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MRX 515 and 518 Help

jlbassjlbass Posts: 14
edited March 2008 in PA General Discussion
I just purchased new JBL 515 and 518's and noticed that those speaker presets are not in a new DRPA I just purchased. How do I set these speakers up in the DRPA to function properly.....Thanks for your help....JL

Comments

  • GadgetGadget Posts: 4,915
    No, and you won't find any tunings for full range speakers that you can't Bi-amplify... from ANY manufacturer... Those are powered speakers...What exactly are you asking for?

    I went to the JBL site and looked up the speakers and found this...
    Recommended Crossover: 80 Hz, 24 - 48 dB/octave

    Is that what you wanted?
    Gadget
  • Actually, the PRX series are the self-powered ones G... ;)

    The MRX are passive. From the specs I read on the JBL site, they look similar to the MPro series...as I think they replaced them in the lineup.

    Will confirm.

    C
  • DraDra Posts: 3,777
    I think what most people hope for (myself included) with \"speaker tunings\" is all the post PEQ settings to avoid having to \"flatten\" the passive cabinet for the base line.

    DRA
  • DraDra Posts: 3,777
    I think what most people hope for (myself included) with \"speaker tunings\" is all the post PEQ settings to avoid having to \"flatten\" the passive cabinet for the base line.

    DRA
  • GadgetGadget Posts: 4,915
    Hmmmm,
    Well, he didn't specify which model so it could be either...Its still a non bi-amp cab...either way...

    Dra... you will never see PEQ settings to flatten a speaker that is not bi-amp type. Those PEQ settings and polarity and delay settings are what make up the crossover and replace the passve crossovers... If a passive crossove/speaker requires post Eqing its probably a bad design to begin with...
    G
  • jlbassjlbass Posts: 14
    Gadget

    The speakers I have are the JBL MRX 515 and 518S. I just purchased the DRPA yesterday and I've been through the Users Manual 3 times trying to figure out the best way of setting up the crossover for these speakers.

    Honestly, I'm surprised that with the new MRX line of speakers the configuration was not in the Wizard?? Since I can't use the wizard can you help me walk through the steps of setting up these speakers in a 2X4 mono configuration?

    Finally, I will be running the speakers using two QSC PLX 3402.

    Thanks for your help!
  • DraDra Posts: 3,777
    Every cabinet That I've seen a aeno... (whatever) chamber response plot for has those 3 db humps and dips of varying widths. That's what I thought the PEQ's were for, to fix those. I've looked at the Elite and Unity processor settings that you've said you've use as a starting point. They both have full range tweeks ( the U15 has a 180 hz honk that takes a 13db cut to fix). Am I wrong, or am I missing something?

    DRA
  • GadgetGadget Posts: 4,915
    Jlbass
    I guess you didn't get my point... in a passive speaker there IS NO reason to have tunings since they are passive... that means that the crossover is inside the speakers. What you want is a crossover between the subs and the tops... in an ideal world manufacturers would supply those things like that but most don't... BUT I DID... I looked up your speakers and they are on the JBL site and they recomend 80 HZ with a fairly steep slope... 24 -48 db/octave...

    with that in mind:
    in the wizard set up a 2x3 or 2x4
    select all custome for speakers and amps selecting from the menu's...
    as for the sensitivity settings... the gain structure as per the back of the manual will set that ...
    set a HPF of 45 hz @ BW 18
    set a LPF of 80 hz @ LR/24
    thats the subs
    Set an HPF of 80 hz @ LR 24
    the LPF is out... that means there isn't one so the speakers are going to be allowed to do whatever they can do HF wise...
    do a comprehensive gain structure as per the back of the manual
    use the volume controls of the amp with the loudest sound to turn that component down till the tops and subs match nicely.
    Play some good fullrange music and sweep through the POST xover delay till you hear the sound tighten up...(you'll be delaying the tops) IF the speakers are front to front lined up I'd guess you'll end up around 7-10 ms.. If you want to do Auto EQ I recommend you read my \"new indoor method\" or do one stack outdoors.. also read Mikey Kovachs White paper all in the\"Former Forum Home\"



    Dra,
    Yes you can use them for that.. but truthfully those plots are a joke...In a perfect world all speaker components would be matched and ideal... they are not. realistically every driver, and speaker exhibits its own characteristics and each cabinet is a little different if its made with wood...That plot is for that speaker on that particular day... The only way to really find out what a speaker is doing is through measurement and not with an RTA based system I might add...Something like SMAART or some other FFT based system that takes time and phase into consideration, not just frequency based amplitude. Every speaker is going to exhibit some of that, and its a panacea to think you can get totally flat response across the spectrum. Remember that with real music there are so many variations in amplitude that you couldn't really detect a 3db difference in a particular frequency in the heat of battle anyway... there is more variation than that in the music itself.
    Gadget
  • jlbassjlbass Posts: 14
    Thank you Gadget...You explained exactly what I needed. I will give your setup a try today and will let you know how I make out.

    Once again...I appreciate all your help! JL
  • I have the same JBL cabinets..and the DRPA DOES have the speaker tunings in it. It sounds as if you dont have the correct version. However, you will have to send it in to DBX to get the version upgrade...which really is a damned shame that one cant do it via USB or MIDI. Then again, there arent ports for it on the DRPA
  • fazmanicgfazmanicg Posts: 10
    I have the MRX 518s as well. They are in the wizard. Sounds like you got a unit that was sitting around for a while. The firmware upgrade will include your speakers.
  • GadgetGadget Posts: 4,915
    Guys.... this post is almost a year old...
    G
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