Ohmage ?

TamDB

Quick question, (which I should really know the answer to). I have two 8ohm cabs, both with in / out sockets, if I go into one, then out and into the other, does that give me 4 or 16 ohms ?
Like I said, I should remember this stuff, but my excuse is that i`m old and doddery now, (have I had me dinner ?)  

Alegree

Ignore me I have no idea what I'm talking about.

MartinB

There are a few exceptions (which are usually marked on the back panel), but most cabs with two sockets are wired with them in parallel, so you'd have 4 ohms. 

ICBM

What MartinB said. Almost all cabs with two jacks have them wired in parallel, so the total load is 4 ohms.

How to check if they're parallel: connect the amp to one cab, and play through it quietly - or just turn it up a bit further and listen to the background noise, if you can hear it. Plug a spare cable - not connected to anything else - into the other jack. If the sound doesn't cut out then the jacks are in parallel.

Alegree

Isn't he planning on hooking up the cabs in series? Does the fact that the speakers in either being in parallel affect things if the total is 8 ohms for each and he's hooking them in series? Genuinely curious. 

Cirrus

Alegree said:

Isn't he planning on hooking up the cabs in series? Does the fact that the speakers in either being in parallel affect things if the total is 8 ohms for each and he's hooking them in series? Genuinely curious. 

He may literally be plugging them amp->cab1->cab2 if you looked at them visually, but electrically it's still much more likely that the positive terminals on the amp and the speakers in both cabs are connected together, the negative terminals on the amp and the speakers in both cabs are connected together, and the only way for the signal to get from one to the other is through all the speakers in both cabs at the same time - ie parallel

Alegree

Cirrus said:

Alegree said:

Isn't he planning on hooking up the cabs in series? Does the fact that the speakers in either being in parallel affect things if the total is 8 ohms for each and he's hooking them in series? Genuinely curious. 

He may literally be plugging them amp->cab1->cab2 if you looked at them visually, but electrically it's still much more likely that the positive terminals on the amp and the speakers in both cabs are connected together, the negative terminals on the amp and the speakers in both cabs are connected together, and the only way for the signal to get from one to the other is through all the speakers in both cabs at the same time - ie parallel

So the out of the cab is wired onto the same coil end as the in? You learn something new every day. Thanks for the clarification

ICBM

It is confusing! Not helped by the labelling...

Normally the "in" and "out" labelling is unnecessary/incorrect and both jacks are simply connected directly to each other in parallel, with the speaker(s) connected to them as well, so in fact either jack can be the in or out, it makes no difference.

If it was actually a series connection then the in and out does matter, because the output has to break the signal path to insert the second cabinet between the input and the speaker - that's why you can check which it is by putting an unconnected cable into the 'output'.

TamDB

Hi guys, thanks for the replies. I probably asked the question wrongly as neither of the sockets are actually marked in, out or otherwise, but if I remember correctly there is no fancy wiring in there, the wires go straight from one socket to the same points on the other socket, then to the speaker, so i`m assuming that would be parallel ?, T

ICBM

TamDB said:

Hi guys, thanks for the replies. I probably asked the question wrongly as neither of the sockets are actually marked in, out or otherwise, but if I remember correctly there is no fancy wiring in there, the wires go straight from one socket to the same points on the other socket, then to the speaker, so i`m assuming that would be parallel ?, T

Yes.