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stevel
03-09-2010, 11:12 AM
Ok, I think I'm finally starting to understand this series/parallel and ohms thing - I think.

But I have a lot of questions (feel free to addess any, all, or none :-) :

1. I have a cabinet with two 16 ohm speaks and they are wired positive to positive, and negative to negative.

The 1/4" cable coming to the speaks (it's an amp) is also positive to positive and negative to negative on the first speaker.

So even though it looks like a "series" of things - the cable wires to the first speaker, then wires to the second speaker, it's Parallel. Correct?

2. In Series, the wires make a "loop" where it goes positive to negative from the positive terminal of the amp (or connector) all the way round "through" the speaks (positive to negative) to the negative terminal of the amp (connector). Correct?

3. So this amp I have is Parallel, which means the two 16 ohm speakers have a total resistance of 8 ohms. Correct?

4. If it was wired in Series, you'd have 32 ohms (untenable of course)?

5. I have a small amp that is 15 watts into 8 ohms, so if I plug it into this 8 ohm cabinet, I will get 15 watts through two speakers now, rather than one. Correct?

6. The original amp that the two 16 ohm speaks are in has an impedance selector switch - 8, which it's on, but the other side says 4 (16) ohms.

How can it be both?

7. This amp has an extension speaker jack. If I were to plug in another 8 ohm load (a single 8 ohm, or a pair of 16 ohm, wired in series) what happens?

8. In Series, since the positives are attached to negatives, does it make "half" the speakers move the opposite direction - like as one moves forward the other moves back? Seems like this would cause a phasing problem so it's unlikely or is it just that when there's a current, it simply makes the opposite charge of the magnet, so the speaker moves out no matter what?

Sorry, mind is hungry today.

Steve

SatelliteAmps
03-09-2010, 01:05 PM
1. Yes.
2. Yes
3. Yes
4. Yes (some PA's use a 32Ω load)
5. Yes
6. Depends on the amp.
7. Usually a parallel jack, so the impedance goes down to 4Ω total, and internally the amp "should" switch to the correct tap on the output transformer.
8. Nope. The signal is flowing from positive to negative in all the speakers in series. First speaker A gets signal in from the + of the jack, to the + terminal of the speaker A and goes out the - to speaker B's + terminal, and out the - to the - of the jack.

stevel
03-09-2010, 07:06 PM
Thanks Adam.

I'll ponder the non "yes" answers some more, but at least I feel like I'm starting to get a handle on it.

Steve

just_one_more
03-09-2010, 08:03 PM
A way to visualize it is with batteries. A flashlight that has all the batteries end to end (+ to - to + to - etc. ) is a series configuration. Series and parallel is not just resistance (ohms), it is for pretty much anything electronic. Parallel is when you have all the batteries standing up parallel to each other, all the tops ( say +) connected and all the bottoms (-) connected together. Sources like batteries or pickups behave different when in series and parallel, but the concept is the same.