1200S ohm question

[Chovie]

My 1200S has a 16 ohm jack on the back and another jack that says "extension speaker-8 ohm". I run a 16 ohm 4 x 10 out of the 16 ohm jack.....I want to purchase a nifty Marshall 2 x 15 cab but it is also 16 ohms. Is it safe to plug that 16 ohm Marshall 2 x 15 speaker into the extension speaker jack and run it along with my 16 ohm 4 x 10? pardon my ignorance, I can never figure out this ohm stuff, no matter how many times it is explained to me and thanks for your help.

[Isaac]

Yes, it's safe.

Sunn sold the old 1200S with a 16 ohm speaker. It was expected that any extension speaker would be the same. By plugging in to the second jack, the output is switched from the 16 ohm tap of the output transformer to the 8 ohm tap. So, two 16 ohm cabinets are fine. If you want to run a single 8 ohm cabinet, plug it into the "extension speaker-8 ohm" jack.

[chovie]

thank you Isaac!!!!!
I am now gonna buy that Marshall 2 x 15. She is a beauty and its a steal of a deal from a buddy. Wahoo!

[chovie]

got a follow up question:

Would it be safe to run a bass thru the Sunn1200S 200 watt head and into the 2 x 15 200 watt cab alone? Ive heard its not wise to run bass thru guitar cabs because you might blow the drivers, but this is a 2 x 15 so Im wondering if I can cheat? I would disconnect my 4 x 12  guitar cab when doing this? Thanx again.

[Isaac]

I'd try it. Start with the volume failrly low, and turn it up. If you get as loud as you want with no ill effects of bad sounds, you're okay. Speakers usually sound bad before they give out, if it's due to excessive excursion, which is what driving guitar speakers with a bass can do. Listen for non-musical sounds, like the sound of the voice coil hitting the back plate. If you hear that, back off, you've gone too far. Also, make sure that the 2x15 is plugged into the 16 ohm jack if you're using it by itself, not the 8 ohm/extension jack.

[chovie]

Thanks again for your help Isaac!

[Isaac]

You're welcome.