What would be the impedance of 3 - 8 ohm speakers?

DrumsAndBass · #1 10-13-2011, 09:23 AM

I'd like to connect 3 - 1x15" cabinets. None of them will have a tweeter or midrange. They'll get a full range signal. What would be the total impedance ?

Thank You

Bass_Pounder · #2 10-13-2011, 09:26 AM

2.67 ohms when connected in parallel

JTE · #3 10-13-2011, 09:27 AM

Simple math. Impedance of identical loads in parallel is the individual impedance divided by the number of loads. Three 8Ω loads means 3/8 = 2.66.

If the amp is rated to work at 2Ω, you're OK. Many amps are rated with a 4Ω minimum so that's not a good idea for them.

John

tom-g · #4 10-13-2011, 09:29 AM

2.67, 12, or 24 ohms.

Cristo · #5 10-13-2011, 01:16 PM

depends on how they are connected - series, parallel, or combination

Alex1984 · #6 10-13-2011, 01:25 PM

Quote:

Originally Posted by tom-g

2.67, 12, or 24 ohms.

Also 5.33.

tom-g · #7 10-13-2011, 02:03 PM

Quote:

Originally Posted by Alex1984

Also 5.33.

Oops, missed one

313 · #8 10-13-2011, 02:14 PM

Quote:

Originally Posted by tom-g

2.67, 12, or 24 ohms.

How do you connect 3 8-ohm cabs to get 12 ohms total?

Jim Nazium · #9 10-13-2011, 02:17 PM

Quote:

Originally Posted by 313

How do you connect 3 8-ohm cabs to get 12 ohms total?

2 cabs in parallel = 4 ohms
wire the parallel pair in series with the other cab = 12 ohms

(not that you'd really want to do this, but you could)

Sneakypete · #10 10-13-2011, 02:31 PM

All above is correct but remember these are only nominal figures - the actual impedance varies with frequency. Three 8 ohm cabs paralleled up will be fine on condition your head is 2 ohms stable. That's the really important thing you need to check.