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SRX725, srx738 and SRX728s need help...

richardtarichardta Posts: 5
I have 4 JBL SRX725 and 2 JBL SRX738 with 2 JBL SRX728. I wonder how to setup with the DR260.

Oh BTW I try to replace my QSC ampl to CROWN ampl. Any suggest what should I get for all my Speaker and Sub.

Please give me some idea Thanks.



  • DraDra Posts: 3,777
    Can you give us a lot more info about your set-up and what you are trying to do? What QSC amps (and why changing)? What Crowns are you going to?

  • Hi.
    Seriouly, I dont know what to do with those yet. I get it from my old friend, who need money to buy a new house.

    I have 6 QSC RMX2450 and 2 QSC RMX1450 in the rack.
  • GadgetGadget Posts: 4,915
    Well, you still haven't given us the intended purpose of said system (you know... what your going to use it for...live sound...DJ...Karaoke...) or how big a venue... like, are delay towers warranted...? Not sure you even know what those are...But hey, with a number of odd tops with different patterns it's not clear just how you envision using those together... You see, overlapping coverage patterns make for coverage problems that will manifest themselves in comb filtering, cancellations, nulls and modes...and all sorts of fun sound skewing things...

    I guess what I'm saying is mixing coverage patterns is a really bad idea, and allowing coverage patterns to overlap....an even WORSE scenario is multiple sources with different LF coverages and frequency responses... I guess I mostly wonder what the SRX 738's are doing in this system...Those are mainly used where subwoofers are not being deployed... but obviously you have subs here..your kinda shy on power and subs here also...

    I guess I'd say utilize the 725's bi-amped and the 728's and leave the 738's out unless "other coverage" is necessary... with the sub/amp situation I'd try and always stack the subs together, and find another way to get the 725's up if necessary, you cant sit 2 725's on one 728 on end anyway and one sub high, the 725's aren't normally going to be high enough to get over a crowd...(maybe use the 738's as speaker stands :shock: :shock: )

    The tunings for a SRX725/728 triamp system is available from JBL professional in their "Tunings"
    http://www.jblpro.com/catalog/general/t ... D=18&Run=1
    In fact, that setup is available in .dwp form for direct download into the 260...or manually in pdf form you can input yourself... though for a novice I recommend the former...
    Use the SRX725BSUB.dwp file, and, if you have the measurement mic, change the input PEQ to a GEQ... I'd also add the FBX module... awe heck with your email address I could send you the modified .dwp, might be easier...which I have already modified..

    then I' put one bridged 2450 per sub, and one per low mid section (dual 15" on 725's) and one channel of each RMX1450 per horn...

    When you do the gain structure, leave the xover gains alone and use the amp attenuators to balance the system... as per this post:
    this way the limiter settings JBL provides will be useful...

    I guess that covers all the amps anyway so lets just forget about the 738's altogether...

    BTW since you are under powered by a lot on the subs I raised the HPF...on the preset I re-configured for you...

  • wow wow..that awesome explanation..
    This is it. Thanks so much for the help...

  • GadgetGadget Posts: 4,915
    So do you want the file I made up for you...if so I need your Email...

  • oh, yes...100% yes...that's should be great thanks a lot.
    Here my email: expoartmedia@yahoo.com
  • GadgetGadget Posts: 4,915
    Ok, the file is sent...When you get it (should be there long since)
    1. Create a folder on the desktop so you have some place to put and find the file, I called mine JBL SRX tunings
    2. From the email Copy and paste the .dwp into the folder
    3. Open (hopefully you have the Driveware GUI installed) the GUI and right click on the top blue bar...make sure the 260 is hooked up to the computer and communicating...
    4. From the drop down menu select "Import Program"
    5. Now you should have the "Look in" dropdown click the down arrow next to the address bar and and from that dropdown menu select "desktop"
    6. Find the JBL SRX tunings folder on the desktop and open it and left click on the "SRX725-728 triamp.dwp" click "open"
    7. The file is now in the 260... click the "Store" button on the Driverack
    a. From the "Store program" dropdown menu use the "Program Table Position" to select a location to store the new program. I generally use a location that is easy to find, and one that doesn't already have a preset I will need in the future...

    Your ready to fly...There is no real substitute for flattening the response of the speakers at this point and if your lucky enough to have and know how to use an FFT based measurement system do so now, otherwise follow these steps:
    Some further clarification can be found here:
    and here:

    If you've read and done all that you should be ready to rock !
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