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SETTING SUGGESTIONS?

gta214gta214 Posts: 4
edited November 2009 in PA Configuration Wizard
Hey guys looking for any good setting suggestions for my Driverack PA :?:

With the following equipment I'll go for a 2-way system for now.

2-JBL SRX725
4-Cerwin Vega EL-36b

1-QSC RMX5050 amp
1-JBL MRX1200 amp

Other extra info I have a DBX 31ieq for the main mix and I'm runing 2-DBX 166xl after the pa x-over as a 2-way system as a speaker protection. I don't have the RTA mic for the drive rack at this point...

I might use the QSC amp to drive my 4 Cerwin subs & the JBL amp to drive my SRX mids or vise versa but not sure at this point.

I will be running this system for bands.

Thanks in advance :D

Comments

  • GadgetGadget Posts: 4,915
    your under powered...even with the 5050 your still only feeding the subs 1250 watts and the mains under 600 each... Thats not much...Which driverack?
    G
  • DraDra Posts: 3,777
    gta214 wrote:
    Hey guys looking for any good setting suggestions for my Driverack PA :?:

    :D

    8)

    DRA
  • GadgetGadget Posts: 4,915
    Ok, so we've already determined that I'm blind..."it's a bitch getting old...and I'm well into that...so where's your 2 cents worth...smart guy..
  • GadgetGadget Posts: 4,915
    What is this amp.. the MRX1200? for any reasonable setup that is something needed...
  • DraDra Posts: 3,777
    Nothing on the JBL site or google for a MRX1200.

    SRX725 - 1200w / 2400w / 4800w 99db sens 136db peak each
    EL36 - 250w / 500w / 1000w (3" vc) 106db sens 134db peak each

    rmx5050 - st 1100 (8)/ 1800 (4) / 2500 (2)
    - br 5000w (4)

    Based on sensitivity (spec) you'll need a 4:1 power ratio, tops to subs.

    DRA
  • DennisDennis Posts: 801
    The Cerwin Vega EL 36B is rated 500W program and 1000W peak (8ohms). The QSC RMX5050 puts out 1050W FTC per channel into 8ohms and 1600W FTC per channel into 4ohms. 2 subs per side would create a 4 ohm load with 2000W peak power handling capability. That being powered by 1600W wouldn't be the worst thing in the world.

    What the heck is a JBL MRX1200???????

    Dennis
  • DennisDennis Posts: 801
    Dra, your amplifier specs are EIA (Consumer) specs.

    Dennis
  • DraDra Posts: 3,777
    Yeah, I know. I lean to the safer side (Higher rating) for speaker mat(ch)ing.
    Most folks at Harmony Central like no more than the continuous rating of a speaker fed to it. Most folks at PSW like no less than program and lean to peak.
    I like some, lean to...it depends. 8)
    I have melted vc's with program power (w/ HPF @ 40hz).

    Q: Can you power a 20w 1" horn driver on an RMX5050 with a full range signal w/ attenuators at -0-?
    A: Yes.

    Q: Can you power a 20w 1" horn driver on an RMX5050 with a full range signal w/ attenuators at -0- and 4v of input?
    A: No.

    DRA

    PS- not directed at anyone, by the way. Just felt like ramling.
  • DennisDennis Posts: 801
    Dra, you are confusing FTC and EIA amplifier ratings with Continuous/Program/Peak speaker ratings...two different animals.

    Dennis
  • DraDra Posts: 3,777
    I know that EIC is (usually) a 1K tone and that FTC is full band. My safety statement still stands since EIC is higher watts. If EIC is 600w and FTC is 550w, then if a speaker is safe on 600w, then for sure is safe on 550w. (caviots omitted) That was my point.

    DRA
  • GadgetGadget Posts: 4,915
    I think something happened to the
    I like some, lean to...it depends. 8)
    I have melted vc's with program power (w/ HPF @ 40hz).
    program power... voltage sag, compression/limiting... something OTHER than good clean power happened here... I see it all the time in the re-cone business.. my guess ... bad power...and the demands of that rap crap on amp power... add to that fatigue on the voice coils from years of service...the surrounds weaken the spider sags... then the cooling is compromised...

    I have never had a problem with too much power...I have had trouble with too little...
    G
  • DraDra Posts: 3,777
    [/quote]

    I have never had a problem with too much power...I have had trouble with too little...
    G[/quote]

    The response you would get on HC (not a good arguement) and in a snide & huffy tone, "Then every time you turned DOWN the volume you'd blow a speaker."

    100w / 200w / 400w speaker with pink noise applied through amp at max output (non-clipped / clipped (2x output))

    25w amp ) :D / :)
    50w amp ) :D / :)
    100w amp) :) / :(
    200w amp) :( / :x
    500w amp) :x / :evil:
    Or something to that effect.

    For regular Rock & Roll, country, etc and unclipped amps you possibly would get all smiles.

    Again, it all depends. If it's loud enough and sounds good and the meters are not pegged and the amps are not clipping at all, there is no such thing as underpowered. Underpowering is when you need 6db more output from the speaker (which has 9db more to give), but the amp can't give any more without clipping. It's symmantics (sp).
    It's not the power of the amp. It's the power coming out of the amp.
    Potential energy doesn't kill speakers. Kinetic energy kills speakers. :mrgreen:


    DRA

    PS - What was this thread about?
  • GadgetGadget Posts: 4,915
    Perhaps it was the "semantics" :wink:
    The response you would get on HC (not a good arguement) and in a snide & huffy tone, "Then every time you turned DOWN the volume you'd blow a speaker."

