Hey, I have been searching the forums and the internet for something to explain all of the impedence and wiring that goes into getting sound out of a head and cab. I haven't really found anything that explains it fully, atleast to where I understand it totally...so:

What I do know; series and parrallel circuits, how the ohms, watts, and voltage work in them (thanks to highschool physics)

What I don't understand is mono/stereo or about wiring between a head and cab...and I am looking at buying the bugera v55 HD and possibly the Bugera 212V-BK 2x12 Guitar Speaker Cabinet and would like to know how many watts I'll get out and how else I could wire it how I'll be able to add more later without breaking it.... anyway; so you don't have to look them up here is the Wattage, resistance and other stuff I don't understand for the amp and cab:

THE HEAD V55 says it has a switch for 4, 8, and 16 ohms and it's a 55watt amp

the cab says it has 140 Watts of power handling
Versatile 4/16-Ohm mono or 2 x 70-Watt, 8-Ohm stereo configuration

I want to understand what the 4/16 ohm mono is and then the 8ohm stereo is....I thought mono = series and that stereo = parrallel?? Also difference of mono and stereo, how I can add more speakers, change speakers

please let me know where I am confused and any other information, diagrams help..

Danelectro 1959 reissue

Quote by G.Krizzel
Music is just wiggly air. Accept it or leave it.

Also please visit this thread and help me tab out an album!!!
Last edited by 801Current at Mar 21, 2011,
Ok. The 4/16 simply means that your cab can be configured for 4 or 16 ohms as a mono speaker. At that impedance, it will handle 140 watts.

If you want to use it in a stereo configuration, each speaker will handle 70 watts at 8 ohms. In order to use it for stereo, your head would have to have stereo output capability, or you'd have to have two heads.

What this tells me is that each speaker is rated for 8 ohms impedance. In mono, the speakers can be wired in parallel or series. In series, the two speaker impedances add to give us 16 ohms. In parallel, the math stuff tells us that we'll end up with 4 ohms impedance.

Therefore, the amp you want to buy is mono. This is a whole different topic, but you can safely set the head to 4 ohms and run the cab at either 4 or 16 in mono. Or, you can configure the cab for stereo operation and run 1 speaker, which is 8 ohms. The key here is that the head always matches the cab impedance OR the cab runs at a higher impedance. For example, the head is 4 ohms and the cab is 4, 8 or 16. Never run the cab at less impedance than the head. Bad things happen - you let out the magic smoke.

Quote by KG6_Steven

Thank you very much, it makes a lot more sense, and if it's not too bothersome maybe just a few more questions I think I'll have everything I need

If the cab is set to either 4 or 16 ohms it will handle the same 140 watts? (as mono)
Like you said each speaker is 8ohms of resistance so if they were wired in series they would produce 16ohms and in parrallel 4ohms so then I don't understand how they can both still handle 140watts

EDIT: also the power coming from the head will stay the same going through the cab right?

and I just noticed the cabinet has next to it 212V...what does this have to do with anything?? :-/

would I use 212V in the equation of V=IR to find the Wattage that the cab can handle
so..212=I(4) and 212=I(16) and that would give me the wattage it can handle?

sorry for the bombartment..
Danelectro 1959 reissue

Quote by G.Krizzel
Music is just wiggly air. Accept it or leave it.

Also please visit this thread and help me tab out an album!!!
Last edited by 801Current at Mar 21, 2011,
Sorry for the late response. It really doesn't matter if the cab is set to 4 or 16 ohms, you're still able to handle 140 watts. Where it really matters is what's coming out of the head. As you change the head's impedance, the the power output will change. Typically, as we increase the impedance (higher number) the power output decreases. As long as we don't put more power into the cab than it's rated for, we're good. What do I mean by that? In other words, it's entirely possible to connect a head with 500 watts output to a head that's only rated for 50 watts. As long as we don't produce more than 50 watts, everything is good.

So, you can expect the cab to handle 140 watts as long as it's set to mono mode. Once you set it to stereo, then you're only good for 70 watts. In stereo mode, the impedance is 8 ohms per channel.

The 212V is nothing more than the model number of that cab. As such, it really means nothing more than 2 12" speakers. That's why you'll frequently hear cabs and combos labeled as a 112, 212, or even a 412. The first number refers to the number of speakers, while the second refers to the speaker diameter.

Don't worry about the bombardment. That's why we're here. If you have any more questions, just ask.
Thanks, I guess it's all a lo simpler than I thought

Thanks again, peace
Danelectro 1959 reissue

Quote by G.Krizzel
Music is just wiggly air. Accept it or leave it.

Also please visit this thread and help me tab out an album!!!