Question about NU4-6000 bridge/stereo/mono..

  1. #1 by Darin Warren on 04-02-2017
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    Posts: 130

    Question about NU4-6000 bridge/stereo/mono..

    I have searched and cannot find the information I'm looking for, so I'm asking those that know.

    I have an nu4-6000 and 4 JBL PRX 12" wedges running one channel each. I feel like there should be a bit more girth and headroom from these speakers than I'm getting. I'm considering buying another NU4 and bridging 2 channels an each amp, doubling the wattage to each speaker.
    Am I thinking about this correctly? I have it set up now and am testing this. I have AUX 1 from XR18 into CH A on NU4, switch set to BRIDGED and out of A to a wedge. And I have Aux 3 n XR18 going to CH C, switch set to stereo and from CH C to a wedge. I am A/B'ing back and forth between AUX 1 and AUX 3, hoping I'd hear some difference since AUX A is running through a BRIDGED channel and AUX 3 is not. I'm hearing no difference, at all. Zero.

    My question is, do I have the amp set correctly, nothing plugged into B in or out, and should I be expecting to hear a difference at all?

    Thanks, Darin
  2. #2 by Darin Warren on 04-02-2017
    Darin Warren's Avatar
    Posts: 130
    I'm looking at the back of the amp, it looks like I need to have the speaker cable wired for the bridged signal?
  3. #3 by Aaron Duerksen on 01-11-2018
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    Posts: 217
    - Darin Warren wrote View Post
    I'm looking at the back of the amp, it looks like I need to have the speaker cable wired for the bridged signal?
    I know this is late, but I just now saw it. I'm usually not on the Instrument Amp site.

    Anyway, yes, you do need to have the speaker cable wired for the bridged signal. The bridging switch does nothing for the output connections, and so the sticker is accurate to say that the bridged signal appears on 1+ and 2+ of Ch A/C. Ch B/D appears on 2+ of Ch A/C anyway, which is useful for non-bridged bi-amp'ing, and 1-/2- are always ground.

    For my system, I made a pair of roughly 6-inch adapters from a 4-pole speakon plug, a 2-pole speakon jack, and some 14AWG speaker wire that I already had. 1+ to 1+ and 2+ to 1-.

    For what we've done with it so far, we could have used the 2-channel version instead, which is really the 4-channel's power stage permanently bridged, but I was going for flexibility in a portable, general-purpose system.