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HELP Which outputs do I use when no crossover needed---???

mcalldpmcalldp Posts: 25
edited September 2010 in PA Connectivity
Okay, I am taking two outs from my A&H mixer to the Driverack and then two outputs from my Driverack to my QSC power amp wich goes to two JBL JRX125 cabs (two 15's and horn with built in crossover making them "quasi three way inclosures) That's it, no subs. So, my question is- which output on the Driverack do I use to go to the power-amp to make sure the full signal is getting to my FOH cabs since no crossover from the Driverack is needed in this configuration?
Highs? Mids?

I'm using it mainly for the EQ/Comp/Feedback control.

Thanks for any help, newbie here :-) Rack arrives tomorrow (Replacing Behringer Feedback Destroyer Pro which I'll use on monitor mix later) Already reading the manual today though and there doesn't seem to be a setup listed that isn;t using at least two outputs......

I'm thinking it's the two high outputs I should use but I can;t find anything to confirm that.... or perhaps settings that need to be set for this config as well....?
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Comments

  • DraDra Posts: 3,777
    Do this.
    Set up using the wizard (I believe the speakers are in there and maybe the amps) then... Before you hook up the amps, send signal thru the DRPA and see which outputs are lighting up.
    You will need to set the HPF to 45 or 50hz w/ BW18 to help protect the speakers. Also do gain structure as laid out in the Read Me section.
    (easier to learn by doing than just giving you an answer about which outputs)

    DRA
  • Thank u! the QSC power amp has 50 htz protection set already, do i need to set it on drpa too? Also, are u talking about a readme section on the forum or in the manual?
    Thanks again for your help cant wait to get the unit tomorrow!
  • DraDra Posts: 3,777
    On the forum.

    Do you know what the limiting structure of the amp is? I might be tempted to use the amp's 50hz and then set the DRPA's lower with a harder cut-off. Maybe Gadget will chime.

    DRA
  • GadgetGadget Posts: 4,915
    Which amp series its it? I'd recommend using the HPF on the driverack, that way we can verify that it's at least a BW18 filter type ESPECIALLY if your going to let them go to 45 hz...

    By Comp I assume your going to compress the whole mix... tell me more...

    Gadget
  • Playing original rock music (Pink Floyd/David Bowie in style) with guitar bass and electronic drums (V-drums_ all going through A&H mixer with tc voice live pro 2 for vocal effects, the signal then goes to a QSC RMX 2450 power amp and out to two JBL JRX 100 cabs (built in crossover 2X15 and horn in each)
    I imagine I'll have compression on the whole mix (one reason I am getting the unit) but I also have to hear how it sounds... having not uses a drive rack before.... I don't think it would hurt to have the protection on both the power amp and the drivrack(?) I'm looking forward to seeing what difference it makes in the system! I got the mic with it as well so I should have it up and running tomorrow after work, I'll be using it in various live situations so I need to become familiar enough with it to set it up quickly and save patches for different places I play around town. If you have any suggestions or thoughts throw them my way!
    In my mind I am expecting a clearer sound at higher volumes without feedback.....
  • GadgetGadget Posts: 4,915
    That can happen.. but you have some reading to do...
    viewforum.php?f=60
    there are lots of pertinent info there..
    and this:
    viewtopic.php?f=61&t=959
    where setup is discussed...

    The HPF in the amp isn't the way to go for making sure the speakers are protected from over LF excrusion...The filter type won't give the protection the DR filters will...and stacking them will have NO benefit...

    Even with the DRPA+ the auto eq process it is painful for the patrons.
    G
  • I will read that today, thanks for the links. I was wondering about the setup process at the local bar, if there are already people there, how loud is this pink noise part of the setup? Ever to loud to run it is my main worry. I guess its a must not only for eq but feeback protection.
  • GadgetGadget Posts: 4,915
    Well, the farther back the mic is the louder it is and it's REALLY annoying! If your doing a close proximity run it isn't THAT bad but then it's NOT taking anything in the room into consideration...

    viewtopic.php?f=60&t=2346
    This thread explains the auto eq process.. and explains that if you do an outdoor flattening session, that that alone will be a huge step forward... in ANY venue, even outdoors...

