ROADKING AND CABINET CONNECTIONS

[kflow]

I have a Roadking combo and a genz benz 4x12. What is the best way to run that if I want both the combo speakers and the cabinet to run? The genz benz is a 300watt stereo cabinet with 2 16 ohm inputs for stereo and one of them being a mono for 8 ohms. I am also looking at getting a mesa cabinet. How should I run the two cabinets with out the combo speakers. Please help. I don't want to damage my gear.

 

[primal]

Go to page 38 and start reading from there. It goes through all the diffferent speaker hookup scenarios and spells out safe and unsafe mismatches.

http://www.mesaboogie.com/manuals/Road%20King.pdf

I have the same combo (provided yours is the original RoadKing and not a Roadking 2)

I love it, though I am considering switching to the head at some point.

For me I also run an external cabinet on the overdrive channels. I have a 3/4 back cab that sounds much thicker with distortion.

When I play clean, I use the combo speakers. The combo cabinet is much more open in the back and the cleans get much better clarity.

I do this simply by setting up channels 3 and 4 to use speakers A (the combo speakers), and I setup channels 1 and 2 to use speakers B.

 

[daveythomas]

So, lets say you have the combo speakers at 8 ohms and an 8 ohm external cabinet.

Do you calculate the loads independently for each output channel?

First, for simplicity, lets say you wanted everything to run all the time, would you hook both the speakers and external cab to output A using both 4 ohm jacks of channel A? It does say "use with two 8 ohm cabs".

Next, and what most people would probably do, lets say you wanted to run the cleans (ch1 and ch2) through the combo speakers and the overdrive (ch3 and ch4) through the external cabinet.

Would you hook the combo speakers into the 8 ohm jack of output A and the cabinet to the 8 ohm jack of channel B? Or, do they need to both be in the 4 ohm jacks?

Is the load calculated independently for each speaker output channel? Can you run two 8 ohm cabs on channel A and two 8 ohm cabs out of channel B?

 

[kflow]

Primal - Yeah I have read that in the manual. I just didn't get a warm fuzzy about hooking up my cabinet. I went ahead and hooked up my genz and the combo to speaker A output 4 ohms and it sounds so much better than when I use A+B 8 ohms and have both speakers on.

I am probably going to run my cleans through the combo only and when I get my other cabinet I will use speaker B 4ohms for both my 4x12's.

For now I will just run the combo and cabinet through speaker A 4ohms. I guess it is kinda like having a royal with cheese? anyway does what I am doing sound safe?

 

[primal]

If I understand you correctly you are playing with two seperate 8 ohm speaker connections plugging them both into the same channel on the 4ohm connections then yes, my understanding is this should be fine.

I found this nugget in the manual interesting

"SPEAKER OUTPUTS: (Continued) NOTE: Do not use the SPKR A + B selection when two 8 Ohm cabinets are each connected to
the two 4 Ohm OUTPUTS of each Speaker Output Bank. A 2 Ohm load puts an excessive strain on the power tubes causing them to
wear unusually fast."

Apparently these channels are not completely independent of each other.

Unless I am reading this wrong, I would assume this comment implies that if you are using an 8ohm cabinet on channel A and an 8 ohm cabinet on channel B and running them both at the same time, you should connect them to the 4 ohm output (I think).

 

[MrMarkIII]

The channels would be independent if they had separate output transformers, which, alas, they don't.
Just don't go down to, or below, 2 ohms (four, 8 ohm cabs in parallel) like the manual says.