Cab Ohm to Head Ohm question.

darrenw5094

I just want to be sure about the connections here. I usually use combos, so this would not be an issue, obviously.

How exactly do i connect the head to the 2x12 cab. The two Celstions are both rated at 16Ohm.

eoin5

Their idea of left and right is confusing?! Anyways the connection with 8ohms mono connection on the cab to the top middle on the head makes most sense to me.

Welease

For mono, it looks like you use the top middle socket (1x8ohm) on the amp connected to the mono (marked left) (8 Ohm) connector on the speaker.
For stereo, you use the top and bottom middle sockets (2x16Ohm) connectors on the amp, connected to both the left 16Ohm and right 16Ohm connectors on the speaker (i.e. use 2 cables)..

The manual should have the specific information, as it's worth checking to be 100% sure.

Eoin Madsen

The amp doesn't do stereo, so just connect the 1x8 on the head to the 'left' on the cab, and all will be as well as can be.

darrenw5094

Eoin Madsen wrote: »

The amp doesn't do stereo, so just connect the 1x8 on the head to the 'left' on the cab, and all will be as well as can be.

If the amp doesn't do stereo, then what is the output jack under that one for?
2x16 and 1x8??

I was on the Marshallamps forum and the tech heads on there are all over the place too.

FarmerGreen

Does the cab have a mono/stereo switch?
On the ones I've seen, the left jack goes to the left speaker,
right jack to right speaker, when switched to stereo.
Switched to mono the speakers are connected in parallel and fed from the mono/left jack.
So the two 16 ohm speakers are now effectively 8 ohms.

darrenw5094

FarmerGreen wrote: »

Does the cab have a mono/stereo switch?

Nope. Just the 2 inputs. The pic is above.

FarmerGreen

OK, they may have used a switched jack socket.
Connect the 1x8 ohm jack on the amp to the mono 8 ohm input jack on the cab.
Give it a twang and listen to make sure both speakers are working.

Eoin Madsen

darrenw5094 wrote: »

If the amp doesn't do stereo, then what is the output jack under that one for?
2x16 and 1x8??

It's just a parallel output for using a second cab. It's an 8 ohm tap from the OT, if you put two speakers on it in parallel, they have to be 16 ohms each to match.

There's nothing unusual about this situation.

120_Minutes

amp output 1 x8ohm (top middle in the pic) to cab input mono 8 ohm (right side in pic)


job done.


OR you COULD take two outs from the 2 x 16 to both inputs on the cab. nothing really to be gained unless your amp has built in stero effects and even then you'd only notice the stereo effect if you were a foot in front of the cab

Eoin Madsen

Ahhhh!

Stereo means two separate signal paths, and two separate poweramp stages. That picture shows a 4 ohm, 8 ohm, and 16 ohm tap from a single output transformer. The cab does stereo, the amp does not.

darrenw5094

Eoin Madsen wrote: »

Ahhhh!

Stereo means two separate signal paths, and two separate poweramp stages. That picture shows a 4 ohm, 8 ohm, and 16 ohm tap from a single output transformer. The cab does stereo, the amp does not.

So does the 2x16Ohm thing work from the amp to 2 inputs of the cab. Or is it ONLY one speaker cable between the amp and cab?

eoin5

darrenw5094 wrote: »

So does the 2x16Ohm thing work from the amp to 2 inputs of the cab. Or is it ONLY one speaker cable between the amp and cab?

Its not only, but it looks like one lead should do the job.

Eoin Madsen

darrenw5094 wrote: »

So does the 2x16Ohm thing work from the amp to 2 inputs of the cab. Or is it ONLY one speaker cable between the amp and cab?

They're both exactly the same. One way will require you to use an extra speaker cable to no advantage at all.