Speaker Wiring Issue

[jeremy]

two 16 ohm speakers in parallel are 8 ohms
two 8 ohm speakers in series are 16 ohms

for series its just additive, for parallel its Rt= R1R2/R1+R2 so 8=16x16/16+16 so 256/32=8

 

[Lazarus1140]

Or to put it in context for this cab: each speaker is 15 ohms. Two 15 ohm loads in series is 15+15 = 30 ohms. Two 30 ohm pairs in parallel is 1/30 + 1/30 = 1/total, so that's 2/30 = 1/15. 15 ohms would be the total load in series parallel.

If that math is wrong, please let me know, because that's the way I've been adding up my speakers and I would hate to be wrong when it counts.

That is correct and concurs with the results of my calculations as stated in the opening post.

 

[AdrianSD]

What is two 16 ohm speakers in parallel?

Is it 4 or 8 ?

I have two 16 ohm at the house and I will check when I get back

But I believe my math is correct

Depends on the formula used, I guess As per Jeremy post above, 1/Rt = 1/R1 + 1/R2 + ... + 1/Rn. In this case: 1/Rt = 1/16 + 1/16 = 2/16 = 1/8 -> Rt = 8.

On the 4 vs 16 ohm dilemma: I have 3 amps, all have 4 and 8 ohm taps, but only 2 have 16. The Mesa Express doesn't but can take 16 ohm load in the 8 ohm output according to the manual.

 

[jeremy]

you can not wire two 16 ohm speakers for 4 ohms. in parallel its 8, in series its 32.

i usually like my single speaker cabs to be 8 ohm. for two speaker cabs, i usually use two 16 ohm speakers wired in parallel for 8 ohm. though i do have a 2x10 cab with two 8 ohm speakers wired to a marshall style plate with selector so i can run both in series or both in parallel, or run each as 8ohm by itself (stereo)

i dont lug 4x12s any more

as far as the mesa, yeah, its just a mismatch so you might not get quite the same tone or power, but they are build robustly enough to handle it. same with most old fender amps

 

[Artie]

I'm not positive about this, but I think the reason they came up with the (R1 x R2) / (R1 + R2) formula, was that it was easier to do with pencil and paper. The downside, of course, is that it was only good for two resistors. That made adding three or more, a bit tedious.

But now that we all have calculators built in to our phones, with the "1 / X" key, the reciprocal of the reciprocal method is actually easier, and will accommodate any number of resistances, (or impedances), in parallel.

 

[ehdwuld]

So what did your phone say the answer was?

16 in parallel with another 16 equals........ What?

 

[Seashore]

8

 

[Artie]

So what did your phone say the answer was?

16 in parallel with another 16 equals........ What?

What Seashore said. With equal value resistors, you don't really need a calculator. Parallel becomes half, series becomes double.

With unequal value resistors, the total resistance will always be smaller than the smallest resistor.

 

[ehdwuld]

Ok