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confusion sets in...inspector Gadget !?

trshottrshot Posts: 54
edited December 2006 in PA General Discussion
Here is my new system:
1-Crown CE2000 bridged-mains
1-Crown CE4000 stereo-subs
Mackie CFX 20 mixer

Old system:
2-Mackie SR1530-500w active-mains
2-Mackis SRS1500-600w active-subs
Mackie CFX20 mixer w/subwoffer output

I've programmed my DRPA as follows- mono-SR4725X-passive-SR4718X-stereo-CE2000-1.75v-63% gain-CE4000-stereo-1.75v-54% gain- I then stored it and it shows the schematic as it should a 1x4 mono system. I set the level switch at the rear panel to +4 as my Mackie CFX20 showed a mixer output as +4 (with a max of +20) I used L input, L (high) output, R/L (low) outputs. I've done nothing with any eq's.comps,lims etc. When I used my ipod as a test source I found that I was at unity before the system began to show good output,when I slid the master up to +5 I had considerable output and then to +10 where I was pinned on the mixer VU's and showing +10/15 on the DRPA input (no clipping) Although pinned on the mixer VU's I then maxed out the mixers master slide until I got a clip signal on the DRPA's LCD screen. here there was considerable volume..

Next I set up a mike, got my mike gain at about +7 on my VU. I usually set input gains around +4/7. I then spoke in the mike and there isn't a lot of voice output as compared to my old system. I was shocked by this, so I got creative and compared old and new speakers. I left everything set as mentioned above thru the mixers L out. I then took the R out to my Mackie SR1530. It's a 3 way 500w (300L/ 100M/ 100H con-fig) active speaker. I set my mixer master at +10 and panned left and played the ipod. There was VERY little output from the JBL/Crown system. I then panned right and POW the single Mackie smoked a 4 way setup with killer sub base!! I then did the same with the mic and got the same result great vocal power/presence with the Mackie and poor response thru the JBL's

Did I do something wrong with the DRPA set up? Is it normal to be way up past unity with a DRPA in the loop? As I've mentioned before, I'm new to this and The only PA I've used was my active Mackie set up. I would think (hoped) the JBL set up would destroy the Mackie set up based on more power,more head room(?) top of the line JBL's known for their live sound the DRPA and better x/over separation!! Any ideas?

As always thank you..

Tom Donovan
Breaking Point


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    GadgetGadget Posts: 4,915
    I'll have to get back to you for more but did you use the xover gain controls on the DRPA..? when you set the input sensitivity on the amps you limited their output so that a stronger input signal was necessary.. The DRPA has no input control and the output controls are the xover gain controls. Or you could just turn the amps up a bit to compensate..
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    trshottrshot Posts: 54
    Gadget :D

    1st-thanks for your response and offer to help..

    2nd- I'm a drummer not a soundman, however I do the sound for my band. I'm a quick study, forgive me for any \"unknowns\" that may come your way..

    3rd- I spoke with Mike Hunter at dbx. He walked me thru my system program.It was a match to what I already had as noted in MY first post He also had me make some other changes as well. Not having pink noise we used music thru the tape input to establish a matched gain signal with the mixer,amps and DRPA at unity. I will attempt to give you all that we did..

    Here we go-I orignally set the amp gains at the settings the DRPA showed in program mode. These are listed in 1st post. I thought because my amps were listed I would not have to perform the \"setting gain structure\"
    Mike walked me thru what was a gain setting procedure. He had me at a clip threshold with the music signal at the mixer.I turned up the amps gain untill they clipped, turned down gain untill clipping stopped. next I turned on both high and low limiters with over easy off. I then turned the thresholds up to 20db (clipping)I adjusted the low threshold at -2db and the high at 8db (no clipping)In the end I was right where I was before we started with the amp settings.

    When at xover it reads-L-35.5hz BW12 -3.0db H-100hz BW18 -0.3db

    With my Mackie gear I hit +7 (output vu) around -5 & unity on mixer master volume. We set mixer at this setting while playing live, I can push more but loose headroom and be at the brink of protection mode. at this setting and just one SR1530 set up in the studio(12x15) It's loud as hell and the floor as well as my pant legs are shaking with sub/spl waves The jbl SYSTEM lacks severly at the same setting. If I go right to the top of mixer volume past +10 and it is very loud at the mains but I feel the subs are lacking the hit as compared to the one Mackie. Is is normal to go unity upwards of +5 or more ?

    It's a bit long winded, i just wanted to try to give you as much info as possible.
    Did this make sense, I hope I answered your question..

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    trshottrshot Posts: 54
    Gadget-Mr Wizard-dbx God

    After I posted the xover readings, I thought about it and what you said so I returned to the DRPA hit xover and brought up the db output on the subs from-3.0 db to 9db on the lows and from -0.3 db to 12db on the highs...and Cracked a window (just kidding) wow, no I meant WOW!! Could have gone more maybe, there was no clipping at this level, but being a newbie I did'nt want to damage anything..
    I'm surprised a dbx tech missed this..
    Given everythig I posted can you help/guide me to what you think I need to set the DRPA at, Limiters, compressers, output levels etc? Also, before I get a RTA mic, whats your take on auto eq where I'm going to set and forget the board for the most part?

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    GadgetGadget Posts: 4,915
    Well there are those types that would tell you that using the amps input attenuators @ the correct input sensitivity is the only way.. this might be true IF the system is carfully designed to have optimum power across the sprectrum.. Its a liottle unreasonable eith thrown together systems with mismatched components and amps...your better off to let the gain structure determine the amps final gain settings...

    As for the rest of the stuff..Skip the compressors.. use compression on a per channel basis.. Limiting is pretty good...but DRPA does not posess brick wall limiting. Set a pretty hard knee 8-9 and bring the threshold down with the system at full tilt boogie...till the threshold just starts hittong.. then any further attempts to increase the volume will be met with resistance.. the higher the knee setting the more audible the limiter action ill be.. and the harder it hits the more audible it will be...

    As for the Auto EQ I have provided volumes of info at the other site .. the one thats listed above as 'former forum'.. read all the tutorials and user submitted white papers...That should get you started

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    trshottrshot Posts: 54

    I assume now that the gain settings are right as there is no clipping unless I go near top of the mixer slide.

    when I was in xover mode and changing the db level am I going to hurt anything where I increased it up to the levels in last post? As I mentioned when I did this I woke up the pa 100% without clipping. Did you suggest the 8-9 hard knee setting because of this db increase or just as a overall protective measure?

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