speaker impedance question

[spuds]

Hi,
I've got this Marshall JTM60 and on the back it has two speaker jacks
1) 16 ohm internal speaker
2) 16 ohm external speaker

Now does that mean that I can plug another 16 ohm cab into the external speaker jack? But if I do that, then the transformer would be faced with a 8 ohm load (two 16ohm loads in parallel) instead of the 16ohms it has now with just the internal speaker.

Or does this mean that if I connect and external cab, i must disconnect the internal speaker?

Thanks

[y2stevo]

Re: speaker impedance question

I would definitly think that if you have the internal speaker connected you can add another 16ohm cab to the external socket aswell....

When you say the one for the internal do you mean that there is 2 outputs and one already has a cable going from it to the speaker??

[spuds]

Re: speaker impedance question

Yeah
It has two jacks and the internal speaker is already connected to one of them

[JumpMarine]

Re: speaker impedance question

I don't know about the JTM, but with the JCM 600 the load can't exceed 8 ohms. So, with the present set up it has one 16 ohm plugged into the internal jack and another 16 ohm ext cab plugged into the ext jack. This is safe. What I want to know is how the 4x10 cab is wired to not exceed 8 ohms?