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mesa 4x10" 8 Ohm to 4 Ohm Modifikation

Discussion in 'Amps and Cabs [BG]' started by nicnoid, Dec 13, 2002.

  1. nicnoid


    Dec 13, 2002
    hi there,
    i was wondering if i could modificate my mesa cab from 8 to 4 Ohms, in order to get higher volume, because my power amp (a OSC RMX 2450) doesn´t deliver as much as i would desire with the mesa(600w@8Ohms) hooked up...
    i was already thinking about selling the cab and getting a more matching one (impedance),but since i like the mesa,i thought this could be a way...
    But if this could decrease the sound quality of the Cab, i would rather decide not to do it...
    can anyone give me a hint ?
  2. patrickj


    Aug 13, 2001
    Ellicott City, MD
    Endorsing: Spector Bass Guitars
    Get a volume pedal. Or something with a volume (not gain) - (digi fx, etc).

    The gain knobs on the PA aren't really volume knobs, even tho turning them boosts the volume a bit. They adjust the sensitivity of the amp reading the incoming signal. If you want to boost the volume, it has to start louder for the amp to make it louder, hence a volume pedal.
  3. There's no practical way. You have in there now four 8 ohm speakers wired in series/parallel to equal 8 ohms total. There's no way to wire four 8 ohm speakers to come out to 4 ohms.
  4. nicnoid


    Dec 13, 2002
    thanks mudbass...
    damn,so i guess i need a different cab...
    maybe a ampeg 8x10"....damn,choices...
  5. Nick man

    Nick man

    Apr 7, 2002
    Tampa Bay
    He could wire them all in parallel to have a 2 ohm load, but then were looking at problems with the tweeter/crossover circuit which was meant to run in an 8 ohm system.

    How about adding another 8 ohm cab to the system to make it run at 4 ohms total?

  6. Rather than get an 8x10 and since you like your present cab so much, do something along the lines that Nick Man suggested and get another Mesa 4x10 cab. The two together equals 4 ohms plus you have the versitility to take along one or both cabs as you need them.
  7. Nick man

    Nick man

    Apr 7, 2002
    Tampa Bay
    Or a 2-10 so you can take it along to practice.

  8. There ya go. :)
  9. nicnoid


    Dec 13, 2002
    i also thought about getting another 4x10" with 8 oHms, but i don´t know how to connect both to one channel of my rmx 2450 in order to get the 4 ohms ( from the combined 8 ohm loads).
    anyone experienced in wiring...?
  10. Easy.

    amp (+) ------> cab 1 (+)

    cab 1 (-) ------> cab 2 (+)

    cab 2 (-) ------> amp (-)
  11. nicnoid


    Dec 13, 2002
    sorry,allen, I don´t really get that...:confused:
    someone there to explain to a fool?
  12. Just plug your first cab into the amp as usual... then plug the second cab into either the second output on the amp or into the second jack on your first cab. That's really all there is to it.

    Good luck.
  13. Jon's right - I wasn't paying attention :(

    Just daisychain the cabs - they'll work just fine.

    Ignore the wiring diagram I stuck up there - that's a series diagram and would be a good way to get a 16 ohm load out of two 8 ohm cabs, but that's not what you asked for, was it ;)

    I don't know why I thought series when you asked about parallel wiring. Sorry for the confusion.
  14. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    As others have mentioned, you can't convert an 8 ohm 4x10 to a 4 ohm 4x10 just by rewiring.

    What kind of preamp are you using with your power amp? Is it capable of driving the power amp to full output? If not, work on that issue first.

    If you like the Mesa cabinet, it's important to understand that if you had the same cabinet with a 4 ohm impedance, it wouldn't be much louder as it takes a doubling in power to increase sound pressure by 3 db, the amount generally considered as the smallest change that an average human can notice.

    So, I go back to my original question...do you know that your preamp provides enough output to properly drive your power amp?

    Having just gone back and re-read your original post. If you rewired your cabinet to split the 10s into pairs, you could run a 4 ohm load off of each channel and run the inputs in parallel (my PLX has switches to connect the inputs in parallel but I don't know about the RMX amps). Just a thought.
  15. nicnoid


    Dec 13, 2002
    at the moment i have to use the preamp section of my swr silverado combo...
    i never thought about this thing having a poor output...
    good point there,thanks billy!
  16. pullejo


    Jun 26, 2002
    Atlanta GA
    I've got a Mesa 5410 (4 x 10" + 1 x 15") powerhouse and some of my wiring has broken loose from my rear connector panel. If I send you a picture of mine, could you possibly compare it to yours? I haven't been able to hunt down a wiring diagram anywhere and I'd like to do this right.

    Thanks a ton.

  17. Use a 'Ausgangsubertrager' from Glockenklang!! They sel these adapters/converter from 8 to 4 ohm, so you can use the full power of your amp on a 8 ohm cab.!
    www.musik-produktiv.de nr. 3048004 €115,-
  18. That sounds like the wirst idea ever. I don't know why Glock sells those things. They sound horrible and suck up both power and tone!
  19. Useless in your opinion........ok, i have no experience with that thing but i thought, Glockenklang, these guys no what they are selling!!!

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