Softball question to anyone concerning cabinet setup

[MassiveBoogers]

This will probably be the easiest question today for someone to answer (and boy do I feel dumb for asking), but how do I connect my Dual Rectifier head to two 4x12 cabinets? I'm unsure of how to route the cables. I'm guessing it all has to do with the inputs/outputs on the cabinets as opposed to the outputs from the head itself... Thanks a bunch guys and please don't razz me too much

 

[formisano]

This will probably be the easiest question today for someone to answer (and boy do I feel dumb for asking), but how do I connect my Dual Rectifier head to two 4x12 cabinets? I'm unsure of how to route the cables. I'm guessing it all has to do with the inputs/outputs on the cabinets as opposed to the outputs from the head itself... Thanks a bunch guys and please don't razz me too much

If you're using Mesa cabs (or any other kind of 8-ohm cabs), simply plug the two cabs into the two speaker outputs on the back of your DR head. You'll now be runnig at 4-ohms. It is VERY IMPORTANT that you use actual speaker cables and not instrument cables.

The instruction manual that came with your amp has a ton of configurations for different cab combinations running at different ohms (some safe, not not so much). But the example you're asking about is simple as pie. Enjoy!

 

[MrMarkIII]

The Manual:
http://www.mesaboogie.com/manuals/2chRecto.pdf
Pages and pages of speaker hook-up info at the end.

 

[mrd]

Just for your reference, if you wanna know the overall load presented to an amp by connecting two or more cabs to it in this manner, use the following simple equation:

All the cabs' ohms multiplied together divided by all the cabs' ohms added together.

So if you have two 8ohm cabs, the equation would look like this:

8*8 / 8+8 which is 64 / 16 which is... 4. This is why you plug two 8ohm cabs into the 4ohm taps on your amp.

What if you had a 16 ohm cab and a 8 ohm cab (Marshall and Mesa)

16 * 8 / 16 + 8 which is 128 / 24 which is 5.3. You'd have to plug that into the 4ohm taps to be safe. My guess is you could also plug it into the 8ohm taps too but it would just run your power tubes quite a bit hotter. In my experience, Mesa amps are very rugged when it comes to mismatching cabs. I used to run my RK at a 2.6ohm load for the longest time and it worked just fine. Made short work of power tubes though.

You should check out the back of the manual though like the other guys suggested, there's tons of setups in there that you might not think of.

 

[MassiveBoogers]

The part that I'm confused about is this:

On the back of the head, I've got two 4-ohm outputs, two 8-ohm outputs and a 16-ohm output.
On the back of my Mesa cabinet I've got what appears to be two inputs and two outputs.

So, with that being said, how am I able to utilize all four speakers if I'm running two cables out of the head and only connecting one to the Mesa cab? I'm under the impression that there is no one stereo input, correct?

I'm still confused. But thanks guys for helping me with this.

 

[94Tremoverb]

The four jacks are two separate inputs for stereo (4 ohms each side), one input for mono (8 ohms), and one output for daisy-chaining from the mono input.

If you just want to run it as a single cab with all four speakers, connect to the 8-ohm mono input. (From the 8-ohm jack on the amp, if you're only running one cab.)

If you're running two such cabs, you can either:

Connect each cab from one 4-ohm jack on the amp (since the total load with two 8-ohm cabs is 4 ohms) to the 8-ohm mono input on the cab;

or:

Connect one 4-ohm jack on the amp to the 8-ohm mono input on the first cab, and daisy-chain from the first cab output to the second cab 8-ohm mono input.

Either way will work fine but the first is preferable because it's more reliable - in the second scheme, if the first cable fails or comes loose, the amp has no load, whereas in the first scheme both cabs are separately connected directly to the amp, and it would need a failure in *both* cables at the same time to do that. Only use the second scheme if you don't have a cable long enough to reach from the amp to the lower cab in a stack.