I hate to sound like a damn idiot but the Marshall 1960A cab has a 4 and 16 ohm mono input, and a 8 ohm stereo input.
Now the 5150 II head is switchable to 4, 8, and 16 ohms.
And I know that If I ,say, I switch to 16 ohms on the head, I would have to match it to that cab at 16 ohms, and so on for the others....
It says when I switch to 4 or 16 ohms on mono it will give power to all four speakers.
If I switch to 4 ohms on stereo it will give power to just the the right set of speakers
and for 16 ohm stereo, it will power just the left set of speakers.

Now to my question...

What ohm should I set it to for example:
When playing in my room?
During band practice?
During gigs?
And when recording in a studio?
Last edited by Metal_696 at May 13, 2006,
for that cab, the 4 ohm and 16 ohm setting are both MONO, playing all 4 speakers

the only way it will be in stereo is if you use the dual 8 ohm setting.

You should probably just set your head and cab to 16 ohms and use that in all situations mentioned. I never use the stereo feature because IMO its kind of pointless to have stereo operation in one cabinet.
yeah I know there both mono, I said that. lol...

But Yeah I thought that Stereo might be used if your recording. I dont know if thats completley correct though...
for that cab, stereo just means the two left speakers and two right speakers are seperated.
Doesn't matter, as long as you match up. So if the amp is switched to 8 ohms, the cab should be too, and so on.
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
Lol yeah I know that. But whats the hole point of having different ohm inputs? Better sound quality? Louder? Quieter? maybe 8 ohm stereo input is for recording? I dont know. This is what im tryin to find out.
its so you can hook up one cab or two cabs, or different cabs to different heads. its just a flexibility thing.
The impedance seen at the input is going to depend on what speakers they used, and how they wired them together in the cab. The reason your amp has different ohm settings is so it can use different cabs easily, not really for tonal options.

For example, say you had (4) 8 ohm speakers you wanted to use in a 4x12 cab:

You would wire the 2 pairs each in serial, which would give 16 ohms for each side of the cab (R1+R2). If there is an input for each side, the load impedance at each input would be 16ohms.

To connect those 2 speaker pairs together in a 4x12 config, you would wire them in parrallel (R1 x R2/R1 + R2 = 16x16/32 = 8), so you would see 8ohms at the one input for all 4 speakers. That's just one way to wire a cab, but you can see why that determines the impedance of the cab.
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