how to tell ohms on speakers without labels! need labels for order!

Discussion in 'Amps and Cabs [BG]' started by basstark, Sep 16, 2004.

  1. basstark


    Jun 6, 2004
    hey there talkbassers! check this out. i basically already posted this earlier but didnt get much response possibly because of a misleading title. i've got two speakers that are labeled (peavey black widows) but they have no impedance rating on them and no model number. 15" widows are made in both 4 and 8 ohms, but i cant play on my new cab till i figure this out. thanks yall despite my gratuity.---steve
  2. Lyle Caldwell

    Lyle Caldwell

    Sep 7, 2004
    Beg/borrow/buy a voltometer. Set it to read DC resistance (ohms). Put the red lead on one speaker terminal (+) and the black lead on the other speaker terminal (-). The meter will tell you what the impedence of the speaker is, though it won't say exactly 8 or 4. But it will be a number close to those.

    This will work if the speakers have been removed from the cab and aren't wired together. If that's not the case, let us know and we'll tell you how to check cabs.
  3. basstark


    Jun 6, 2004
    thanks for the reply. indeed. the speakers are wired together and loaded in the cabinet....
  4. Eric Moesle

    Eric Moesle Supporting Member

    Sep 21, 2001
    Columbus OH
    Can get a meter at Radio Shack for about $12 to handle this. If they're wired in the cab, remove the wires, do the test, then clip the wires back on. If they're soldered on, then you have to decide . . .
  5. Lyle Caldwell

    Lyle Caldwell

    Sep 7, 2004
    Ok, either take off the jack plate or the back of the cab (depending on the design) so you can access the tabs on the input jack where the speaker wires are soldered.

    Use the meter to read the resistance across the + and - tabs of the jack.

    You'll get one of the following measurements:

    2 Ohms : each speaker is 4 ohms and the cab is wired in parallel

    4 Ohms : each speaker is 8 ohms and the cab is wired in parallel

    8 ohms : each speaker is 4 ohms and the cab is wired in series

    16 ohms : each speaker is 8 ohms and the cab is wired in series.

    Hope this helps.
  6. basstark


    Jun 6, 2004
    thanks, and the meter i need is a voltometer?
  7. Lyle Caldwell

    Lyle Caldwell

    Sep 7, 2004
    Yup. Also known as a multi-meter. You can get them at most hardware stores or any Radio Shack. Google for more info. It doesn't have to be very fancy, just make sure it can read DC resistance.
  8. Sorry, didn't realize you didn't have a model number. Like everybody said, buy a meter. They can go by several names: multimeter, VOM (volt-ohmeter), ohmeter...You don't need to spend more than 20 or 30 bucks. I wouldn't really recommend one under ten bucks...

    An 8 ohm speaker will read around 6 to 8 ohms, usually....4 ohms around 3....

    If the speaker's blown it won't read anything (infinite resistance). Hint: the meter can also be used to check cables. Tip to tip, for example, should read 0 ohms. Tip to sleeve should read infinite. Sleeve to sleeve should be 0 ohms.
  9. basstark


    Jun 6, 2004
    why the speakers dont have model numbers is beyond me. they do have serial numbers. maybe i could try emailing peavey before i hit the sack. but it sounds like a meter isnt a bad buy anyway.
  10. IvanMike

    IvanMike Player Characters fear me... Staff Member Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    i thought pv 15" widows were all 4 ohms, at least thats what they told me a long time ago - but anyhow, get the meter, you can go around measuring all kinds of stuff
  11. srxplayer


    May 19, 2004
    Highland, CA
    Very good information.
  12. basstark


    Jun 6, 2004
    i've been looking around at widows on other sights and seen that people sell the 15's at 8 and 4.
  13. Paul A

    Paul A

    Dec 13, 1999
    Hertfordshire U.K!

    It WON'T be close! It'll be around two thirds of the actual impedance.
    So 2 ohms = 1.3
    4 ohms = 2.7
    8 ohms = 5.3
    16 ohms = 10.7
  14. Lyle Caldwell

    Lyle Caldwell

    Sep 7, 2004
    Well, it won't always be those specific numbers, but you're right, I should have said "round up to 2, 4, 8, 16" or something (hey, it was late- do I get points for spelling?). Thanks for the clarification.
  15. basstark


    Jun 6, 2004
    cool. i come back today and i have even more to go off of. thanks for the help. and if you like details, i was too tired to contact peavey last night but i found one of my bandmates father's has a voltometer. ahhh. where would the world be without engineers?
  16. Petebass


    Dec 22, 2002
    QLD Australia
    This is turning into a bit of a miltimeter apreciation thread :)

    Mine does all the usual stuff, and also has a frequency counter. So when I hook it up to my foldback speakers, it TELLS me which frequencies are causing the feedback. How cool is that?

    Every musician should own one of these, even a basic one. As Ivan says, there's always something to measure...........