Speaker Ohm rating

[WezV]

Think i will ask a techie question for once.

I have just orderd a matamp little rock so needed to find a speaker cab.

It will actually be the first time i have owned a head and speaker style amp because i am usually a combo guy and even when i built my own amp i went with one speaker that had the right ohm rating.

ANyway i have just been given the top half of a 70's carlsboro 4 x12" cab - yes, actually sawn in half but it was free and once recovered to match my matamp  should look fine.

The speakers are Mckensie's (sp??) and each one measures 6.5 Ohms. I was expecting them to be 8 ohms

So if i wire them in series i will get 13 ohms and if i wire them parallel i will get 3.25 ohms

The matamp has 8 and 16 ohm outputs.

My Home made amp is 4 ohms

OK, questions.

is it normal to get 6.5 ohm guitar speakers or is something weird going on?

Would it be best to wire them in series (13 ohm) and use the 16 ohm output on my amp or is that too much of a difference?

Should i just bite the bullet and buy some new bloody speakers?   actually i probably will soon anyway

I am actually thinking of putting a series/one speaker/parallel switch onto the back of the cab so i can use it with my home made amp and the matamp

[Twinfan]

Wire it in series and use the 16ohm output - it will be absolutely fine. 8ohm speakers are never exactly 8ohms anyway  ;)

Check out the DC resistance specs of the Celestion G12H here on their site:

http://professional.celestion.com/guitar/products/classic/spec.asp?ID=7

[WezV]

ah, i think i have it sorted - i was measuring resistance rather than impedance - which makes a lot more sense now really.  

SO i do have 8 ohm speakers and can wire the 2 x 12 cab for 4, 8 and 16 ohm operation like i wanted

Cheers again twinfan

[Twinfan]

Nay problem Wez  :D