    The feedback suppression process is equally annoying but if the system is sufficiently flat then you will also have the benefit of no feedback as well...

    other auto eq posts...
    viewtopic.php?f=60&t=1617
    viewtopic.php?f=60&t=949
    viewtopic.php?f=60&t=953

    Gadget
  • Gadget wrote:
    That can happen.. but you have some reading to do...
    viewforum.php?f=60
    there are lots of pertinent info there..
    and this:
    viewtopic.php?f=61&t=959
    where setup is discussed...

    The HPF in the amp isn't the way to go for making sure the speakers are protected from over LF excrusion...The filter type won't give the protection the DR filters will...and stacking them will have NO benefit...

    Even with the DRPA+ the auto eq process it is painful for the patrons.
    G

    My God, a lot of reading today and only finding a lot more I'll be needing to do! So, I understand there is no extra benefit to having the speaker protection on the amp as well but do I actually need to turn it off? Can I leave it on and also use the DRPA+ as well- is the stacking bad or just no extra effect from the amp? If just no extra effect I'll leave the jumpers be in case I ever use it without the DRPA+ and forget to reset....
  • Gadget wrote:
    Well, the farther back the mic is the louder it is and it's REALLY annoying! If your doing a close proximity run it isn't THAT bad but then it's NOT taking anything in the room into consideration...

    viewtopic.php?f=60&t=2346
    This thread explains the auto eq process.. and explains that if you do an outdoor flattening session, that that alone will be a huge step forward... in ANY venue, even outdoors...

    The feedback suppression process is equally annoying but if the system is sufficiently flat then you will also have the benefit of no feedback as well...

    other auto eq posts...
    viewtopic.php?f=60&t=1617
    viewtopic.php?f=60&t=949
    viewtopic.php?f=60&t=953

    Gadget

    Thanks, I was reading about the outdoor session to get a flat EQ. I'm still trying to figure out the difference in using the auto then redoing with PEQ, it's not a step by step post. Maybe I'll get it once I have the controls in front of me.
  • GadgetGadget Posts: 4,915
    I'm still trying to figure out the difference in using the auto then redoing with PEQ, it's not a step by step post.

    I have moved away from that procedure of late, there just aren't enough PEQ's in the DRPA /PX platforms.. so I set up some general tone shaping filters ...Like one @ 50-60 hz one @ about 100 hz (for the subs to process the peaks in the box) and 160-180 hz, 300-400 hz with a broader "Q" (for room resonance) and another @ about 2.5-3.5khz or even a high shelf with a suitable slope for HF tailoring...
    G
  • DraDra Posts: 3,777
    Gadget wrote:
    I'm still trying to figure out the difference in using the auto then redoing with PEQ, it's not a step by step post.

    I have moved away from that procedure of late, there just aren't enough PEQ's in the DRPA /PX platforms.. so I set up some general tone shaping filters ...Like one @ 50-60 hz one @ about 100 hz (for the subs to process the peaks in the box) and 160-180 hz, 300-400 hz with a broader "Q" (for room resonance) and another @ about 2.5-3.5khz or even a high shelf with a suitable slope for HF tailoring...
    G

    Gadget, Even in your new "minimalist" approach you are putting your speakers in a better place to allow the Auto-EQ to do less work. :wink:

    DRA
  • I noticed, in my reading, in the 'Getting started' guide under the Gain Structure section- it mentions disconnecting the speaker cables from the power-amp. I've always heard that this will leave the amp with no load and is bad for the power-map and can damage it. Can someone confirm this is the correct step before I burn out a Power-amp?
  • GadgetGadget Posts: 4,915
    Most modern amps (quality amps) can withstand open circuit/no load runs.. some are even short circuit tested (crown) (QSC)...
    G
  • Ah, so my QSC RMX 2450 should be fine.
    So, for a QUICK start, I see running the wizard (my power-amp and speakers are listed according to doco)
    Then doing the Gain structure, use the PEQ for large adjustments but allow the normal auto EQ and Feedback detection to run for those main settings. Sounding right so far?

