A theory question

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AndyP

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When I want to plug in one rear loaded Diezel 4x12 cab, I have the choice between the 2x16 or 1x8 input of the VH4 top, because 2x16 = 1x8

And when I want to plug in a 2nd box, so I have to use the 1x8 for the first an the 2x16 for the 2nd box, right ?

On the box there are two sides. Side A 16 / 8 Mono and Side B 16

Why there's a Side B 16 ?

Or maybe someone knows a good website where I can read all that stuff about the theory.

Thanks in advance
 
I am not sure what you are asking ? :confused:

A lot of people are at NAMM ~ you may want to bump this a few days after that. :scared:
 
AndyP":2rf9nxml said:
And when I want to plug in a 2nd box, so I have to use the 1x8 for the first an the 2x16 for the 2nd box, right ?
Click to expand...

By 2nd box, are you referring to a 2nd speaker cab? If so, then your numbers, using 1x8 for the 1st and 2x16 for the second do NOT sound right, unless BOTH cabs (boxes?) are 16ohms. But it sounds, from your first sentence, that your Diezel cab is an 8 ohm cab. If that is the case, and you are using two speaker cabs with the same head, each cab would plug into a 4ohm (or 2x8) jack on the back of the amp.

I've not seen the rear of a Diezel cab :cry: but from what you said it sounds like Side A 16ohms/8ohms Mono Side B 16ohms means that if using the cab in stereo, each jack is 16ohms-i.e, plug a Herbert's 16ohm out into Side A, and a VH4's 16ohm out into Side B. When using one amp (other that a VH4S), you would plug the 8ohm out into the Mono jack on the cab.

I've seen websites that explain speaker loads, but don't remember them off the top of my head. You may want to try the Mesa Boogie site-The downloadable Dual/Triple Rectifier manual is pretty good at explaining how tube amps work, and has a good bit on safe/unsafe speaker loads.

If you can post your original question and explain what the load rating (in mono) of EACH cab is, I, or someone else, can help you figure out how to connect them to your amp. Also, are you intending to use the Diezel cab in Stereo mode-if so, that may change things a bit.

Like Stephen said, there are a lot of people at NAMM, so bumping the post in a few days may get you better answers: I'm not sure if I understood your original question, so sorry if my response may not be what you're looking for.

Rich
 
The simple answer is: use one speaker cable per cabinet and per amp.

An amp like the VH4 is mono, that means it has one amplifier, which needs to be connected to its cab via one speaker cable. You may connect more cabinets to it, but each with their own speaker cable. In this case, the speaker loads add up, as you already said: 16 Ohms twice makes 8 Ohms (because they're wired in parallel).
That's why you have multiple speaker outputs on a mono amp. Some people like half stacks, some people prefer having two cabs running.

As opposed to that, a VH4s is stereo, so it's basically two amplifiers in one housing, which need to be connected to their own cab with their own cable, respectively (think left and right speaker, like in your home stereo). BUT left and right can consist of more than one cab as well. And each one has it's own speaker output on the amp that is connected with ONE cable.

Here's where you may have mixed up something: you can use a cab like the Diezel in STEREO, too. One cab can be left and right speaker in one housing, for two mono amps (like 2x VH4) or one stereo amp (like 1x VH4s). In this case, your 4x12" is basically a double 2x12". If you use the Side B input, only the right upper and lower speakers will run. Check it out. Plug into the Side B 16 Ohms input and listen. Match the Ohms!
If you plug only into Side A/Mono, all 4 speakers will run as only plugging into the Side B input "activates" the speaker splitting.

That's why it's useless (but possible) to connect a mono amp with two cables.

I hope that worked out for you.

Jakob
 
Yes, I was writing about a Full Stack with a normal VH4 and two 4x12 Diezel Cabs.

So I have to plug in the first box to the 2x16 jack and the second box to the 1x8, right ?
Because the Diezel Cabs are on Side A 16 / 8 Mono and both should run Mono on Side A, I think.
 
What is "first box" ?
"Second box" ?
"2X16 jack" on what amp or cab ?
Is your amp stereo ?
Are your cabs stereo ?

I am sure the answer is simple but I can not figure out your question at all.

If both of your cabs are 16 ohm mono you want to plug both into 8 ohm jacks on the amp if it is mono.

If your cabs stereo split you want to use the 16 ohm mono ~ not the 8 ohm stereo jacks on the cabs.

You do not want to plug into a 16 and a 8 on the amp.

