Making a 8 ohm load with (4) 4ohms speakers?

Question

I have 4 speakers that are 4 ohms each, and I want to wire them all together to make one large speaker, but I need the final ohm load to be either 6 or 8 ohms. Is there a way to wire together these (4) 4ohm speakers together so I get either a 6 or 8 ohm load?

I've looked at all of the combinations of parallel and series circuits I could form with these, and have only come to a load of 4 ohms or less or 16 ohms. Is there a way i could use a resistor or something of that nature to get an 6 or 8 ohm load? (or perhaps I missed a wiring combination that would make this load) I need to be at 8 or 6 ohms beacause I do not want to fry my amp.

Answer 1

If you connect your amp to one speaker, the ohms rating is equal to that speaker's ohms rating. An 8 ohms speaker would have a rating of 8 ohms.

If you wire two or more speakers in series, you add the ohms rating together to get the total ohms. I know what series & parallel wiring is from grade school science. It's hard to describe without diagrams, so I'll keep my description minimal. You can refer to the diagrams in the articles from my bibliography if you need more help.

My grade school science book had the example of christmas lights. When you wire the lights in series, you connect the + terminal of one light to the - terminal of the next light. The electricity flows through one light, and then on to the next. If any of the lights goes out, or any of the connections breaks, all of the lights go out. The connection is broken.

This increases the total resistance, reducing the total acoustical ouput. That is, because the electricity has to flow through each speaker one at a time, each speaker adds it's resistance to the whole. The formula is as follows:

Speaker A + Speaker B = Total Ohms Rating
8 Ohms + 8 Ohms = 16 Ohms

Two 8 Ohms speakers wired in series will have a total rating of 16 ohms.

Answer 2

Obviously, 4 4-ohm speakers in series is 16 ohms.
Two 4-ohms in parallel and the other two in series is 10 ohms.
Two in parallel, in series with two more in parallel is 4 ohms.
Three in parallel with one in series is 5 and 1/3 ohms.
4 in parallel is 1 ohm.

Here's a possibility: put 2 in series, giving 8, then put the other 2 in series giving 8, then put the two individual series in parallel, should give 8.. Here's an attempt at a diagram, not sure how it will come out in text (< is one 4-ohm speaker, ignore the ...., which I used to take the place of spaces, yahoo seems to be compressing spaces out):

...+<-<-+
---|.........|----
...+<-<-+

Good question.

(the next day)

Well, I thought it over some more and I hope you didn't follow my advice and hook them up as shown above, cause I made a mistake. The way I'm showing it up there it would be 1/(1/8 + 1/8) = 1/(2/8) = 8/2 = 4. So that won't do it either.

The problem with your resistor idea is if you have much power going through a) you'll need a whopping big expensive resistor to handle all the power and b) all the resistor will do is dissipate power without producing sound. If you bought another 4 ohm speaker and put it in series with the 4 configured as I've described above, you would then have 8 ohms.

Answer 3

like the others said, run your negative to the negative of one speaker, then a wire from the positive of that speaker to the negative of the next, and then connect the second speaker's positive to the source positive, that will get you two speakers running at 8 ohms since they're all 4 ohms, but to wire all four from one channel is a little more complicated, if you have two channels do what was described above for each channel, otherwise I don't know exactly how to do it

Answer 4

wire them in series