    Now, do I still need to run the auto eq/feedback stuff outside to get a flat response?
    It sounds like, ideally, I would still run these at new locations using the PEQ to further adjust but the sound level of running these makes it impossible to do in some situations... so, you just pick you standard saved flat response for the EQ section adjusting PEQ by ear as needed and do what for the feedback elimination?

    I did download the pink noise file so I will use that to do the gain structure after work today...... I hope I am extrapolating the main basics from all the info out there...it's a bit overwhelming so I really appreciate you all taking the time to comment and help!
  • GadgetGadget Posts: 4,915
    I know it's intimidating.. it has taken me YEARS to put it all together...and it's really only the high points of years of testing and experimentation various techniques and theories by myself and others here and around the world.
    o, you just pick you standard saved flat response for the EQ section adjusting PEQ by ear as needed and do what for the feedback elimination?

    Yes, but remember, whenever you use the auto eq indoors...you should use the outdoor flat preset to "see what the room is doing to the sound" and see if creative speaker placement and room treatment (like the band banner covering that heating duct that hangs above the right stack, and use eq only judiciously...even less volume is preferable to more eq...
    Now, do I still need to run the auto eq/feedback stuff outside to get a flat response?

    That is possibly the MOST important thing to have.. gives good starting points for rooms you cannot do any eq passes, and as stated above...

    Sounds like your getting it just fine...and yes, the more you learn ... the less you know..
    G
  • ha ha, indeed "the more you learn the less you know"! Well, I hope my system will be pretty fast to setup as I'm not running separate subs etc... and my equipment is in the wizard. Still, what do you do about running the sound for the auto feedback? Do you just let them all float and hope they find it during performance or do you say to hell with it and run the loud setup at the venue? Actually I wonder if most people run this or not as I can't imagine any local club owners being happy with us running some loud test noise!

    The one I have now (Feedback Destroyer Pro) just auto learns some and then has some floating without any noise generating test, is that an option with this unit?
  • GadgetGadget Posts: 4,915
    Ya but it's gonna clamp down on things it shouldn't ...I don't find the feedback suppressor is necessary when the speakers are flattened properly.. I have had idiot singers with wireless mics hanging from the light bars out in front of the speakers screaming at the top of their lungs and not had feedback :mrgreen:

    But yes, the driverack will work the same as the (Feedback Destroyer Pro) only better...
    G
  • UPDATE:

    Okay, with all of your wonderful help, I got the unit up and running. Setting the gain structure seemed easy but I wasn't sure about the little knob graphic it has you set in the wizard, seems it's supposed to be set to same place as your power amp knobs? But those change constantly.....little confused about that. ANYWAY everything was getting a good signal, I was a little distraught that the power amp started clipping at the HALF-WAY mark meaning I'm losing half my available power.

    The DRPA was set at 15 through the auto wizard using my amp and speaker setting. The manual mentioned having to fine tune it by a point or two but I think I had to drop the limiter from 15 to -5 or something crazy to get my amp to be able to open up without clipping. Any thoughts here? As for the EQ, I used the PEG to help with vocals and drums but to me the entire mix seemed to lose all bass strength. The bass sounds more like honky mids now.

    So, louder and clearer without as much feedback but loss of a lot of available power if I wanted to go louder and the bass is horrible. I didn't have to set it as full mix to the outputs anywhere that I saw... it seemed to understand that when I put all my info into the wizard and am running from the two high outputs to the power amp.

