Can I Safely Run These Simultaneously???

chilipeppermaniac said:
I won't quote smitty, AMS, or Jethro, you guys can see their answers easily enough.
If I understand Robert's scenario right, he has 1- 2x12 cab at 8 or 16 ohms, and a 4x12 that goes 4 and 8 in the stereo or mono settings.

Maybe I can speak of my own experiences and y'all can clarify or clean up anything I say that is not accurate.

Let me start with, I have 0 0 0 ZERO, experience with a 2x and 4 x cab run together. BUT, I do have a particular experience with 2 4x12 Stereo/Mono cabs of different manufacturers. In this case, I have a Marshall 300 Watt G12/ 75 loaded cab that is operated as per these instructions. https://www.marshallamps.de/fileadm...nuals/Marshall-External-Cabinets-Handbuch.pdf
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NOW for where I learned that " guessing" is not a method. To ensure safe operation, one must confirm with a Meter the true output results. So follow me here. My 1960A cab is either 4 ohm Stereo, or 16 ohm Mono. To save from having a mismatch scenario like Robert did, I put BLUE Painter's tape over the 4 OHM Stereo side jack, and put the switch to mono 16 ohm. No possible way to plug a 16 ohm load into a 4 ohm cab setting that way.
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Does anyone make a non-conductive plug so I don't make a mistake again???

I'm really concerned I might have killed this head and it's just waiting to die at a live show (we play Halloween) and I'm nervous about it...
 
Thatbastarddon said:
Unfortunately the 2x12 set at 16Ohms is only going to feed one 16Ohm speaker per jack on the plate. It will be running in stereo mode, left and right speakers should be independent....so...yeah, best case scenario is rewire the 4x12 to 16Ohms, and pick one speaker from the 2x12, resulting in a 5x12 setup.
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Thanks Bdon, I was doing the mental gymnastics and having never dealt with 2x12's except in my Twin Combo, I really had to test my cobwebs on Speaker wiring schemes etc.

Another thing I remember is how Series, Parallel, and Series Parallel, Parallel Series are explained.



Here is an Amplified Parts explanation of the schemes,

Speaker Impedance, Power Handling and Wiring | Amplified Parts

www.amplifiedparts.com www.amplifiedparts.com
 
chilipeppermaniac said:
Well, it is YOUR gear, NOT HIS GEAR. IF ANYTHING, it should get treated BETTER than even you treat your own gear.
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I agree, @chilipeppermaniac

I guess I have just learned to not get upset about things like this. Honestly, I've quit bands over this in my past and I've had to learn to really cool down. I've always had a really hot, quick temper and It's caused me a lot of problems. So, there are amps that I will loan-out and several that I absolutely will not allow to go out of my sight.

After our October 10th show, they had loaded the huge trailer with all the band's gear, and had all the amps laying face-up on moving blankets. One of the guitar guys needed something from the front of the trailer, and I cringed as he walked across the edges of the amps/cabs to get to the front.

I'll tell you this....our bandleader has a custom made, purple tolex Germino Lead 55 and a pair of matching 4x12 cabinets - and it cannot be a cheap setup - and that poor rig gets treated roughly. Tears in the tolex, gouges and scuffs everywhere....I am just like OMG.

I would never, ever do that to one of my amps...but that's why ALL my gear is transported in my car and is set up and broken down by me and only me.
 
Robert Herndon said:
I agree, @chilipeppermaniac

I guess I have just learned to not get upset about things like this. Honestly, I've quit bands over this in my past and I've had to learn to really cool down. I've always had a really hot, quick temper and It's caused me a lot of problems. So, there are amps that I will loan-out and several that I absolutely will not allow to go out of my sight.

After our October 10th show, they had loaded the huge trailer with all the band's gear, and had all the amps laying face-up on moving blankets. One of the guitar guys needed something from the front of the trailer, and I cringed as he walked across the edges of the amps/cabs to get to the front.

I'll tell you this....our bandleader has a custom made, purple tolex Germino Lead 55 and a pair of matching 4x12 cabinets - and it cannot be a cheap setup - and that poor rig gets treated roughly. Tears in the tolex, gouges and scuffs everywhere....I am just like OMG.

I would never, ever do that to one of my amps...but that's why ALL my gear is transported in my car and is set up and broken down by me and only me.
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I understand. The differences you speak of are akin to YOU babying your Mustang or Truck, vs say how you or I would take a dirtbike out inthe desert or woods or track and get it all dirty. We may beat it up a little, but then we take care of it after that, so we can keep it in good shape to last us for future use.

My work trucks get mostly babied with easy driving, or careful braking etc, but I also walk all over the rails of the beds, load gravel and lumber and tools and all manner of stuff in em, haul stuff with trailers, cuz they are work trucks and not museum pieces. They came to me rough, they do not get much rougher despite adding hundreds of thousands of miles on em.
 
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Robert Herndon said:
Yep...its got the sticker...

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with what @Jethro Rocker and @ Amp Mad Scientist have kinda brainstormed, it IS possible for you to pull this off with some simple speaker rewiring, granted if your speakers are the right impedance. A series
Robert Herndon said:
He's a cool dude, they (the band in general) just don't seem to really take much effort in preserving the finish of their gear. Maybe I am too picky....
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I got a couple little pings in my guitars from over 20 some odd years but nothing major. My amps look brand new, nearly 20-25 years later. I try like hell to preserve stuff and i hate when someone abuses things
 
Clockworkmike said:
with what @Jethro Rocker and @ Amp Mad Scientist have kinda brainstormed, it IS possible for you to pull this off with some simple speaker rewiring, granted if your speakers are the right impedance. A series
I got a couple little pings in my guitars from over 20 some odd years but nothing major. My amps look brand new, nearly 20-25 years later. I try like hell to preserve stuff and i hate when someone abuses things
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Rewiring will only give you 5 of 6 speakers so you are technically able to add 1 speaker to the mix.
 
Jethro Rocker said:
So you can run it at 16 ohm with 1 speaker only. Rewire the Jackson for 16 and you can run both to 8 ohms total. A sreies parallel switcher could change things, I didnt do the math on all the options with that.
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Just a thought, Why haul a 2x12 to only use one speaker, Robert is wanting a lighter load of things. I might suggest adding a 1x12 16 ohm speaker cab. Or instead of the 6 speakers, 4 + 2 x12's, If Robert does not want a 1x12, then add a 2x12 the same specs as his 2x12 and set the Ohms as if it were a single 4x12?
 
Thatbastarddon said:
I own and use one regularly. Mostly for use with bass amps, but occasionally with guitar setups.
I’m very familiar with its use, and find it to be an excellent tool. Fairly cheap too.
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So, can you explain the 'amp series' and 'amp parallel' inputs??? It says not to use both simultaneously??? What does the 'line out' do???

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Robert Herndon said:
So, can you explain the 'amp series' and 'amp parallel' inputs??? It says not to use both simultaneously??? What does the 'line out' do???

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Here is the manual. If you are runnjng series you add the imoedances as per chart on top of unit. 2x8 ohms makes a 16 ohm load. The reason @Thatbastarddon is saying use 2 of these is so you can run 2 cabs or sets of speakers series for a 16 ohm load for each of the outputs on amp so a total of 8 ohm load. . Additional outpit is just to run signal out to another device like anpther amp.

 
Thinking as I go.
He would still not have equal number of 8 ohm loads either way. Without adding somethjng. Rewiring still will not give him am 8 ohm load so impedance will not match. He can run 8 amd 16 in series but that is a very high impedance to run.
 
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