Two 16 ohm cabs are a 8 ohm load on the amp.

http://diezel.typo3.inpublica.de/upload ... ngl_01.pdf

Read page 9 of the manual and see if that helps.
 
Two Diezel 4x12 cabinets + One VH4 Top = Full Stack

There are 5 Inputs on the back of the VH4.

1x4
2x8

2x16
1x8

Now I want to have a Full Stack with two Diezel 4x12 cabinets. Do I have to plug one cab into the 2x16 jack and the other one to the 1x8 ?
 
The "inputs" on the amp you're talking about are outputs...if you have two cabs which have "8 Ohms mono" written on them, plug each one in one of the "2 x 8 Ohms" outputs on the VH4. Pretty self-explanatory, innit? ;)

Forget the "Side A" thing, that's for stereo use only.
Important is the "8 Ohm mono" inscription.

I guess both cabs are the same? Then they have the same impedance (in this case 8 Ohms). So why would you try to connect them to differently labeled speaker outputs on the amp?
 
"Now I want to have a Full Stack with two Diezel 4x12 cabinets. Do I have to plug one cab into the 2x16 jack and the other one to the 1x8 ?"

No ....Never.
 
I'm talking about two Diezel 4x12 cabinets, both are 8 ohm mono.


plug each one in one of the "2 x 8 Ohms" outputs on the VH4. Pretty self-explanatory, innit?
Click to expand...

The first cab into the 2x8 and the second cab into the 1x4 right ?

I need two outputs if I want to play a full stack.

The impedance of two 8 ohm cabs is 4 ohm right ?

That's why I have to plug the first one into the 2x8 and the second one into the 1x4 . . . because it's the same.

Same way when I just wanna play a half stack. So I have one 8 ohm box, and I have to use the 2x16 or the 1x8 output of the VH4 top, because of the 8 ohm impedance.
 
I think I big problem that always leads here is, that people actually think 1x4Ohms and 2x8Ohms are different speaker outs. They are NOT.

It goes this way for the VH4

Code: 
a     b     c
O  |  O  |
   |     |  O
O  |  O  |

Each one of the collums a, b and c is ONE speaker output.

a: use EITHER one 4 Ohm cab connected with one of the jacks OR two 8 Ohm cabs each connected with one of the jacks
b: use EITHER one 8 Ohm cab connected with one of the jacks OR two 16 Ohm cabs each connected with one of the jacks
c: use a 16 Ohm cab here
 
Thanks a lot for that, jaymz! I was too lazy to look up the configuration, but, utterly speaking, the questions were not easy to understand for someone that doesn't have the amp in front of him. It always sounded like using speaker outs with different Ohms to me.

So here's the final answer: you're right, connect the two cabs to the "a" outs in jaymz's graphic. Two times 8, as is written on them :-).

I'm not sure though, when you use a halfstack, if you can connect one cab to the output below the "8 Ohm" labeled one or if that one's only active when you use the upper one. Just use the 8 Ohms out. But they should both be the same. Time for a useless question to poor Peter now :-)

I hope this one's solved now.

Otherwise, buy yourself a combo :-))))
 
Thnaks Guys, but I think I've finally got it.

My question was simple in my view.

A Half Stack with one 8 Ohm mono speaker . . . . now adding a second 8 Ohm mono speaker . . . does the impedance change or not . . . now I've learned . . . it doesn't change.

So when I want to play a Full Stack I have to plug one speaker into the 2x16 jack and the second one into the 1x8 . . . both are at 8 ohm impedance . .. and the impedance doesn't change when I use 2 speakers.

That's all I wanted to know.
 
There are 5 jacks to plug in a speaker cable. Basically set up like below when you are looking at the back. When you connect two 8 ohm cabs, plug into both of the 4s. When you use two 16 ohm cabs, plug into both of the 8s. You can only use one 16 ohm cab, plug it into the 16.

4 8 16
4 8
 
I thing I have to quote myself again here :doh:

Jaymz82":2coopjcc said:
I think I big problem that always leads here is, that people actually think 1x4Ohms and 2x8Ohms are different speaker outs. They are NOT.

It goes this way for the VH4

Code: 
a     b     c
O  |  O  |
   |     |  O
O  |  O  |

Each one of the collums a, b and c is ONE speaker output.

a: use EITHER one 4 Ohm cab connected with one of the jacks OR two 8 Ohm cabs each connected with one of the jacks
b: use EITHER one 8 Ohm cab connected with one of the jacks OR two 16 Ohm cabs each connected with one of the jacks
c: use a 16 Ohm cab here
Click to expand...
 
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