    Anyway, any thoughts on these two issues much appreciated and all of your time and responses thus far have been very helpful so thank you for that!
  • DraDra Posts: 3,777
    Have you read (and followed) the step by step instruction in the READ ME FIRST section regarding gain structure and limiter setting? If you haven't, do. If you have, something is wrong.

    Turning down the amp knobs DOES NOT reduce the output capacity of the amp. The amp can reach full power at virtually any setting IF the mixer can provide enough signal. That is the purpose of the gain structure exercize mentioned. To get the amp set to the point were the mixer is putting out IT'S max at the same point the amp is.

    The PEQ's generally are not meant for taming individual inputs (mics, drums, etc), especially if they have major problems, but for taming (correctting the general response of the speakers. By pulling out the rumble in a vocal mic with system controls, you will definately pull the bass out also. That should be tackled by the individual channel EQ. You may need to insert an EQ if the boards are not capable to get you what you need.

    DRA
  • Yes, I was using the instructions from the getting started thread. I downloaded the pink noise, played it form computer into channel, set the trim, got it so the signal was strong but not clipping. I made sure everything (compression etc...) was off on the DRPA and then, with speakers unplugged, raised my volumes on the QSC amp, got just over half-way and got cliping (red lights) so turned down about 6db according to directions, this put me at the half way point on the power-amps volumes. Then the instructions say "mark that point and don't ever go past it" and I'm thinking....I just lost half my power-amp volume? Something isn't right.

    I know the signal is good at the mixer.....the signal seems to be good on the DAPA (above 0 no clipping) but the power amp is showing the clipping lights way too soon for some reason and I am just stumped.

    Oh, For the PEG I used the settings suggested in another thread here that are supposed to just fine tune a mix a little nothing huge and I did think it was a bit of an improvement in clarity but nothing major happening there. So the bass (or lack of) and the amp headroom are the two issues that seem to still have me scratching my head.
  • GadgetGadget Posts: 4,915
    .I just lost half my power-amp volume? Something isn't right.
    Your missing the point... as Dra said you aren't MISSING anything... you are simply given a control that allows you to use that amp with a variety of different equipment and output voltages..when you send the signal from a consumer level piece of gear (-10dBu) you are sending a FAR smaller voltage to the amp than a pro level device sending +4dBu. So in order for the amp to be able to work with any technology, they gave them an INPUT attenuator. The larger the signal the more you MAY need to attenuate it...
    Oh, For the PEG I used the settings suggested in another thread here that are supposed to just fine tune a mix a little nothing huge and I did think it was a bit of an improvement in clarity but nothing major happening there. So the bass (or lack of) and the amp headroom are the two issues that seem to still have me scratching my head.

    PEG? PEQ maybe?
    As for the bass, or lack there of..if the tops are blowing away the subs.. TURN THEM DOWN TO BALANCE THE SYSTEM... It's not uncommon to need 10 times the power for subs that you have for the tops.. Consider the efficiency of the various elements.. the average sub woofer is less than 95 dB efficient.. while the horn is usallly MORE than 105dB efficient with the same input power.. so if you had the SAME amp driving the sub and the horns.. you would almost need to shut OFF the amp on the horns and crank the subs amp... make any sense?
    I know the signal is good at the mixer.....the signal seems to be good on the DAPA (above 0 no clipping) but the power amp is showing the clipping lights way too soon for some reason and I am just stumped.

    Again the power amp is only showing the clip light because it has NO MORE TO GIVE (except for the power to "let the smoke out") you are hitting the amps with sufficient signal to clip the output stage...simple as that.

    G
  • DraDra Posts: 3,777
    I am not supprised that you only got just above 50%. My PLX2's are about there and the 260 wizard (and I bet the DRPA wizard also) puts the 2450 at 37%, so don't worry in the least. What you get (if you do it correctly), is what it is. By the way 6db seems a bit extreme as a reduction, but better safe than smoke.

    DRA
  • Quick response on the subs, the JBL JRX has 2X15 and a horn with built in cross-over to send the bass to the lower speaker, I don't have any separate subs.

