2-Amp Setup into a Road King Cab, Thoughts or Opinions?

[singsinthetimber]

So I have two amp heads that I started using and to help with portability and to save space, I've been thinking about switching to one cab for both. In particular a Road Kind 2x12 or a Road King 4x12.

I was thinking about using my Lone Star on the open-back side and my Stiletto on the closed-back side. I've looked through the forum and haven't seen anything addressing this type of setup, but I might have missed something. Does anyone have any opinions, thoughts, or ideas on this type of setup? I live in Montana and we're quite rural here, so I'm unable to try out a Road King cab at the local music stores. Also, I'm not really interested in using a Radial Headbone, in the event that I want to mix the two amps.

Any help would be great! Thanks!

 

[BostonRedSox]

Can't do it. Mesa strictly has reasons why this isn't okay. I get that it seems like it would be, you know, with the fact that you can run either side of the RK cab separately or in stereo.

Sorry I can't give you the specifics. All I recall is that it is a definite no-no!

 

[rocknroll9225]

Can't do it. Mesa strictly has reasons why this isn't okay. I get that it seems like it would be, you know, with the fact that you can run either side of the RK cab separately or in stereo.

Sorry I can't give you the specifics. All I recall is that it is a definite no-no!

I'm not calling you a liar, but I can't imagine what could possibly be stopping someone from running it this way. If you run the RK 4x12 in stereo, you'd basically get a V30 closed back 2x12 (120 watts) and a C90 open back 2x12 (180 watts). Both sides would be at 8 ohms and could handle a 100 watt amp by themselves. Just make sure nothing's plugged into the mono input.

I would advise against getting a RK 2x12 for this purpose unless you don't want to run either amp on 100 watts. You could do it, but I'd be careful about cranking it up too loud.

 

[domct203]

If indeed Mesa says that is a no-no with the RK 4X12 Cab then it must be something specific to that cab. :?

I know for a fact that with the Recto 4X12's each stereo pair of speakers are electricly isolated with nothing in the Mono In jack, essentially being two separate speaker arrays in one cabinet.

On occasion I will run my Roadster stereo or W/D/W using a Recto 2:100. When I asked Mesa if it was safe to run the 2:100 in stereo using one Recto cab, I was told yes, that is what the stereo inputs are for.

Dom

 

[singsinthetimber]

I think I'll give Mesa a call and ask them about the RK cab. I thought it wouldn't be a problem but it looks like I should just check with them and report back with what they tell me.

I have a Recto 4x12 that I had been thinking about trying to split for two amps, two on the left for one amp and the other two on the right for the other amp. Dom, are you saying that I could use my two amp heads on the 4x12 cab I currently have without having to do any rewiring?
Thanks!

 

[khingpynn]

I have a Road king cab and I cannot see a reason why it would be a no no... the wattage should be compatable as should be the ohms... it's essentially two cabs in one... use the propper input jacks ( 8 ohm A and B ) and dont plug anything else into the cab... done. Once you hear from Mesa let us know what they say.

cheers
Craig

 

[domct203]

I think I'll give Mesa a call and ask them about the RK cab. I thought it wouldn't be a problem but it looks like I should just check with them and report back with what they tell me.

I have a Recto 4x12 that I had been thinking about trying to split for two amps, two on the left for one amp and the other two on the right for the other amp. Dom, are you saying that I could use my two amp heads on the 4x12 cab I currently have without having to do any rewiring?
Thanks!

If the Recto Cab is all original wiring then yes, one amp each into the 4 Ohm stereo inputs is fine. I've run mine that way with the Recto 2:100 with no issues at all. Just make sure nothing is plugged into the Mono In. To double check the integrity of the stereo hookups, plug one amp into one of the stereo inputs and confirm that sound only comes from one vertical pair of speakers. Repeat with the other stereo input to confirm sound only comes from the other vertical pair. If that test checks out good you should be fine.

Please post Mesa's reply to you RK cab question.

Dom

 

[BostonRedSox]

Please do post your response. The person I spoke to at Mesa was a guy named Tien. We were chatting one day about cabs (I called to ask for some general information) and told him I planned on running two different heads into one Road King cabinet. He told me it was a no-no and that they didn't design the cab to run like that. He also told me I could damage my amp in the process. You know what -- I don't think I asked questions after that. I think I just accepted his answer and moved on.

