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JBL prx612m

djock12djock12 Posts: 47
edited March 28 in PA General Discussion
Hello, I haven't posted in awhile. I recently bought a pair of powered jbl prx612m speakers. Can i use my driverack pa+ with these powered speakers to fine tune them? If so, will that override the onboard DSP?

Comments

  • djock12djock12 Posts: 47
    These are 2 way speakers. Here are the internal DSP settings:

    Dynamic Control (Input): dbx Type IVâ„¢ limiter circuit
    Crossover Modes: DSP controlled. LF: 48 dB/Oct. filter slope High & Low Pass
    HF: 36 dB/Oct High Pass
    Crossover Frequency: 2 kHz

    Power Rating: 1000 W (2 x 500)
  • DraDra Posts: 3,777
    It will not override (as in turn off), but will change as you make changes. For example, if the speaker's DSP has a +3db boost at 2.5K and you cut 2.5K by -3db, you will have a net result of -0- at 2.5k (in other words, it will be back to the raw speaker in that cabinet response.

    DRA
  • GadgetGadget Posts: 4,915
    Yes you can use it, but no it won't over-ride the onboard DSP. The driverack doesn't have ANY idea if the speakers are powered, or not, and the JBL prx612 doesn't have any idea what your doing before the signal gets into it.

    You CAN however modify the way the prx sounds using the driverack and it's tools.
    G
  • djock12djock12 Posts: 47
    Could I use the info from this faq viewtopic.php?f=60&t=1193 as a baseline for my system? I'm assuming that the basic principals are the same.
  • GadgetGadget Posts: 4,915
    Yes, that is what I wrote it for.
    G
  • MctwinsMctwins Posts: 113
    Hi
    There is a new firmware update for the PA+ witch includes PRX600 series.

    http://www.dbxpro.com/PA+/firmware.php

    Thanks
  • djock12djock12 Posts: 47
    Thanks for the replies. I will definetly get those new settings and go from there.
  • GadgetGadget Posts: 4,915
    Remember however that they are only baseline settings. No Equalizations are likely to be provided. Perhaps Mctwins will plug in the preset and give us an idea what settings ARE provided..
    G
  • MctwinsMctwins Posts: 113
    HI
    I just checkt the PRX612M and there is no settings like GEQ or PEQ and X-over is in OUT mode. Only thing that is ON is;

    Live Filter Lift, 5minutes and
    Mode: Fixed
    Type: Music High
    Number Fixed 6

    What this now means :? . I have mine in OFF position.

    and

    Limiter will be set depends on where you set the knob when you insert the PRX600 series on PA+ and the OverEasy is 4.

    I am running mine in 2x4 config and I have set my knob on PA+ for PRX635 at 53% and 618S-XLF at 46% and this corresponds to what I have my knob at the backpanel of my speakers.

    You have only two-way so set the knob at 50% to start with with your speaker and 50% on PA+ and do AutoEQ and you are ready to go. There is no need for you to use PEQ, just use GEQ.

    In my case it sure sounds good :D

    Thanks
  • DraDra Posts: 3,777
    No x-over filters? :roll:

    DRA
  • MctwinsMctwins Posts: 113
    Hi
    There is no need if you are using 2x2 because there is onboard x-over filters in the speakers.

    I have 2x4 and here is the x-over set at highpass at 118Hz, BW18 and on the subs out.

    Thanks
  • DraDra Posts: 3,777
    Does is offer any thing if you select a 2 x 4 and bypass the speaker filters?

    DRA
  • MctwinsMctwins Posts: 113
    Hi
    No, you can't bypass the speakers x-over. It is powerd speakers.

    The only I have seen in 2x4 is with PRX635 as mentioned before 118Hz, BW18. On the sub is OUT

    Thanks
  • DraDra Posts: 3,777
    So you can't run the tops full range?
  • MctwinsMctwins Posts: 113
    Dra...
    Off course I can, just run OUT on PA+. There is no need to highpass at let's say 50Hz.
    Thanks
  • DraDra Posts: 3,777
    So you mean that the PA+ sets the sub low pass at 118 and the High's high pass at 118 by default. I guess that was confusing when I said "bypass the speaker's filters". I was assuming that the sub had a filtered output for the 612, and that is what you had done.

    DRA
  • MctwinsMctwins Posts: 113
    Hmm...

    No...

    When doing setup and choose PRX635 for the high and PRX618S-XLF for the lows it looks like this in PA+ x-over meny.

    Low; OUT
    High; Highpass 118Hz, BW18

    and it is 2x4 setting. Are you following me here.

    Thanks
  • DraDra Posts: 3,777
    So are we assuming that the PA+ "knows" (or is programmed to know) that the low pass on the sub is also 118 (or there abouts.

    DRA
  • GadgetGadget Posts: 4,915
    Hmmm I think this is all getting blown out of proportion...

    Select a 2x2 with most any powered speaker and the manufacturer will most likely default to the limiters and HPF of the speaker. There is no LPF on the hi outs...


    If a 2x4 xover is applied and JBL preset doesn't offer an HPF for the tops it's because in the vertical orientation the 612 falls off fast enough to not present problems for the crossover region, according to the JBL site the vertical orientation is 90 hz 3dB down.. I suspect it's somewhat higher...In the 2x4 setup you will be ALLOWED to set up like ANY OTHER 2x4, with full crossover function, HPF and LPF for the sub and HPF for the tops...even if they are set to out form the factory... remember, dbx will not usually "roll their own" setups.

    I usually cross 12" mains (even stout ones) @ 120 hz or so...it's just easier on the amps and the midrange clarity is better...

