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quick question about qsc power amps

Discussion in 'Amps and Cabs [BG]' started by Mr. Pickle, May 8, 2006.


  1. Mr. Pickle

    Mr. Pickle

    Aug 20, 2005
    i download the pdf manual and i'm a little confuzed. when running bridged mono mode (rmx series) i seem to be under the impression that if you use the binding posts, you hook up channel 1 and channel 2 to the cab and if u use the speakon output, you only use the channel one output. is this correct?

    basically, i know the bridged mono only uses the channel one input but does it also just send all the power to the channel 1 output, or does it send it to both outputs? i preferably use speakon.

    k,
    me
     
  2. Thunder Lizard

    Thunder Lizard

    Dec 7, 2005
    Lethbridge, AB
    Canadian Distributor, Basson Sound Equipment
    If you bridge a current model of QSC amp, you use the #1 input, the #1 volume control goes up, the #2 volume stays down, and you connect EITHER to the 2 RED binding posts, OR to the #1 Speakon output. If you have the switch on the back set to "Bridge", it sends all that wattage out the #1 output.
     
  3. Mr. Pickle

    Mr. Pickle

    Aug 20, 2005
    ok thanks, the only part that confused me was the volume one control goes up, etc... do u just mean only the 1st gain knob will have an affect?
     
  4. BassikLee

    BassikLee Commercial User

    Feb 13, 2004
    Deltona, FL
    Owner: Brevard Sound Systems
    With the QSC amps, if you use the speakon out when bridging, keep in mind that you need a specially wired cable. The speakon for channel 1 actually has Ch 1's output on pins 1+/-, and channel two's output on pins 2 +/-. SO, for using the amp bridged, you want a cable that uses pins 1+ for hot, and 2+ for cold. If you use a regular cable, all you are getting power wise is channel 1's normal output.
     
  5. Mr. Pickle

    Mr. Pickle

    Aug 20, 2005
    so will just any speakon cable work?


    that's another thing. i'm going (speakon 1/4" adapter ===> 1/4" cable ===> speakon 1/4" cable adapter) does this mean i'm only getting channel one b/c it goes into a 1/4" cable and then back into a speakon?
     
  6. Sneaky Pete sent me this and it helped:
    Hang on there before you go. Speakons come in three flavors: 8 pole, 4 pole, and 2 pole. The number of conductors doesn't matter but the connector does. Most common are the 4 pole with only 2 leads attatched: 1+ and 1-.

    How do you tell? If the connector has a grey ring that you pull back and twist to remove the connection that is a 2 pole (NL2FC). If there is a thumb tab that's pulled back to remove the plug then it's a 4 pole. (there are some older versions that you twist a blue ring then pull the plug that way called "twist locks", they have been phased out)

    OK, hopefully you've found you have a 4 pole connector (look for the NL4FC or NL4FCX written somewhere on the end). Open it up and you'll see two wires leading into end, black and white. I wish I had a pic of one to post but bear with me, the set screws they are attached to both face the same direction. Orient them so they face up, away from you. Unscrew the one on the left (1-) and place it into the one directly below the remaining wire (marked 2+). Tighten the screw to make sure the wires don't come loose then reassemble the connector.

    I hope that helps, speakons are a superior way to connect amps to speakers. I hope one day 1/4 connects will be gone but 1/4's are so cheap to manufacture. Oh well...

    I followed his directions and I was set. I have a PLX2402 and run it with an Avalon U5.
    Good Luck
     
  7. Mr. Pickle-Unfortunatley if you go to a Guitar center or just about anywhere, they won't know SH%T about pins/speakon cable/-1/+2, be sure to follow the directions on configuring your speakon cable correctly. The instructions I posted worked great. If you do buy a Speakon cable from a music store, it is the right cable, you just have to do a little re wiring, no soldering, you'll just have to use a little screwdriver and swap connections.
    Good Luck!!!
     
  8. Bob Lee (QSC)

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

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    Mr. Pickle, is there a particular model that you're talking about?
     
