1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  
     
    TalkBass.com has been uniting the low end since 1998.  Join us! :)

Anyone rewired a GK mbe cab for bi-amp?

Discussion in 'Amps and Cabs [BG]' started by gregoire1, Jan 27, 2012.


  1. gregoire1

    gregoire1

    Oct 19, 2008
    Nashville
    Anyone ever tried this? They're just so much more affordable than the neo's, and that appears to be the biggest difference.
     
  2. will33

    will33

    May 22, 2006
    austin,tx
    I seriously doubt that's the biggest difference but yeah, I suppose you could take the filter out and wire it yo 2+ and 2- of a speakon. Or use a switching jack to do it and leave the filter in there for use with other amps.
     
  3. Biggest Differences:

    Neo: 51 Lbs; MBE: 34 Lbs

    Neo: $549; MBE: $399

    Neo: 24" W x 24"H x 16"D 11 ply poplar plywood 9216 cu in.
    MBE: 19-1/2"W x 26-3/4"H x 14-3/4"D...no mention of poplar 7694 cu in.

    Neo: GK’s Paragon cast-frame Neodymium loudspeakers
    MBE: Two 12” neodymium speakers
     
  4. ACalbass

    ACalbass

    Dec 16, 2011
    All depends on what speakers are in those.
    Some of the configurations use 16 and 32 ohms speakers,so to make 8 ohms they wired in parallel.
    Of you try to rewire those,you end up with some weird impedance.
    For example,a 410 that uses 32 ohms speakers in parallel to make 8 ohms,when you divide the configuration,you will end up with two different scenarios than original : one section of 3 speakers together will give you 10 ohms,while the single speaker left will give you 32 ohms,or....
    2 speakers each section of 16 ohms each.

    And things will also change in 212.

    The idea of biamp'ing this cabs will result in less power delivered by the amp because the loads are higher.

    You check,it doesn't apply to all the cabs.
     
  5. will33

    will33

    May 22, 2006
    austin,tx

    I think he's talking about the little tweeter amp thing, in which case, the woofer wiring would be left as is.
     
  6. gregoire1

    gregoire1

    Oct 19, 2008
    Nashville
    That's what I meant, bi-ampedlike a typical neo cab with a rb series amp. (I thought the drivers were the same) highs to the tweeter lows to the woofers.
     
  7. ACalbass

    ACalbass

    Dec 16, 2011
    Ok,then you just can insert a cap between the low and highs.
    This mean you need to use a capacitor estimated value of 10 uf/600 volts from the positive of the woofers and the positive of the tweeter.
    This capacitor will act as a primitive filter for the lows and will allow highs to go to the tweeter without altering the impedance of the cabinet.
    Of course,values can be calculated better for the specific case.
     
  8. will33

    will33

    May 22, 2006
    austin,tx
    A 10uf cap would put you 1st order around 2k and fry the tweeter.

    In the OP's case, he would install a switch to move the filter that's already in the cab in and out of the circuit. Switch it in the circuit to use with regular fullrange mono amplification, switch it out and over to the 2+ and 2- speakon connections for use with the GK tweeter amp thingamajig.
     
  9. I thinkt he Neo's have Compression drivers(and horns) where the MBE have piezos, IIRC, which is why they aren't bi-amp capable.
     
  10. will33

    will33

    May 22, 2006
    austin,tx
    Aha....

    You could then put an 8ohm resistor in front of the piezo so the tweeter amp "thinks" it's a resistive load. You put 4ohm resistors on them all the time when running them without a crossover so they don't mess with amplifiers at ultrasonic frequencies but I believe the GK tweeter amp is an 8 ohm amp so you'd use an 8ohm resistor. That 50 watt amp is enough to send a piezo to kingdom come so roll it's volume up carefully.
     

Share This Page