Series parallel vs. Parallel series wiring in 4x12 cabs

grumphh_the_banned_one

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When reading the net i stumbled on this little gem, namely the claim that a 4x12 with 16 Ohm speakers wired to 16 Ohm will "sound different" depending on whether you wire it in
"Parallel - Series"
or in
"Series - Parallel"

Now, i have thought about it and eventually decided to draw it out, and all my feeble logic says that electrically the amp sees no difference whatsoever, so that there can be absolutely no difference in sound.

What say you?

Is this a myth spread by the electrically challenged or is it a real phenomenon?



The orange arrow is supposed to show the series connection...
 

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efstop

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I'm pretty sure my ears can't tell the difference, and I don't have a 4x12 to play with

BUT

For those who do and want to investigate it, here's a circuit layout that switches between the two:

SpeakerWiring.jpg
 

tolm

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I'm pretty sure my ears can't tell the difference, and I don't have a 4x12 to play with

BUT

For those who do and want to investigate it, here's a circuit layout that switches between the two:

SpeakerWiring.jpg

Really? I’d have thought that would just short out but I am certainly no electrical expert!!!

EDIT: Ignore my idiocy ... just looks a little weird drawn out like that but I see it now. :)
 

StudioFan

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I wired one of mine in series - parallel .

After some research, when you wire in parallel-series and blow a speaker , your amp can see a no load situation.

Not likely to happen but still , why run the risk of damaging your amp ?
 

grumphh_the_banned_one

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Really? I’d have thought that would just short out but I am certainly no electrical expert!!!

EDIT: Ignore my idiocy ... just looks a little weird drawn out like that but I see it now. :)
Despite your edit, perhaps this shows it better? :)

...but yeah, series-parallel connections can be tricky to get correctly at first glance.
 

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grumphh_the_banned_one

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I wired one of mine in series - parallel .

After some research, when you wire in parallel-series and blow a speaker , your amp can see a no load situation.

Not likely to happen but still , why run the risk of damaging your amp ?
This is wrong.
Even if one speaker blows there will be either two or three speakers still presenting a load to the amp.

The impedance will change though.

In the left side pic (P in S) one blown speaker would result in the other three still presenting a load - only it would be a load of 24 ohm.
In the right side pic (S in P) one blown speaker would result in two speakers still presenting a load - but this load would be 32 ohm.

Both scenarios are definitely not ideal, but still better than infinite resistance.
 

dspelman

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This is an OLD myth (dating back to almost the first 4x12), and one that's been pretty much debunked over the last half century these things have been around. There are *still* people out there who claim they can tell the difference. We've blind tested it at a few guitar shows (decades ago) and the ones who've made the claim have pretty much failed to correctly identify the difference.
 

crosstownblues

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As far as I can tell, the only reason to wire that way is if you have only 8 ohm speakers and your amp won't support a 2 ohm load. Series/parallel wiring results in a load equal to one speaker in the chain, whereas parallel wiring divides single speaker ohm rating by the number of speakers wired together.
 

ErictheRed

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As far as I can tell, the only reason to wire that way is if you have only 8 ohm speakers and your amp won't support a 2 ohm load. Series/parallel wiring results in a load equal to one speaker in the chain, whereas parallel wiring divides single speaker ohm rating by the number of speakers wired together.

No it's worse than that. Some people think that if you wire the same four speakers in these two "different ways," then they will sound different:

1. Put two speakers in parallel, then the other pair of speakers in parallel. Now wire those two networks of parallel speakers together in series.

2. Wire two speakers in series, then the other pair of speakers in series. Now connect the two networks of series together in parallel.


There is no test in the known universe, either theoretical or practical, that would allow anyone to distinguish between those modes of wiring (given the same length of the same wire, etc) if they were sealed inside a box that you couldn't look into. This a fundamental fact of electromagnetism.

The misunderstanding probably comes from some "expert" in guitar audio that can claim to hear differences in whatever and whatever, yadda yadda. But if a huge rock star repeats it, then it gets passed along as fact. It could also stem from a misunderstanding of how current propagates through a circuit. This can actually get a little bit complicated (there is drift current and diffusion current, etc...), but:

Think of a simple example where you have a single battery, two wires, and a lightbulb. You connect the positive terminal of the battery to a wire, that wire to one terminal of a lightbulb, and then the other terminal of the lightbulb is connected to the negative terminal of the battery. The light comes on! Many people think that the current comes out of the positive terminal of the battery, then flows through the light, then comes back into the battery, so that there is a sequence of events or a time delay between when the starting current gets to the lightbulb to turn it on. However, this is not so! What actually happens is that the electric field propagates through the wires at nearly the speed of light, so that ALL moving electrons, ALL charges begin to flow in a loop at the same time the instant that the circuit is closed.
 
