Series vs Parallel

[CTC564]

Please explain the difference when connecting 8 ohm cabs to an amp

Which delivers better sound?

[billfitzmaurice]

Originally Posted by CTC564

Please explain the difference when connecting 8 ohm cabs to an amp

Which delivers better sound?

Since almost every amp has parallel connected outputs the topic is moot.

[Munjibunga]

Better than what?

If your amp is rated for maximum output at 4 ohms, using an 8-ohm cab will reduce the power available. Generally, 4-ohm cabs and 8-ohm cabs of the same brand and model sound the same.

[AwkwardLoudness]

A parallel setup subtly delivers better sound because each cab is delivered signal in the same manner. With series, the output signal runs through one cab before the other. Also, most solid state amps deliver maximum power at 4Ω.

[CTC564]

Ok...but is it better to run the amp at 4 ohms if it can handle that?

Amp to cab and then cab to cab

Or

Amp to cab x2

[AwkwardLoudness]

Amp to cab and then cab to cab

Or

Amp to cab x2

If the cab to cab connection is in parallel, then it really makes no difference. Either method is fine.

[CTC564]

I'm really sorry I'm having so much trouble with this and I really appreciate the help you given me these past few weeks....

But if I have two 8 ohm cabs and what to get max efficiency out of my amp that can handle 4 ohms, I should go amp to cab and cab to cab???

[Sneakypete]

If your amp has two speaker sockets they are already wired in parallel. Plugging one cab into each socket is exactly the same as only plugging in the first cab and then plugging the second cab into 'link' or 'thru' of the first cab. The difference in efficiency, if there is any, is microscopically small. If you have trouble visualising the difference between series and parallel think of it like this; a ladder has the rungs in parallel - think of the rungs as the speakers and the stiles or sides of the ladder as being the plus and minus of the amplifier output. Think of series wiring as being like the links in a chain - one end of the chain goes to the output plus the other end goes to the output minus. Analogies aren't always a good thing but at least this will give you the general idea.

[CTC564]

LOL...actually SneakyPete, that analogy worked for me...

Thanks to all for the info

[billfitzmaurice]

Originally Posted by AwkwardLoudness

With series, the output signal runs through one cab before the other.

That's not a series connection. It's still parallel unless the jacks in the first cab are specifically wired in series; none are unless you did so yourself.

But if I have two 8 ohm cabs and what to get max efficiency out of my amp that can handle 4 ohms, I should go amp to cab and cab to cab???

The difference between the two options is infinitesimal, unless the cables are in excess of fifty feet or so or you're using seriously under-gauge cables, as in 28 ga or lighter.

[Munjibunga]

Originally Posted by CTC564

I'm really sorry I'm having so much trouble with this and I really appreciate the help you given me these past few weeks....

But if I have two 8 ohm cabs and what to get max efficiency out of my amp that can handle 4 ohms, I should go amp to cab and cab to cab???

It makes absolutely no difference. The connections are electronically identical whichever way you do it.

[AwkwardLoudness]

Originally Posted by billfitzmaurice

That's not a series connection. It's still parallel unless the jacks in the first cab are specifically wired in series; none are unless you did so yourself.

I have a unique tube amp with four output jacks, i.e. two parallel pairs in series. It can run four 4Ω cabs with a total combined impedance of 4Ω, or a single 4Ω cab if a dummy plug is used (same deal with 8Ω or 16Ω cab(s)), but it can't properly run two 4Ω cabs in parallel since there is not a 2Ω tab. I can run two 4Ω cabs in series from the 8Ω tap.

Parallel cabs sound a tad more 'full' in my experience. The same goes for parallel vs. series wiring between two speakers in the same cab. It's not a huge difference, however.