Is there any way to tell the ohms of a speaker?

I'm replacing speakers in some of my cabs, and I want to make sure I match up the ohms correctly, but there were quite a few machines where the speaker had no labelling whatsoever on the back of the magnet.

For instance, my Mortal Kombat machine. It has one big speaker with a cap in it, and one smaller tweeter attached to it. Now I don't want to do damage to the game board (obviously), so I'm trying to find out what the ohms of the speakers are. How can you find out?

Thanks in advance!
Shmenge

Just use a multimeter with one lead on + and one lead on - and it will read the reistance (ohms) of the speaker.

For older speakers I always noticed its printed on the bottom of the magnet.

That's usually where it is, but for some reason most of the machines I own have jack on the magnets. The MK one I'm replacing now has all sorts of numbers and letters, but nothing that resembles the ohms.

OK I just tested the speaker, I set my digital multimeter to KΩ, and it came up 3.5. Now does this mean it's a 4ohm speaker? Or does it mean it's a 2ohm? These damn things confuse the hell out of me.

This particular one is even more of a pain in the ass, because it has a capacitor and a tweeter attached to it. Now the speaker I bought to replace it is a 4ohm, so if the original speaker is infact a 4ohm, then all of the other nonsense wont matter.

You have 4 ohm speakers- thats just fine.

Speakers rarely give a number exactly equal to their rating. I have checked many speakers in my days and they almost always vary a little from an exact 4ohm, 8ohm etc rating. The capasitor is there as a filter to help cut out the low end from reaching the tweater...nothing super fancy but it works...I have had to do this with car speakers before to stop rattle/distortion in some of the smaller door speakers.

Woo! That's great news. So when I check the other speakers, is it safe to assume the readings will always come out a little bit less than what they actually are? So say I get a 5.6 rating, that would be a 6ohm, and a 7.5 reading would be an 8? It would never be over, right?

Actually DC resistance isn't necessarily the best way to say 100 % what it is. It's close enough to be right though.

The reason I say that is that impedance will change depending on the frequency of signal you are feeding the speaker. That's why the speakers say "nominal impedance"

RJ