    Gadget
  • MctwinsMctwins Posts: 113
    Hi
    Well. I asume the DBX has been talking to JBL about the settings for the PRX635 and come up with 118Hz, BW18.

    The subs PRX618S-XLF has a freq range from 30Hz-105Hz(-10dB). There is no reason to use the x-over settings for the lowouts here.

    I have been tested this and that and when it comes to 2x4 mode the best performance is when using the lowsout and leave the x-over in OUT mode. Well, that's me.

    I can assure that the sound is good with the new settings.

    Thanks
  • GadgetGadget Posts: 4,915
    The OP and this thread are assuming a pair of PRX612... The PRX635 and PRX618 are Mctwins which he runs in a 2x4 mode... The 612, in vertical mode are said to be +-3dB @ 90hz (they have a 60hz "monitor position" +-3dB because of the coupling with the floor...

    The PRX635 has a 3dB down of 53 hz from the frequency plot that looks plausible...

    You'd actually be surprised how LITTLE communications there are within the Harmon group product skew.. it's all about the "cash cow". JBL was that animal in the past but not anymore, and since the operation moved overseas this hasn't helped.

    It's not unusual for JBL to overlap xover setups especially using BW 18/24 filter types, and some corresponding equalization. on my older coaxial 15" monitors I ended up with a 2khz and 1.8khz overlap @ the horn using BW24 filter type and a cut of about 4.5dB Q1.22 @1.9khz to smooth the response and even @ 119dB I can get the mic within 3-6 " from the center of the horn and have absolute stability...

    I would be surprised if the3re was however a spread like:
    SUB:
    PRX618S-XLF HPF out LPF 118
    PRX635 HPF out....

    is that what were talking about here..

    because I would NOT be surprised to see:
    PRX612:
    HPF out
    PRX618S-XLF HPF out LPF 118hz...

    Because what Mctwins said:
    HI
    I just checkt the PRX612M and there is no settings like GEQ or PEQ and X-over is in OUT mode. Only thing that is ON is;

    Live Filter Lift, 5minutes and
    Mode: Fixed
    Type: Music High
    Number Fixed 6

    What this now means :? .

    Is all predicated on the PRX612, and to answer your question as I already have Mctwins, is that NO speaker manufacturer is going to supply ANY PEQ or GEQ information on a fullrange product ESPECIALLY not on ones that are powered and with DSP....that would be like admitting that the speakers have flaws and that other manufacturers products are better. So it looks like were dealing with some "assumptions" that are not born up by the facts...

    Another thing to remember is that on powered subs we usually allow the subs to set their own HPF and limiting.. thus the "out" for the low frequency extension...

    So for clarity sake, lets assume nothing from this point on and try to be as specific with crossover numbers as possible I.E.

    PRX635:
    HPF 118 BW18 - LPF out (assumed on DRPA/PX HF outputs)
    PRX 618S:
    HPF Out - LPF 118hz BW18 (If this is incorrect Mctwins please clarify)

    I may be scarce here for a bit.. something terrible is afoot in the family...

    Be well everyone...

    Gary
  • MctwinsMctwins Posts: 113
    Hi
    It is incorrect, Gadget..there is no x-over settings for the 618S-XLF or 618S.

    Mine setup is like this in 2x4;

    PRX635 Highout; highpass 118Hz BW18 Lowpass OUT
    PRX618S-XLF Lowout; highpass OUT and lowpass OUT

    This comes up when I choose the settings for my speakers.

    I tried even with PRX618S sub and it is also OUT both highpass and lowpass but the only difference is on the highpass for the PRX635 is 118Hz, LR24.

    Thanks
  • DennisDennis Posts: 801
    Mctwins

    Here is a link to the subs' spec sheet... http://www.jblpro.com/catalog/general/P ... =365&MId=3

    The subs' frequency range at +/-10dB is 30Hz-105Hz but the actual useable frequency response at +/-3dB is 39Hz-93Hz. If you cross over at 118Hz, you will have a bit of a dip below the xo point. That sub will not make it all the way up to 118Hz according to the spec sheet. Also, the spec sheet gives 90Hz as a xo frequency which makes more sense.

    Dennis
  • GadgetGadget Posts: 4,915
    And the cool thing is you can try both at the flick of switch and see what sounds best!
  • OklaPonyOklaPony Posts: 48
    Just subscribing to this thread, mostly.

    Within the last month I outfitted a client with this exact setup (DRPA+, PRX618S-XLF X 2, PRX635 X 2) but haven't had the opportunity to hear it. He's a pretty savvy guy and says he's quite pleased with it but I'm anxious to get my ears (and fingers) on it. :D Maybe we should start a new thread dedicated to this rig?

    Also, Gadget commented on the info sharing / collaboration within Harman. I know they've undergone an extensive consolidation process over the last several months / year. Whether or not that has improved comms between the different groups I obviously wouldn't know but that certainly had to be one of the goals. I've always been under the impression that the whole PRX line was a joint effort of JBL, Crown, and dbx brainiacs.

    Perhaps jdragon will pop in this thread and give us the skinny on some of this.
  • GadgetGadget Posts: 4,915
    Well, you can ask... but realistically... they actually (dbx) only come here when I request them to (pretty much)... not trying to toot our horn here, but they are very busy on the tech lines and we have pretty good coverage of the issues here...and they know that I'll get them involved if needed. Besides this is a USER forum.. after all.

    They are very tight lipped about most anything to do with dbx.. or Harmon for that matter. I have gotten a few tidbits over the years but that is a confidentiality I have with those involved and I am sworn to secrecy on many of the matters... you would be surprised just HOW secret things are.. and how much difficulty there in getting inter divisional info...BTW they all have their own DSP teams and none of them talk much.. the one collaboration point is control software like System Architect...

    G
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