Is there a way to mix 1960A and SC212 cabs on SC20H?

saxon68

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There are a lot of threads with conflicting opinions all over the net.

I’ve got a 1960A cab that is loaded with 4 x 16ohm G12M greenbacks, wired for 16 ohms and the plate can also split them to 2 sides of 8ohms each.

Is there a way for me to use that cabinet and also use the SC212 cabinet that is wired 8 ohms with 2 V-type speakers?

If not I get it, I got the 2x12 for smaller stages and was just hoping I could use both cabs at rehearsal and break in all the speakers together as they’re all new-ish, under 8 hours playing at rehearsal volume for all of them.
 

Dogs of Doom

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quoted from another forum (TGP)

8 ohm + 16 ohm will measure at approx 5 ohms (5.333333333~ if you do the math) if they are parallel, so if your amp has a 4 ohm tap, you should be ok, assuming it's a decent amp and not some budget GC toy amp.

So, mixing them, you'll have a 5.3333333~ ohm load. You should be fine using the 4 ohm out...

Mixing 2 cab's like this is not always optimal, you be the judge, but you should be ok at 4 ohm, w/ those 2 cab's.
 

fitz

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There are a lot of threads with conflicting opinions all over the net.

I’ve got a 1960A cab that is loaded with 4 x 16ohm G12M greenbacks, wired for 16 ohms and the plate can also split them to 2 sides of 8ohms each.

Is there a way for me to use that cabinet and also use the SC212 cabinet that is wired 8 ohms with 2 V-type speakers?

If not I get it, I got the 2x12 for smaller stages and was just hoping I could use both cabs at rehearsal and break in all the speakers together as they’re all new-ish, under 8 hours playing at rehearsal volume for all of them.
SC20H has the 5 speaker jack configuration.
Santiago 2 x half load thing works.
1673803102742.png
16-ohm cab into one of the 2x16 jacks & 8-ohm cab into one of the 2x8 ohm jacks.
Two half loads on the OT.
 

RLW59

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Both ways described in the above posts are safe for your amp. (The method described by Fitz is a perfect impedance match, the one described by DoD is close enough that it's also completely safe.)

Running them both off the 4 ohm tap will send 2/3 of the power to the 8 ohm 212 and 1/3 of the power to the 16 ohm 412. So the 412 will add something to the overall tone but you'll mostly be hearing the 212.

The Santiago (the guy who designed the amp) method described by Fitz sends half the power to the 212 and half to the 412 so the 412 will contribute more to the overall sound.

Both are safe but give different results, so try both ways.

With only 20 watts you're barely tickling the speakers even when you just run one cab at a time. You may end up preferring one cab at a time rather than all 6 speakers together. But the amp won't be stressed by running more speakers -- the amp only cares about the total impedance -- so it won't hurt to experiment.
 

JeffMcLeod

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I have two MX212A cabs that come stock the same as yours (two 16ohm speakers wired in parallel for an 8ohm Resistance).

One thing I have done, is replace the speakers with two 8ohm speakers and wired them in series for a 16ohm R. That way you can use 1 cab at 16ohms or both in parallel for 8ohm R.

In theory the 5.333ohm thing should work, but not sure how you would plug them into the cab. I suspect you would need a 2-1 splitter to plug them both into the 4 ohm jack.
 

RLW59

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Another option is to run the 1960 in the stereo mode, using just two of the G12M's.

Plug that 8 ohm load and the 8 ohm SC212 into the "1x4, 2x8" jacks on the SC20H. Power will split equally between the 4 speakers and give a different tonal blend than either of the all-6 options.
 

RLW59

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Yet another thing to try is the 412 by itself in stereo mode, running just one pair of speakers from one of the SC20H's "1x8, 2x16" jacks.

That'll send 10 watts to each of the connected speakers pushing them a bit harder (instead of 5 watts to each when all 4 are running), and the 2 unconnected speakers act as passive radiators (being driven by the changing air pressure inside the cab) which can add some bass thump.
 

saxon68

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Thanks all!!

Really just wanting to break them all in if I can, I’ll adjust sound to taste and for gigs I’ll use one cab or the other, depending on the venue.

I’ll be playing this stage mostly, we don’t play out that often in this band. Venue has added a new building for bands / events. I think we will be opening for some nationals, and doing some of our own shows. Really looking forward to 2023, my last gig was pre-covid!!

1D690C13-3752-4E41-BB8D-0A60C50B770C.jpeg
 

Jethro Rocker

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SC20H has the 5 speaker jack configuration.
Santiago 2 x half load thing works.
View attachment 123264
16-ohm cab into one of the 2x16 jacks & 8-ohm cab into one of the 2x8 ohm jacks.
Two half loads on the OT.
This is perfect.
I have two MX212A cabs that come stock the same as yours (two 16ohm speakers wired in parallel for an 8ohm Resistance).

One thing I have done, is replace the speakers with two 8ohm speakers and wired them in series for a 16ohm R. That way you can use 1 cab at 16ohms or both in parallel for 8ohm R.

In theory the 5.333ohm thing should work, but not sure how you would plug them into the cab. I suspect you would need a 2-1 splitter to plug them both into the 4 ohm jack.
See above. Amp has 2x8 ohm jacks (4 ohm total). So could plug one cab into each jack.
Not sure why one would tho when Fitz suggestion above is just as easy to do and has no mismatch at all.
 

scozz

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saxon68

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Thanks!! That’s the gospel there, as far as I’m concerned :)
 
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