    Another thought, I do still have the speaker protection on in the dip switches for the amp, I can;t rember if they are set at 35 or 50 but I wonder if that is having any negative effect.

    With the mixer signal set the same, going straight to the amp, I can turn the amp up almost all the way before clipping. I put the DRPA back in the signal chain and the clipping as with the knobs just over half way up. Again the signal on the DRPA looks good both input and output are you saying this may be a change you would expect to see with the unit in the chain?

    Sorry, I did mean the PEQ! (not PEG)

    Well with any advice I get here, I'll get some more play time in on this unit and hopefully get it tuned in better. I think I need to do the outside auto EQ again and maybe even try the C option instead of the FLAT one to see if I like that EQ setting better in my system.
  • DraDra Posts: 3,777
    Louder without the DRPA? What does the PEQ and GEQ look like? Any boosted bands? Where is the x-over (filter) gain set?

    DRA
  • Dra wrote:
    Louder without the DRPA? What does the PEQ and GEQ look like? Any boosted bands? Where is the x-over (filter) gain set?

    DRA


    I'll have to look at it when I get home but I know there are some boosted and some cut bands in the GEQ from the auto EX process. The PEQ I simply boosted a couple frequencies by a HAIR (think 2 here) Is the X-over filter auto set in the wizard, is that what the nob graphic is? I think I set that half way up, it was at 33% and I threw it up to 50% maybe that's the problem, sending too much signal to the power amp from the DRPA.

    I can't say it's louder without the unit just that it clips much sooner with the unit so I didn't try turning it past this clipping point per the getting started instructions.
  • GadgetGadget Posts: 4,915
    DUDE!!! It clips the signal sooner because your sending LOUDER SOUND TO IT!!!!

    If you engage the limiter on the amp you will be cutting the available power by a lot...

    LOUDER isn't necessarily better.. especially if that sound is shrill high frequency sound like the JRX125's are known for...

    G
  • Okay, I don't know where I was amping up the signal on the DRPA but I went ahead and did a new program, ran it in a practice bedroom as I couldn't get everything outside right now. I went through the wizard redid the gain structure, chose "my band" rather than flat and for the PEQ I just added +! to 80hz, 2K & 3.55K

    Limiter is on, no compression the power amp is going to 28 out of 32 before clipping, much better. The sound is a little honkey still but I just need time to learn how to EQ some sections by ear better (I think)

    So, anyway, tonights setup is better than the first attempt which is a move in the right direction.
  • DraDra Posts: 3,777
    So, you did the structure with the limiter on?
    When you got to 28 (out of 30) what was the limiter doing? Hitting pretty hard, I assume. Just so you know, in the DRPA you can keep pushing the mixer output and blow right past the limiter and into the amp to clip it. Avoid that at all costs.

    DRA
  • GadgetGadget Posts: 4,915
    PEQ I just added +! to 80hz, 2K & 3.55K
    :?: :?: :?: :?:

    Um.... why? Those are not PEQ we suggested...
    The 60hz and 100 hz we suggest is for low BOOM
    The 160 hz and 350hz is for honky sound
    The 3k shelf is for HF sizzle/clarity
    and those are VERY broad "Q's" so they cover a lot of frequencies...(except for the 60hz and 100 hz which are 2 to 4 on the Q scale where the others should be closer to 1.0...

    When you choose specific amps the driverack assumes you set the amps as suggested. (it has NO idea if you have however)
    Limiter is on, no compression the power amp is going to 28 out of 32 before clipping, much better. The sound is a little honkey still but I just need time to learn how to EQ some sections by ear better (I think)

    why do you insist on the compressor when you aren't even set up properly yet?

    and why are you so fixated on getting to 32.. in stead of 28? IT DOES NOT MATTER WHERE THE AMPS CLIP>>> they just should NOT be allowed to! PERIOD!!!!!!! EXCLAMATION POINT :!: :!: :!:
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