohm.
So there is no difference running the tube amp at 16ohm or 4 ohm then? in regards to tone or efficiency? wouldn't the wattage of the amp differ?

[jet66]

wouldn't the wattage of the amp differ?

As long as the impedance matches, the wattage will be the same. The wattage would change if you were going from a 4 ohm out to an 8 ohm load, in which case you would lose roughly 1/2 of your wattage.

[Dreamland_Rebel]

The cabinet has 2 sockets giving me the option of 4 or 16ohm in mono. The amp has every conceivable output you'd want, so i could use either single 4ohm out or single 16ohm.
So there is no difference running the tube amp at 16ohm or 4 ohm then? in regards to tone or efficiency? wouldn't the wattage of the amp differ?

the wattage will be the same but the sound will not.
4 ohms will react like you are pushing the amp harder while 16 ohms will be slightly more tame and full bodied sounding.

[elysianfield]

the wattage will be the same but the sound will not.
4 ohms will react like you are pushing the amp harder while 16 ohms will be slightly more tame and full bodied sounding.

That is exactly the answer i wanted! cheers dude

Thanks to everyone else for their inputs