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Splattle101

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No it's worse than that. Some people think that if you wire the same four speakers in these two "different ways," then they will sound different:

1. Put two speakers in parallel, then the other pair of speakers in parallel. Now wire those two networks of parallel speakers together in series.

2. Wire two speakers in series, then the other pair of speakers in series. Now connect the two networks of series together in parallel.


There is no test in the known universe, either theoretical or practical, that would allow anyone to distinguish between those modes of wiring (given the same length of the same wire, etc) if they were sealed inside a box that you couldn't look into. This a fundamental fact of electromagnetism.

The misunderstanding probably comes from some "expert" in guitar audio that can claim to hear differences in whatever and whatever, yadda yadda. But if a huge rock star repeats it, then it gets passed along as fact. It could also stem from a misunderstanding of how current propagates through a circuit. This can actually get a little bit complicated (there is drift current and diffusion current, etc...), but:

Think of a simple example where you have a single battery, two wires, and a lightbulb. You connect the positive terminal of the battery to a wire, that wire to one terminal of a lightbulb, and then the other terminal of the lightbulb is connected to the negative terminal of the battery. The light comes on! Many people think that the current comes out of the positive terminal of the battery, then flows through the light, then comes back into the battery, so that there is a sequence of events or a time delay between when the starting current gets to the lightbulb to turn it on. However, this is not so! What actually happens is that the electric field propagates through the wires at nearly the speed of light, so that ALL moving electrons, ALL charges begin to flow in a loop at the same time the instant that the circuit is closed.
Oh baby, I love it when you talk dirty, dirty science to me.
 

CB91710

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Yep... It's like tone cap between the volume pot and tone pot, or between the tone pot and ground.
There is no electrical difference. It's like switching the hot and fusing the neutral, vs switching the neutral and fusing the hot, vs switching and fusing the hot or neutral... except in this case there is no danger in one vs the other.
Running a jumper as diagrammed, there is no current flow through the bridge.

Now if you want to have some fun with series-parallel calculations, try this one.

Resistor-Puzzle.png
 

Side Burns

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when all those electron clouds pass through a circuit, you can almost imagine an electron stream passing kind of like a fluid. Electricity and fluids have Pressure/voltage, current/flow-rate, resistance/restriction. Electricity isn’t viscus so there are limits to the simile. But there can be things that happen that it may cause differences but maybe you would need a scope to see it. or maybe you can hear differences between the drivers. Idk
one way to find out.
Test it
 

ErictheRed

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when all those electron clouds pass through a circuit, you can almost imagine an electron stream passing kind of like a fluid. Electricity and fluids have Pressure/voltage, current/flow-rate, resistance/restriction. Electricity isn’t viscus so there are limits to the simile. But there can be things that happen that it may cause differences but maybe you would need a scope to see it. or maybe you can hear differences between the drivers. Idk
one way to find out.
Test it

It's been tested a trillion times by every freshman physics or electrical engineering student in the world. You can't detect a difference on a scope.
 

CB91710

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It's been tested a trillion times by every freshman physics or electrical engineering student in the world. You can't detect a difference on a scope.
But can you detect a difference in the Mojo? :laugh2:
 

grumphh_the_banned_one

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Yep... It's like tone cap between the volume pot and tone pot, or between the tone pot and ground.
There is no electrical difference. It's like switching the hot and fusing the neutral, vs switching the neutral and fusing the hot, vs switching and fusing the hot or neutral... except in this case there is no danger in one vs the other.
Running a jumper as diagrammed, there is no current flow through the bridge.

Now if you want to have some fun with series-parallel calculations, try this one.

View attachment 467603
You just made me waste an hour trying to solve this!!!! On a saturday morning, no less!!!! :mad2: *

To sort of solve this ihad to draw it out in my inept style (colours to visualize what was connected to what, kiddie style) and arrived at the pic below.
I simply assumed that the midlle resistors are basically in parallel in pairs - and only found out when i looked at the solution that there is a rule that says that an equal potential is the same as having a wire between those points - so i calculated 1/500 + 1/500 + 1/500 (inv) rather than adding up 6 1/1000 and inverting that.

...and since i omitted the decimals, i arrived at a wrong solution - but close enough for rock'n roll :D

* JK Actually, thx for this - i learned a little today as well :yesway:
 

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