amp clipping/need advice please.

Discussion in 'Amps and Cabs [BG]' started by buckethdd, Jul 4, 2003.

  1. buckethdd


    Jan 15, 2002
    SF, CA
    ok...i have a setup that is seemingly fairly common on this forum. i have done some searches and gotten some good info which i have used. i am now somewhat at a loss and feel the need to post my specific issue. please bear with me.

    QSC rmx 2450 poweramp / ampeg svp pro preamp / eden 410 xlt (700w)...clean no effects. i am using a warwick thumb with bartolini pickups and running it in passive mode exclusively. the eden is new, having replaced my old combination of boogie 15 and epifani 12. qsc came back from the factory with a clean bill of health. i have used 3 other preamps thinking there may be something wrong the pre. i have run the qsc in parrallel and in bridged mono. i have changed speaker cables.

    what continues to happen throughout all of these different scenarios is clipping at moderated volumes. it gets somewhat loud but nowhere near what it seems like it should. does anyone have any advice that i might try that i haven't already? do i need more power? that seems unlikely. any advice and/or tips are generously appreciated. thank you very much.
  2. lo-freq

    lo-freq aka UFO

    Jan 19, 2003
    The Republic of Texas
    When you bridged your amp, what kind of connection did you use at the amp (did you follow the owner's manual instructions regarding connections for bridged mode?)?
  3. buckethdd


    Jan 15, 2002
    SF, CA
    i'm not sure what you mean. can you be more specific about what kind of connection?
  4. When connecting in bridged mode, the connection to the speakers doesn't use the same terminals as a normal stereo connection would. On the rear of your RMX 2450, a bridged mono connection would use the two center connections of the terminal block/banana jack field. This might seem abnormal to you, because these are normally the (+) connections on both sides when using normal stereo wiring. If you are using the Speakon connectors, the Speakon cable connector has to be specially wired for bridged mode by using different connections in the 4-conductor plug.

    I tried to attach the pdf of the manual I downloaded from the QSC website, but it was too large to be accepted here.

    Also, have you tried to measure the output of your preamp, to make sure the signal isn't hotter than the input of the RMX 2450 is designed to accept?

    Bob Lee, are you around to help out?
  5. buckethdd


    Jan 15, 2002
    SF, CA
    thank you...i am using the speakon connectors, and have found the manual online and the diagram for the rewire. i will try this today and see what happens.

    no i haven't...i have seen on this forum that a few people use this setup (qsc 2450/svp pro), so i assume it is ok...
  6. buckethdd


    Jan 15, 2002
    SF, CA
    i was too ignorant to figure out how to rewire the speakon plug, so i went to gc and bought a banana to 1/4", plugged in to the bridged mono outputs, flipped the dip switches to bridged, and cranked her up...clean and clear and NO CLIPPING. haven't played with the band yet, but i was getting pretty loud alone so i'm pretty sure this was the issue. thanks very much for the help from you guys.
  7. Petebass


    Dec 22, 2002
    QLD Australia
    The problem with downsizing your rig is that you have to push it harder to get the volume you've become accustomed to. This could be contributing to the clipping as well.

  8. No problemo.

    "When the going gets weird, the weird turn pro."