  9. Mr. Pickle

    Mr. Pickle

    Aug 20, 2005
    well, no. i dont have the case anymore. all i know is they're Hosa (speakon =--> 1/4" female) adpaters with a 1/4" cable connecting them
     
  10. Mr. Pickle

    Mr. Pickle

    Aug 20, 2005
    that's basically what they are, but they're only a few months old.


    so, what exactly will this do? am i losing some wattage the current way i'm running it and this will help increase it?
     
  11. Bob Lee (QSC)

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

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    It actually puts out the power on both channel outputs. The upper Speakon output has both channels on it--channel 1 on 1+ and 1-, and channel 2 on 2+ and 2-. Pins 1+ and 2+ are equivalent to the red binding posts, and 1- and 2- are equivalent to the black ones.

    The lower Speakon just has channel 2 on 1+ and 1-.
     
  12. Mr. Pickle

    Mr. Pickle

    Aug 20, 2005
    so bob, are u saying that it will put all the power to channel one if u have a speakon with the right pins, OR it will distribute it between channel one and two?

    i'm getting confused by some of the technical talk. basically, i'm really just after one thing. how can i optimize my qsc to get the MOST amount of power available. i'm using a 4 ohm 4x10 avatar kappa pro that has one speakon connector on the back and two 1/4" inputs. i dont have a full speakon cable, but i could probably buy one. right now i have two (speakon =---> 1/4" female) adapters.

    thanks
     
  13. Bob Lee (QSC)

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

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    It will put out the power on channels 1 and 2. If you use a Speakon plug, it has to be a 4-pole one (NL4FC, for example), and your cable has to be wired to 1+ (channel 1's output) and 2+ (channel 2's output), and you would plug it into the upper Speakon output.
     
  14. Mr. Pickle

    Mr. Pickle

    Aug 20, 2005
    ok, thanks. i just went over to my drummers house and found out that the adapters i have are NL2FCs (2 pole then, correct?) is there anyway i can mod it or anything, or do i just need to get a new one?

    if i need to get a new one, do i have to get two adapters or can the adapter that plugs into my cab still be 2 pole?
     
  15. Bob Lee (QSC)

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

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    You need a 4-pole Speakon for the amp end of the cable. The speaker cabinet can probably take a 2-pole one.
     
  16. Thunder Lizard

    Thunder Lizard

    Dec 7, 2005
    Lethbridge, AB
    Canadian Distributor, Basson Sound Equipment
    Thanks, Bob....... I was reading the manual on pdf, and it's a bit hard to suss out .... I ended up second guessing myself. I got the impression that it was going to switch the output too. Glad you're here to save us from Me!
     
  17. Mr. Pickle

    Mr. Pickle

    Aug 20, 2005
    alright thanks, i finally understand it. i still have one more question though, just to try and further my knowledge. will the speakon (that plugs into the amp) mix the sperate channels into one power source (refering to it while it runs through the cable)? like, will the 4 pin speakon mix it down to one line of power so a 2 pin speakon could still distribute all of the power that was originally sent through the cable?


    was i basically losing have the 'power' by only using a two pin speakon?
     
  18. Bob Lee (QSC)

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

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    There's no mixing. It's just two channels acting in completely opposite, mirror-image ways so while one's pushing, the other's pulling, and vice-versa.

    On a single channel output, normally one side is ground and the other side is hot--that is, producing a voltage. In bridged mono, the speaker cable is connected to the two hot outputs, which are putting out the exact same signal voltage, except the polarity is opposite on one channel. For example, if at a given instant channel 1's output is +6.3 volts, channel 2's will be -6.3 volts; if channel 1 is -15.8 volts, channel 2 will be +15.8 volts. This way, you get twice as much output voltage as you would get from a single channel.
     
  19. Mr. Pickle

    Mr. Pickle

    Aug 20, 2005
    alright, so until i get a new speakon cable and/or adapter, would running it in parallel get me more juice than what i'm currently doing? like if i use my adapters and run channel 1 output into one of the 1/4" inputs on my cab and then run channel 2 into the other, would i be getting the same effect as bridged or am doing a big no-no or something?
     
  20. Bob Lee (QSC)

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

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    You don't need a new cable or adapter--just a new NL4FC plug to put on the cable.

    Sure, if you have two cabinets you can put one on each channel, too. What impedance are they?
     

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