Impedance Question

[donjfelix]

I want to make a 4x10 cab 4ohm, which combination do i have to use, 4 drivers 8ohm or 4ohm?

[coreyfyfe]

No, four 8 ohm speakers set up in series parallel like that will give you an 8 ohm cab. For a 4 ohm cab like that you'd want 4 ohm speakers in a series/parallel combination or four 16 ohm speakers in parallel.

Here is an easy calculator tool to use if you don't want to do out the math yourself:
Shavano Music Online - Speaker Wiring; Impedance Calculator

[Eric Moesle]

Originally Posted by Dekker

Two 8 ohm speakers in series, run in parallel with another two 8 ohm speakers in series, will give you a 4 ohm cabinet.

8 + 8
------ = 4 ohm
8 + 8

Don't forget to take power handling and the crossover into consideration.

(unless I am mistaken in what you are asking for...)

Totally incorrect info. Four 8 ohm speakers in series-parallel gets you a net of 8 ohms.

You need four 4 ohm speakers in series-parallel to get a net of 4 ohms.\

You are the "official fEarful builder for Canada" and you don't know this basic impedance question????

[B-string]

Or use 4 16 ohm speakers all in parallel.

[Stick_Player]

Some of the Big-Boy manufacturers (i.e., G-K) use four 32-ohm speakers wired in series to get an 8-ohm load. Although I see now that you want a total 4-ohm load.

Use the calculator.

Impedance Calculator

[BassmanPaul]

If all you are doing is wiring the drivers in parallel and they are identical just divide the common impedance by the number of drivers. 32Ω, 4 drivers: 32/4 = 8Ω.

[bassmeknik]

Whenever you are using four identical drivers in series parallel the total impedance is equal to the impedance of one driver. Do the math correctly (poster #2 is in error) and 4-4 ohm drivers work out to 4 ohms just as 4-8 ohm drivers work out to 8 ohms. So if wired in series parallel you need 4 ohm drivers.

If, however you wire all 4 drivers in parallel and use 16 ohm drivers you will also get a 4 ohm cabinet.

So the short answer is you need either 4 ohm drivers or 16 ohm drivers to get 4 ohms out of a 4 driver cabinet. 8 ohm drivers WILL NOT WORK.

[JTE]

Originally Posted by Stick_Player

Some of the Big-Boy manufacturers (i.e., G-K) use four 32-ohm speakers wired in series to get an 8-ohm load. Although I see now that you want a total 4-ohm load.

Use the calculator.

Impedance Calculator

No way. Four 32 ohm speakers in series is 32*4=128 ohms. Four 32 ohm speakers in PARALLEL will give an 8 ohm load however.

John

[Stick_Player]

Originally Posted by JTE

No way. Four 32 ohm speakers in series is 32*4=128 ohms. Four 32 ohm speakers in PARALLEL will give an 8 ohm load however.

John

Oops, yes, I stand corrected. That's why I use the linked Impedence Calculator, complete with a schematic.