Perhaps I'm wrong though. The logic makes sense. It made sense to me two years ago when I first contemplated it. Maybe he was mistaken or I didn't understand him? Or perhaps there IS something bad about going that route ... :?:

 

[madnova73]

does anyone have any specifics on this as to why or why not? i've recently purchased a rk cab and want to blend my peavey ultra plus and dual recto together. sorry for resurecting an old thread

 

[BostonRedSox]

yes, i would like to know more about this also!

 

[BostonRedSox]

I called and talked about this issue with Marcus. He stated that while the cab isn't designed to work with two amps, it can be done safely. His biggest thing was that there will be ground loop issues present when running both amps in the Road King cab.

 

[jpdennis]

His biggest thing was that there will be ground loop issues present when running both amps in the Road King cab.

+1. That makes sense.

Just my 2 cents, if I was going to try something like this I would use the 4x12 and isolate two pair of 12s then use a crossover cable when I want to run all 4. RMS power and the correct ohms would be the big key to this. Letting both amps use the same ground just doesn't sit well with me. But I am far from an expert on that. :mrgreen:

Having said that, how would the cab sound with two distinct amps pushing it? Even if you use the single cab with no issues on the electronics side I am curious about the sound and mike positioning for stage production.

Dennis

 

[dbone]

I looked into this as well and the problem stems from the imput jack using a common ground and the way it splits from mono to stereo when you insert a speaker wire in one jack or another. It can cause ground loop problems as well as bigger problems if any of the components fail inside the input jack. If you were to rewire the cab so that it had two completely independent jacks And wiring for each side then it's not a problem. Or at least that's the way I heard it from Mesa. Why that's any different from using a 2:90 2:100 or 295 in stereo I don't know but I'm sure there's an answer out there.
I don't know if the jack is different on the road king cab?

 

[madnova73]

what about re-wiring the cab to a more standard recto style wiring? or would it be the same issue witht the ground?

 

[singsinthetimber]

So I recently picked up a used Road King 4x12 cab to use with my Lone Star Classic and Stiletto Ace. (I had previously been using a Rectifier 4x12 cab.) I had to do some minor adjustments though, but it took all of 2 minutes. I unscrewed the input jack plate and snipped some wires connecting the "A" side and the "B" side. Works fine, I now basically have two 2x12s in one 4x12 cabinet, one open and one closed.

 

[screamingdaisy]

FWIW, I think the Stiletto sounds better through MC-90s than V30s.

 

[singsinthetimber]

I'll be sure to try them with each set of speakers. Maybe even swap speakers from the open side to the closed side. Time to experiment.

 

[iceman]

I looked into this as well and the problem stems from the imput jack using a common ground and the way it splits from mono to stereo when you insert a speaker wire in one jack or another. It can cause ground loop problems as well as bigger problems if any of the components fail inside the input jack. If you were to rewire the cab so that it had two completely independent jacks And wiring for each side then it's not a problem. Or at least that's the way I heard it from Mesa. Why that's any different from using a 2:90 2:100 or 295 in stereo I don't know but I'm sure there's an answer out there.
I don't know if the jack is different on the road king cab?

I wouldn't expect a ground loop with the stereo power amps because both sides share the same ground/power source. With separate amps there are two separate grounds, thus the ground loop. Right?

 

[knotts]

I thank you for this post. I had been contemplating doing this with my Roadster and Lonestar head. I just figured I couldn't because my 4x12 only has a mono input.

Then, I realized that there is a spare 4x12 sitting right next to my set up at our rehearsal space and I have an A, B, Y switch...so I think the next logical thing to do is play through 2 amps and 2 4x12's simultaneously.

Anything I should know before I try this?

 

[singsinthetimber]

I don't know much about the inside workings of amps, I just like to play Mesas. But what I had to do when using my two heads is use one of the heads uses a simple 3 Prong to 2 prong grounding converter. At first I used an Ernie Ball Stereo volume pedal, I got lots of noise until I started using the converter. Nowadays in place of the volume pedal I use a Radial Big Shot ABY pedal, it's got all these switches for grounding noise but I still use the converter. I don't know if the converter is necessary but I still use it.