Speaker loads

[EETStudent]

I havent really dealt with speakers before necessarily, just plugged in and played. A couple days ago I received a cab I got off ebay fitted for 2 12s. I dont know the term for these, but it has the two connections for the speaker terminals, and both of those connections have taps off of them so you wire your two speakers however. What Im confused about is I have read that speakers do have polarity, and I have read that they dont have polarity. Anyways, I took my two 8 ohm speakers and wired them in what I thought was series connection for a result of 16 ohms. Sounded great, I felt safe that my impedences were matched, and all was well. Also a few days ago, I received my Silvertone OT from Weber and I was ready to install it. It requires a 4 ohm load, so I paralleled my speakers for this. It sounded like garbage. Really, really thin and the volume sort of fluxuated. I switched the speaker wiring back to what I had it at(16 ohms I thought) and then it sounded terrific. Basically, the same speaker setup produces positive results with both a 16 ohm load and a 4 ohms, and the opposite speaker setup produces terrible results at both loads. I must be misunderstanding something. Someone please eduacate me on speakers

[Enzo]

I have read that speakers do have polarity, and I have read that they dont have polarity.

Of course speakers have polarity, I have a hard time imagining someone telling you they don't. I CAN imagine someone telling you it doesn't matter which way you hook up a speaker - in other words that polarity doesn't matter. All by itself, you can make the case that one speaker sounds about the same connected in either polarity. But that is not the same thing as not having polarity.

If I connect a positive voltage to the + terminal of a speaker the cone moves forward. But if I apply a positive voltage to the - terminal of the speaker, the cone moves rearward. So obviously there is a polarity.

When more than one speaker work together, then all of a sudden polarity is extremely important. In a 4 x 12 cab for example, all four speakers must move the same direction together. otherwise the one moving forward will cancel out the sound waves made by the one moving rearward.

And that is what you have. WHen you wired the two speakers in parallel, they were wired out of phase - in opposite polarity - from each other, so one moved the opposite direction from the other, and they cancelled. The low end disappears, and the sound no longer sems to come from the speakers themselves, it has a spacy sound coming from somewhere the ears can't quite tell.

Speaker phase or polarity matters both in series and in parallel wirings. You lucked out and got the series in phase.

Series wiring: the hot wire from the amp goes to spkrA + terminal, then a jumper wore from spkrA - terminal to spkrB +. Then finally a wire from spkrB - to the ground wire of the amp.

Parallel wiring: connect both speakers together + to +, and - to -. Now connect the hot wire from the amp to one of the + terminals, and the ground wire from the amp to one of the - terminals. SInce both + are wired together, the hot amp wire can go to either one. Same with the ground wiring.

To test speakers for phase agreement, once they are wired up, touch a 9-volt battery for a moment to the speaker plug - don't leave it there, just momentarily. Each time you touch the battery to the speaker wires, the speakers should make a pop or thump sound. But if you watch, you will also see the cones move a little in one direction - either forward or rearward. Make sure all speakers move the same direction.

[6267]

I was taught a neat trick for checking speaker polarity quickly (it's not always marked, or on old speakers it rubs off or rust etc.). Take a 9v battery and touch it to the terminals. Whichever one makes the speaker go out with the positive connected to it is the positive terminal. Don't do this for much more than a second, speakers don't like DC. You can sometimes use an out of phase speaker in a very large setup to great effect, but in a 2x12 or 4x12 it's generally going to sound bad.