    That doesn't even deserve a response...I would definately like to see them postulate that crap on the PSW...that whole HS/GC/SA sales crap doesn't fly here...

    I guess that since Crown, QSC, Lab Gruppen, and Camco to name a few, and EAW, JBL, NEXO, Meyer, Adamson, and d&b audiotechnik all specify 2 to 4 times the PROGRAM power rating (NOT the RMS) for speakers... I assume that the conversation would be very short and VERY one sided...
    G
  • gta214gta214 Posts: 4
    I'm so sorry its the JBL mpx 1200 it was late night lol thanks for all the replys I didn't expect that much but i still did not get any Setting suggestion for my setup on the Driverack PA its not the 260 its just the "Complete Eq & Loudspeaker Control System" :)
  • DennisDennis Posts: 801
    You didn't get any suggestions on DR settings because we were busy fighting amongst ourselves and forgot about you completely. I would say that 80Hz LR24 would be a good xo point between the JBL's and the subs but Dra and Gadget will tell you that 100Hz LR24 will be better. This will start another fight and we will forget about you again.

    The JBL MPX1200 is underpowered for your application but still do-able. Another RMX 5050 would do better. Or get another MPX1200 and use one bridged on each pair of EL36 and use the existing 5050 on the JBL's.

    Dennis
  • GadgetGadget Posts: 4,915
    Ya... so.. you didn't provide accurate amp info and we've been here chewing on each others arms waiting for something to go on...That amp is NOT one we would know anything about and still know very little about...

    So I found 800 watts @ 8 ohms? is that correct? well... if it's true, and Dra's petrifying HC predictions tell us that 800 watts (on a speaker that is rated 1200 W / 2400 W / 4800 W right on the JBL site :shock: ) that 800 watts is SAFE :lol: .... not really...that isn't enough to get those things going in full-range...BUT thankfully were not going to be letting this go fullrange without the 5050! right?

    Therefore...as Dennis so aptly put it... we dis-agree a lot... the 80 hz he suggested would perhaps serve well on a system that is properly powered... (I would however like to know what his theory is on placing the xover right on top of the kick primary 1st harmonic frequency :?) as in his recommendation of another 5050...for the tops...but it will also work for a system where the subs aren't "crankin" all the time, and since the subs can produce 300 hz (at who knows WHAT efficiency, as there isn't a frequency plot for the sub to be found...)Heaven knows horn loaded subs get honky about 120hz...so there are only a few real possibilities and they are ALL really easy to compare with the driverack...

    Try 80 hz, try 100 hz try 118hz... and anything in between... if you want to try overlapping the frequencies use BW24 filters... LR 24 works well for adjacent frequencies with no overlap. Steep filters like BW18 are best for HPF's on subs, and LR6 is a good filter if your going to use a LPF on the horns as it has less frequency skewing ...
    have fun good luck!
    so... keep us informed!
    G
  • DennisDennis Posts: 801
    I believe the JBL box is 4ohm and the JBL amp does 1200W into 4ohms....not great but better than 800W.

    Gadget, on a number of occasions, you have brought up 80Hz being " on top of the kick primary 1st harmonic frequency" but I haven't got my head around the downside of the xo point being there.

    Dennis
  • GadgetGadget Posts: 4,915
    Dennis, et all
    I'm tired and most likely not thinking all that acutely...but as I recall, the kick drum 1st harmonic normally falls between 60 and 80- hz, right? When you read many of the articles about recording and or producing a kick drum they use typically, 80hz... Peavey... in the "boundary cancellation" article posted here uses 80 hz...I know you too will acquiesces to working that area...

    Well, if we were talking about 60 hz that would be one thing, but were not....really...that's typically too low a frequency. However, when you specify a more accurate kick frequency of 75-80hz and put a crossover on it you are landing on THE one ..ONE note wonder of the system...the one and ONLY one note wonder worth fighting for....So, with THAT important an element of the sound doesn't it make sense NOT to place the crossover point on top of such an important hallmark?

    I mean...you know what a crossover point can do to the sound....why place it on one of the most important elements of the mix? For me a few hz north or south of 80 helps steer clear of the kick impact...that's all I'm talking about :|

    314.gif
  • gta214gta214 Posts: 4
    Thanks so much for all the feedback I will try your suggestions for this weekend gig.... :) & sorry for making you guys fight jijije :lol:
  • GadgetGadget Posts: 4,915
    Awe heck this ain't nuttin...emot57.gif


    you outta be around when we start on blose..10_9_2061.giferrrr.bose

    32.gif

    carin and sharin...AddEmoticons04249.gifthats what were all about here on the love network...




    Emoticon-3.gif
  • DraDra Posts: 3,777
    GTA,

    You have a couple of issues to deal with.
    You have 4) mid 15"s and 4) sub 18"s - a negative. (balance)
    The subs are 7db more efficient - a positive. (Although it could be above the desired x-over point)
    The subs gain 3db by coupling sub pairs and maybe 6db (total) if all 4 are clustered together.

    I think you are going to have to try different configurations with x-overs and amp use and pick the best.

    Here is some math.
    Per speaker / no coupling factors included. SRX are capable of 136db. No spec for CV, but probably 137db.

    RMX stereo on SRX - 1800w / 131db
    RMX bridged on SRX - 2500w / 133db
    MPX stereo on CV - 600w / 133db
    MPX stereo on SRX - 1200w / 130db
    MPX bridged od SRX - 1600w / 131db
    RMX stereo on CV - 900w / 137db (rounded up)


    DRA
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