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Driverack 260 + QSC PL380

hooperhooper Posts: 5

My small system entails the following:

2 JBL SRX725's
2 JBL SRX718S's
2 QSC PL380's
Driverack 260

The flash update added in the newer SRX700 series speakers which really helped, but the QSC PL380 amps are not listed. Only QSC PLX is listed. What would be the best way to configure/maximize the PL380 amps? Right now I have both of the amps set for not listed or user defined. I've read some of the information on tweaking custom amps, but seriously not sure If the configuration is proper.



  • DraDra Posts: 3,777
    Since you have identical amps it will make things pretty simple. You need to do a gain structure. The details are in the Read me first section, the Start here. About half way down there are numbers (step by step instructions). Once that is done just select any amp (same for tops and sub). The wizard will set the x-over gains, then you can tweek from there if neccessary. Since you are using QSC PL's, I'd used the PLX3602 for your stand in, but it won't matter at all.

  • hooperhooper Posts: 5
    You know, out of all the years I've done sound and worked in bands, I don't think we ever got it right no matter how many girls took their tops off.

    But I do appreciate the response man. The PA sounds as good as can be, well being JBL is cheap now and don't use magnets in the speakers. The 700 series cannot even compare to the work done with the old SR series II stuff. But man you know how it goes. Do as you do, the best that you can do.

    Sounds is okay. Just didn't know exactly what to do with the new amps, but regardless, I'll tell you something... These QSC pl380's kick whompam ass. Even if not set exactly as what is required by specification. These amps will knock your speakers out of the cabinet. That you have my word on my friend. Sounding good, just didn't know if I could do better is all. Always looking for what is right, been told it's right, and still don't believe anyone around me. I'm always paranoid that something is going to blow up or give out in the middle of a gig.

    Thanks for your help.
  • DennisDennis Posts: 801
    The PA sounds as good as can be, well being JBL is cheap now and don't use magnets in the speakers.

    I don't have a high opinion of JBL old or new but light weight neodymium magnets would be considered an upgrade by most folks.

  • GadgetGadget Posts: 4,915
    Well I am NOT a fan of JBL... I have never liked the harsh raspy upper mids they generate and their attitude toward their \"less than 'A' level\" customers is crappy... at best, they insult the little guy with crap like the TR series speakers, and JRX crap and then put out the SRX line ... I have to interject here that I DO like the new Neo magnet-ed speakers..the definition, and clarity they muster is far superior to the old ceramic behemoths...I, as a rule, don't make good mid-ranges.. but as JBL speakers go the SRX 722 with the 12\" is about my favorite other than the VRX series...

    With an amp sensitivity question like you posted here we normally try and employ the KISS method... the thing is we have so many beginners and novices here that we try and go the simplest route since all this new digital technology can be very daunting...So, that said, the important thing to realize here is that speaker manufacturers rate speakers with the OPTIMUM amps for a given task, and amp manufacturers rate their amps at a \"this voltage\" (insert input sensitivity here) will give you the maximum output the amp can give without clipping...

    When 2, 3 or 4 amps of the same wattage are used on a given system, then we know that the subs are going to require the MOST power...so if we set the amps sensitivity the same on both amps in a 2 way system or as we said earlier all 3, or 4 in a 4way system, then we would need to send a MUCH lower level signal to the HF then the subs, and usually a lower level to the mids, and lo mids as well... this means that we have to use the crossover to do this. I usually hedge the sensitivity... in other words, if the subs are 95 db sensitivity, and the lo mids, 99 and the horns @ 106 (this is a typical mid grade setup) I will set the horns @ -7 db crossover gain, the mid @ -0- db typical and the Subs @ +4db. THEN I do the gain structure and if I end up with a lot of amp on the horns ( I typically run a 450 watt@ 8 ohms) amp for the highs, and I typically end up with the gains set @ less than 50% even with the 11 db difference in crossover gain on the DBX...

    It's ok to use either or both system to accomplish this, the goal is a system that is all talking the same language...(gain structure)

    I think you would realize more benefits in going 3 way and getting the setup from JBL and getting additional control over your sound, and getting added efficiency with this method as well...

  • DraDra Posts: 3,777
  • GadgetGadget Posts: 4,915
    Whats your question :?: :?:
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