speaker cab question

[Chritar]

i have the vox v412bn cab, its back plate has a mono(16omhs) input and then two stereo(8ohms) inputs labeled input A and input B. and the apeakers are wired like this, except the stereo inputs are wired seperate to each side and the mono input just has a positive wired going to one side and the negative connecting to the other.

i just installed 2 v30s and 2 g12h30s. i put both the v30s on one side and the g12h30s on the other. they sound great. clear and the reverb and slight tremelo stuff comes out a lot more and note definition is superb 8D

my question though, is, would it be safe to have two speaker cables running from my amp to both the A and B inputs on my cab, and run it at 16ohms? or should switch the switch on my head to 8ohms? would it give it any more clarity?

[Vim Fuego]

Unless you have a stereo amp the safest thing is to run the cab in mono (16 ohm) and use the 16 ohm output on the head. If you use two sockets on the amp and two leads to the cab in stereo you'll need a pair of 8 ohm sockets or a 4 ohm socket and a split lead!
Jim
P.S.
Here are the sockets on my head

in your case you could put the cab into stereo and use the right hand pair of sockets one for each input A and B.

[Chritar]

my head only has two sockets, and it has an impedence switch for 16ohms and 8ohms, my guess is that i can run it at 16ohms impedence and hook up two cabs with 16ohms resistance, or if my cab has both sides running 16ohms, which its actually 8ohms per side on my cab...if i wanted to run it stereo, should i switch my heads impedence to 8 ohms? or leave it at 16ohms, i figure if its 16ohms it would give 8ohms to each side, not sure if thats how it works?

[Vim Fuego]

We really need to check the instruction manual of the amp, tell us what it is and I'll see if I can get any info... in the meantime...
From what you've said
1) The amp has an impedance selector switch for 16 or 8 ohm operation.

2) The amp has two identical sockets for speakers.

I would guess that you would use it like this:

One 16 ohm cab -> plug into either socket and set selector to 16 ohms

Two 16 ohm cabs -> plug each cab into each one of the sockets and set selector to 8 ohms (2 x 16 ohms in parallel wiring).

One 8 ohm cab -> plug into either and set selector to 8 ohms.

From your first post in stereo mode each side of your cab (A & B) has an impedance of 8
ohms. If you wanted to wire it up as if it was two independent cabs you'll need a 4 ohm switch on your amp. (When you have 2 cabs with the same impedance connected in parallel the combined impedance is HALF, as in the 2x16 example above).

Internally in mono mode the two halves of the cabs are wired in *series* which DOUBLES the impedance value(16 ohms).

If you really wanted to do what you want then I can give you the required changes to the cab wiring if that helps (you may need to get a soldering iron out!)

Still the best option, put the cab in mono and set the selector to 16 ohms and plug one lead from either socket to the mono input.

I hope this information helps, if not, ask again and I'll try to be clearer.
Jim

[Chritar]

it helps, the amp head im using is a vox ac100cph, what i was thinking isnt really a huge deal, i was just thinking it may sound more distinct that there were two speakers if i had stereo set up to both a/b sides. but with my head i dont think it'll work

[Vim Fuego]

Yeah, I can understand the reason for the question and in fact you may be right on the sound difference I don't know, but you'd need to rewire your cab sorry!
Jim