GK - 700RB-II & NEO 212 Set Up

Discussion in 'Amps and Cabs [BG]' started by Deep Release, Sep 26, 2018.

  1. Hey Everybody! I've always had a 700RB-II, but recently purchased a NEO212. I got the speakon cable to utilize the bi-amp functionality.

    My question is this: Do I need to use both the speakon AND the 1/4"?

    I assumed I'd just need the speakon, but there was no sound until I plugged in the 1/4" with it.

    Any light you can shed would be greatly appreciated!

    Bonus: I'll also take any tips/suggestions for the EQ/bi-amp setup!
  2. voided3


    Nov 11, 2008
    The GK bi-amp system uses a regular four conductor Speakon cable wired +1/-1 for the woofer amp, +2/-2 for the tweeter amp. You do not utilize a 1/4" cable simultaneously.

    Make sure the switch on the cab is set to "bi-amp" instead of "full range", as well. The bi-amp setting is only for the four conductor cable. The full range setting is for use with either a 1/4" cable or a two conductor +1/-1 Speakon cable.
    Spidey2112, Wasnex and jeff7bass like this.
  3. wave rider

    wave rider

    Jan 5, 2005
    Speakon OR quarter inch, not both.

    No sound at all or no sound from tweeter? Your Speakon cable may be bad.
    jeff7bass and Al Kraft like this.
    1. The switch on the back was set to "bi-amp"
    2. With just the speakon cable, there was no sound at all
    3. The speakon cable just came new from GK
  4. Based on sound from the cab with 1/4 cable, it's either the speakon output of the 700RB or the speakon cable. Can you get another speakon cable to test?
    On a happier note, great looking bass!
    BrentSimons likes this.
  5. Thanks! Great sounding too! :thumbsup:

    Since the cable is brand new, I'll have my local electronics guy test out the head.
  6. Al Kraft

    Al Kraft Supporting Member

    May 2, 2016
    Northern Virginia
    Test the cable fist! It's cheap and easy to do and bad cables/connectors are not unheard of...even new.
    It may be the 50W HF amp in the head, but always check the simple things first, and never assume new parts are fine. Good luck!
    BrentSimons and eriky4003 like this.
  7. mouthmw


    Jul 19, 2009
    Yeah sounds like a bad speakon cable. Did you try both speakon outputs on your amp? NEVER use two outputs on one cab!

    BTW you can use a regular speakon cable too, that would only render the bi-amp feature useless. If you use a regular two conductor speakon:
    - when you set the cab switch to "full range" - you control the tweeter volume on the cab.
    - when you set the switch to "bi-amp" - the tweeter is basically off because the tweeter amp on your 700RB II sends no signal to the cab
    BrentSimons and Al Kraft like this.
  8. mouthmw


    Jul 19, 2009
    If the 50W HF amp doesn't work, wouldn't the main poweramp still work and only the tweeter wouldn't work?
    BrentSimons and Al Kraft like this.
  9. Al Kraft

    Al Kraft Supporting Member

    May 2, 2016
    Northern Virginia
    My bad, I thought it was just the horn that didn't work...poor reading of the posts on my part. You are 100% correct.
    mouthmw likes this.
  10. Actually, this problem is a total drag. OPs's got to order a bi-amp featured speakon cable (unless you have a friend who has one!) to find out if it's the cable or the (likely more expensive to repair) amp. As mouthmw suggested get a two conductor speakon as a plan b until you can get the four conductor speakon. Full range is better than no tweet at all.
    ExaltBass likes this.
  11. I reached out to my "guy". Although he doesn't have another speakon to test, he does have a way to test the cable itself.

    I appreciate everyone's feedback. I need to do more posting and less lurking on here!
    BrentSimons, gregmon79 and wave rider like this.
  12. mmbongo

    mmbongo I have too many basses. Supporting Member

    Very unlikely that it's a problem with the amp (but not impossible!) since the 1/4 output works, which is is parallel with the Speakon output. I say bad cable or something weird with the cabinet. Just try a normal Speakon cable.
  13. tadawson


    Aug 24, 2005
    Lewisville, TX
    OK, let's try this . . .the Speakon 1+/1- are the same signal lines as the 1//4" jack . . . 2+/2- are the tweeter. So some tests:

    1) 1/4" only, cab set to full range (You have said this works)
    2) Speakon only, cab *stilll* set to full range. (This is electrically identical to #1, should sound the same)
    3) If #2 works, leave the cable alone, and flip the cabinet to biamp. (This switches out the crossover in the cab).

    If #2 fails, then it's the wiring to the Speakon jacks in the amp or cab, or the cable.
    If #2 works, and #3 fails, the issue is the full range/biamp switch in the cab.

    Were both of these new to you? The chance of the connections to both the 1/4" and Speakon being bad in the amp is minimal, since those are likely on a PCB (and tested pre-ship . . .literally, the only thing between the Speakons and the 1/4" are copper conductors). In the cab, it is likely loose wiring, and unless some jughead tore up the input plate, is also, not likely, but easy to check by taking the plate off the back of the cab. The switch may not be as obvious, and I don't know if it is on the crossover PCB or loose . . . There is also the possibility that whoever built he Speakon cable got one end rotated by a pin . . .
    Deep Release and 5StringPocket like this.
  14. somebrains


    Feb 7, 2017
    You can make a 4-conductor speakon cable easily.
    Prime will get you wire and Neutrik ends.
  15. tadawson


    Aug 24, 2005
    Lewisville, TX
    Hell, 14/4 cable ideal for Speakon cables is a Home Depot (or electrical supply house) item . . . . no sense in ordering copper . . . Speakons can be had in the US from Mouser electronics (www.mouser.com) at a very good price, and same day ship, if not from your local music store, pro audio dealer, or electronic parts supplier.
    Last edited: Sep 26, 2018
  16. Wasnex


    Dec 25, 2011
    Be advised that some knock-off speakon plugs do not work reliably with the real Neutrik jacks.
    bumperbass and wave rider like this.
  17. Jack


    Sep 6, 2003
    Northumberland, UK
    This may be patronising but it caught me out on day 1 owning a GK. After you insert the speakon you have to turn it 90 degrees.
  18. Spidey2112


    Aug 3, 2016
    BrentSimons likes this.