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Power Amp Questions

Discussion in 'Amps and Cabs [BG]' started by freshmeat1989, Jun 10, 2004.


  1. Im getting probably a QSC PLX 1602 soon and came up with some questions while looking at the back panel.

    1. How do you connect two cabs to one channel? I only see one banana plug out, and 1 speakon out (for each channel). Would you have to use each of those?

    2. Can you only use 1 cab when bridging at 4 ohms? What types of cable do you have to use when bridging?

    I have more questions, but just can't think of them right now. I'll post them when I can think of them. Thanks for any replies!
     
  2. Wes Whitmore

    Wes Whitmore Supporting Member

    Mar 10, 2003
    Columbus, OH
    Someone can confirm about the PLX in particular, but bridging an amp basically makes it into one big mono amp, and only the right output works. You run that single speakon out to your cab. If you want to run multiple cabs, you daisy chain from that speaker to the next cab, and so on. This is assuming that your cab has two speaker/1/4" jacks on it. If neither do, then you will have to make a simple custom cable.
    Wes
     
  3. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    1. Any way you can. If using both the Speakon and the binding post works for you, that's a valid way of doing it. If your cabinets have jacks in parallel, you can run a cable from the amp to a cab, then another cable from there to the next cab.

    Or you can parallel the inputs of the amp and connect one cabinet to each channel output.

    2. You can use any number of cabinets when bridging the amp, as long as the net impedance is 4 ohms or higher.

    Use a speaker cable. If you use a Speakon plug on the amp end of the cable, make sure it is wired to terminals 1+ and 2+, and connect only to the upper Speakon output. If you're not sure how the cable and plug are wired, open up the Speakon plug and check; do not just continue on obliviously. If you use the binding post outputs of the amp, you would connect to the two red terminals only.

    The manual shows all of this.
     
  4. Here ya go. PLX Manual
     
  5. Thanks a lot everyone! I look forward to buying from you Bob!

    One last question. When daisy chaining, can you run a cord from the speakon of channel 1 to the speakon of a cab, then from the 1/4 of that same cab, to the speakon of the next cab?
     
  6. Wes Whitmore

    Wes Whitmore Supporting Member

    Mar 10, 2003
    Columbus, OH
  7. Wes Whitmore

    Wes Whitmore Supporting Member

    Mar 10, 2003
    Columbus, OH
    That amp wont fit in the SKB 4 U shallow rack, if you were planning on doing it. Just about the only amp that will really fit in there is the Carvin line, and they just barely fit.
    Wes
     
  8. Yep, get the full size SKB rack. Will it fit the Roto rack?
     
  9. Yeah, I gotta change it. I'm almost positive it will fit in the Gator Short 4u rack though.
     
  10. Wes Whitmore

    Wes Whitmore Supporting Member

    Mar 10, 2003
    Columbus, OH
    I think the gator is good for 12".
     
  11. BOO YA! :D