Marshall 4x12 and Mesa recto 2x12 .. best way to hook up?

[xscottx9]

What is the best way to run these 2 cabs together through a Roadster?

I have alot of options on the back ..

I have the Marshall 4x12(4,16 ohm) plugged into the 16ohm
I have the Mesa 2x12(8 ohm) plugged into the 8 ohm

The volume dropped ALOT! .. im sure there is a better way.

How does Petrucci have his plugged in? I see he has a similar rig..

thanks

 

[Russ]

I think you should be dropping the ohms by one half unless your amp doesn't follow the typical loading practices. By this I mean to say that you should plug the Marshall into the 8 ohm socket on the amp and the 16 ohm socket on the speaker cabinet. Then your 8 ohm Mesa cabinet should be plugged into your 4 ohm socket on the amp. This should get you close to the proper loading. I know that on my Mark IV if I use my Marshall cabinet (1960ax - 16 ohm) and my Theile (EVM-12L - 8 ohm) this is the way that I have to run it. It just makes sense this way. If you plug in 2 16 ohm cabinets you will use 2 8 ohm amp output sockets. If you use 2 8 ohm cabinets you will use 2 4 ohm amp output sockets. I don't think that your amp has a 2 ohm output socket so you will have to use the 16 ohm input to your cabinet because using the 4 ohm input would cause you to need to use a 2 ohm output socket if you used 2 speaker cabinets. With that in mind it would be difficult to try to run 2 4 ohm cabinets because you would need 2 2 ohm output sockets on your amp. If you are plugging your 16 ohm cabinet into a 16 ohm output jack with your 8 ohm cabinet plugged into your 8 ohm output jack then you are not properly loading your amp. Your transformer may be in danger. Try running your cabinets in the way I described above and see if that helps any. Worst case scenario, call Mesa and get it from the horse's mouth. They will tell you exactly how to configure your amp and speaker cabinets.

 

[allcountyfair]

you should plug the mesa 8 ohm into the 4 ohm input and the marshall 16 ohm into the 8 ohm input. That should work.

 

[scottkahn]

1. First off... you have a Marshall 4x12 and a Mesa 2x12. I'll assume it's the Marshall 1960, which is 16 ohm mono or 8-ohm stereo. The Mesa cab is 8-ohm mono.

With your Roadster amp, if you want to use both cabinets, you will be running each cabinet in mono.

As a result, for proper matching of the cabinets to this head, you actually have to connect the 2x12 8-ohm cabinet to a 4-ohm connector, and the 4x12 16-ohm cabinet to an 8-ohm output. This is actually illustrated in your Mesa/Boogie documentation and is the propper mismatch that works most efficiently with your amp.

2. Note that your setup is not at all like John Petrucci's. He is using the Road King, and the speaker connections are one of the fundamental differences between the Road King and its baby brother, the Roadster.

The Road King amps feature Cabinet Switching. In this amp, the 4x12 speaker cabinet would be connected to the 16-ohm output for Speaker A and the 2x12 would be connected to the 8-ohm output for Speaker B.

On each of the four Road King channels, a user selects whether output is sent to Speaker A, Speaker B, or Speaker A+B. This way, on one channel, you may like the sound of a 4x12 closed-back cabinet while on another, you prefer the vintage sound of a 1x12 open-back, for example.

All speaker outputs in the Roadster are effectively one output -- there is no cabinet switching option and thus you have to deal with speaker impedence mismatches such as with your two cabinets.

I hope this helped clarify things.

Scott
p.s. We'll talk about the few differences between the Roadster and the Road King in our review of the RK Series II amp publishing Sept. 1 at MusicPlayers.com.