Psst... Ready to join TalkBass and start posting, make new friends, sell your gear, and more?  Register your free account in 30 seconds.

Miss Matched Ohm's

Discussion in 'Amps and Cabs [BG]' started by cassanova, Dec 2, 2000.


  1. cassanova

    cassanova

    Sep 4, 2000
    Florida
    Ok this may be a stupid question, but I dont claim to be an amp guru. I will admit that it was plain stupidity on my part for not catching this much sooner. DUH@ME

    My 4x10 cab is rated at 8 ohm, my 1x15 is rated at 4 ohm, Am I in any danger of ruining my head or speakers? I really cant believe I didnt notice this when I got it. My Head is rated at 4 & 8 ohm if that helps any.
     
  2. this WILL hurt your head somehow.. ask the techs about it.. the 8+4= 2.xxx or something around there so it messes up stff and is no good =P

    -Willz
     
  3. virtual.ray

    virtual.ray

    Oct 25, 2000
    Is she a new Adult star? O.K.,seriously this will give you 2.6 ohms when you run 'em both in series.Some amps are O.K. with that but some are most assuredly not.Check the manual or website of the amp manufacturer 1st.
     
  4. notduane

    notduane

    Nov 24, 2000
    Location
    C'mon dude :mad: The only stoopid question is the one left un-asked.
    Without too much E/E type stuff, YES you normally match
    a 4 ohm output with a 4 ohm cabinet, 8 => 8, etc.
    This will ensure that max power (no, not member Max_Power)
    will be transferred to the load, instead of being
    transmogrified into heat. Another thing to consider is
    "series" or "parallel" wiring. Fer' instance: Two 4 ohm
    speakers wired in PARALLEL will result in a 2 ohm load,
    whereas two 4 ohms in SERIES will give you an 8 ohm load.
    Here's a crude attempt at a schematic:

    SERIES
    ======
    v + [AMP SPKR OUT] - <

    > + spkr - > + spkr - >

    PARALLEL
    ========
    v + [AMP SPKR OUT] - <

    > + spkr - >
    > + spkr - >


    Then of course, the whole thing's backwards for capacitors :(
     
  5. cassanova

    cassanova

    Sep 4, 2000
    Florida
    I think I'm running them in series the back of my head has to 8 ohm speaker outputs so I use both of them instead of daisy chaining it from one cab to the next. I always get those 2 confused..lol
     
  6. notduane

    notduane

    Nov 24, 2000
    Location
    Here's a brief article on speaker hook-up:
    "What the heck is "Impedance" anyway????"
    http://www.soundav.com/link13.html
    The graphics are purty :D .

    There's a bunch of good meta search engines out there -
    http://dogpile.com , http://ask.com , http://about.com ,
    etc., that'll help you find just about anything.
    Just mind your phraseology :eek: . I entered "hooking up
    multiple speaker cabinets" and got advice on fishing tackle :( .
     
  7. danhei

    danhei

    Jan 21, 2000
    Almost all amps have output jacks in parallel. So if your amp can only handle a 4 ohm load, your 4 and 8 ohm cabs (2.67 combined) will be under the minimum. This is BAD. If you want to get the most out of your amp use ONLY the 4 ohm cab or ONLY 2 8 ohm cabs. One 8 ohm is fine but you won't get the max power.

    Dan
     
  8. danhei

    danhei

    Jan 21, 2000
    I just read in your profile that you have a Hartke head. All Hartke's I've seen run 4 ohms minimum. So DON'T run the two cabs together!

    Dan