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Attention QSC PLX Owners: Setup Questions

Discussion in 'Amps and Cabs [BG]' started by doc540, Apr 27, 2004.


  1. doc540

    doc540

    Jul 28, 2003
    Beaumont, Texas
    Just bought a used PLX1602 and need suggestions with setting it up.

    Preamp: Sansamp Tech21 RB1
    Speakers: Avatar B210 (4ohm) and B115H(4ohm)

    If I want to run both speakers at the same time (from a mono signal from the Tech21), how should I set the dip switches on the 1602?

    It appears that "Parallel Input" is the way to go, but I'd like to hear from players who are already using a 1602 with two cabs.

    And what about the clip limiters and input filters? How should those be set for running bass cabs?

    Thanks!
     
  2. lo-freq

    lo-freq aka UFO

    Jan 19, 2003
    The Republic of Texas
    Switches are listed by numbers.
    Clip Limiter is recommended.
    Filter is your choice (I don't use mine--if you do want to use a filter, I suggest using 30Hz).


    #__Switch position______Operation
    1. Left________________CLIP LIMITER ON
    2. Your Choice_________LF FILTER ON/LF FILTER OFF
    3. Right_______________LF 30 HZ
    4. Right_______________PARALLEL
    5. Right_______________PARALLEL
    6. Right_______________PARALLEL
    7. Left________________BRIDGE MODE OFF
    8. Right_______________LF 30 HZ
    9. Your Choice_________LF FILTER ON/LF FILTER OFF
    10. Left_______________CLIP LIMITER ON
     
  3. doc540

    doc540

    Jul 28, 2003
    Beaumont, Texas
    Well, that was easy enough.

    Thanks, bro.
     
  4. atldeadhead

    atldeadhead

    Jun 17, 2002
    Georgia
    I just picked up a PLX 1202 and an RBI myself.

    I'm running bridged mono (1200 watts @ 4 ohms) into (2) Aguilar GS112's. I don't know about you but I'm absolutely lovin' that "tubey" goodness and little bit 'o grind. I'm using the same settings as lo-freq described but thus far I have been using the 30hz filter. Oh yeah, I'm playing a Modulus Q5 through the rig.
     
  5. doc540

    doc540

    Jul 28, 2003
    Beaumont, Texas
    If I ever did want to run it bridged mono, with two 4 ohm cabs, how would I connect the speakers to the back of the power amp? I'm using banana plugs, and, as usual, I'm confused by the owner's manual referring to "combining the power of both channels into "one" speaker.

    Later it says under "WHEN TO USE (OR NOT)":
    Use bridged mono to deliver the power of both channels to a single 8- oor 4-ohm load.

    With two four ohm cabs, how would they connect?

    Thanks again.

    btw: When I wire it all up and crank it, I'll give you a report.
     
  6. monkfill

    monkfill

    Jan 1, 2003
    Kansas City

    Two 4-ohm cabs would give you a 2-ohm load. I think the limit on a PLX (and most power amps) is 4-ohms in bridged mode. You can run one cab on each side of the amp in stereo mode, and I believe you can run a 2-ohm load on each side in stereo mode, just not bridged mono.
     
  7. doc540

    doc540

    Jul 28, 2003
    Beaumont, Texas
    Yeah, that's what I thought. No can do with two 4-ohm cabs.

    No problem, it makes plenty of power in the Parallel Input mode.

    Thanks again!
     
  8. lo-freq

    lo-freq aka UFO

    Jan 19, 2003
    The Republic of Texas
    FYI: You can't bridge into two 4ohm cabs, but you could run them both off one side in parallel mode (800W total). Not much point since you get more watts per cab with one 4ohm cab per channel running in parallel (500W + 500W = 1000W).

    Of course, you can bridge into two 8ohm cabs (or one 4ohm cab) and get the full 1600W.
     
  9. rojo412

    rojo412 MARK IT ZERO! Supporting Member

    Feb 26, 2000
    Cleveland, OH.
    I hate to re-open a SUPER old thread, but I have a similar question and would like to know what the consensus is.

    I'm running my 1602 into 1-8 ohm Goliath III 4x10 cab. If I am bridging the amp and want to run the filter (30), I should have all the switches on the right side, correct? The "On" side, if you will?

    Also, I should just be using the Ch. 1 volume knob, correct?
     
  10. orskard

    orskard

    Mar 17, 2004
    Indiana
    hey, i also have a PLX 1202 and im gunna run mine with a avatar 2x10 untill i get a 15 and im getting an RBI soon. Seems like a popular rig. I hope its loud enough.
     
  11. 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
    If you want to bridge the amp, then set switch 7 to "bridge mode on" and switches 1 through 3 the way you want.

    Yes, you use only channel 1's gain control.
     
  12. 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
    The factory owner's manual says nothing about how many speakers the amp can drive in bridged, only that they constitute one single load of 4 ohms or higher, as in mono.
     
  13. rojo412

    rojo412 MARK IT ZERO! Supporting Member

    Feb 26, 2000
    Cleveland, OH.
    Thanks, Bob!