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Changing 212 from 8 to 4ohm

Discussion in 'Amps and Cabs [BG]' started by Blues Cat, Aug 29, 2007.


  1. Blues Cat

    Blues Cat Payson Fanned Bass Strings Owner Supporting Member Commercial User

    May 28, 2005
    Katy, Tx
    Payson Fanned Bass Strings Owner
    I'm thinking about changing my Carvin BRX12 (212) cab from from 8ohm to 4ohm by changing out the 2 stock 16ohm speakers with two 8ohm speakers, resulting in a 4ohm cab.

    My question is do I have to change out the crossover too? It doesn't seem like I would but I wanted to see if anyone new for sure. The crossover has a set of wires going to each speaker separately if that matters. (2 negs and 2 pos)
     
  2. 73jbass

    73jbass Supporting Member

    Apr 17, 2004
    Ellenwood,Ga.
    No changes needed.Just replace the drivers and go for it.
     
  3. A9X

    A9X

    Dec 27, 2003
    Australia
    I'd check with Carvin. If there is a lowpass on the 12's, then it will definitely be different between a 4R and 8R load.
     
  4. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    You also have to consider that the cabinet was designed for drivers with specific parameters. What will work for the stock speakers will not heccessarily work for others that you buy. As A9X suggests check with Carvin, they may have 8 ohm versions of the drivers. All Carvin Xovers I have seen do indeed have low pass sections so this would have to be changed.

    For interest, why the swap??
     
  5. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    Probably he believes it would be louder with the 4 ohm load. Reality check: in the region of highest demand, 80 to 100 Hz, these drivers are displacement limited to 100 watts input each, so anything more won't result in higher output. The change would only be useful if the amp isn't capable of delivering at least 200 watts into 8 ohms.
     
  6. I would leave them alone, and add a second 212 cabinet. That will give you a 4-ohm load from the pair, and give you +6dB more noise at the same output voltage.
     
  7. Blues Cat

    Blues Cat Payson Fanned Bass Strings Owner Supporting Member Commercial User

    May 28, 2005
    Katy, Tx
    Payson Fanned Bass Strings Owner
    I don't believe that at all Bill. The best way to increase volume is add speaker surface.:D

    The stock speakers (2512's 16ohm) are being replaced under warranty. So if they give me an 8 ohm 2512II option I might take it. I'm not interested in buying a new crossover. If the original crossover won't work at 4ohms I'm going to insist on the original 2512's 16ohm.

    The 4ohm mod would open the door to add a BRX210 4ohm.
     
  8. Blues Cat

    Blues Cat Payson Fanned Bass Strings Owner Supporting Member Commercial User

    May 28, 2005
    Katy, Tx
    Payson Fanned Bass Strings Owner
    Just got off the phone with Carvin tech support and he says there's no low pass, so you can change the speakers out from 8ohm to 4ohm.
     
  9. jmain

    jmain Oo, Uhn't uh, Yes! Supporting Member

    Apr 23, 2005
    Alexandria, VA
    If it was me (and it ain't) I'd go this route. I wish my 310 cab was 8 ohm so I could add another cab and not go below the 4 ohm rating on my amp.

    Carry on...
     

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