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DRPA+ Connectivity

ampeg610ampeg610 Posts: 4
edited October 2010 in Connectivity
Does anyone know if when hooking up JBL SRX 725's in bi-amp mode, no subs if you should hook the low or mid output of the DRPA+ to the LOW/MID amp? Right now I have 5 Xti amps on my system running a 2x5 configuration. I run a Xti 1000 on the HIGHS (stereo) of the 725's, a Xti 4000 on the MIDS (stereo) of the 725's and a Xti 4000 on LOWS for my JBL SRX 718's (bridge mono), a Xti 2000 for monitors and another XTI 2000 for extra subs when we run them. We have a few small venues we play and instead of packing in the 718's I would like to try just running the 725's and let the 2x15's pull the low-end work load. Just want to make sure before hand how to connect to the DRPA+. I have already configured the DRPA+ for the 725's and the amps I am using and no sub option, I just dont know what output to use on the DRPA+.

Comments

  • DraDra Posts: 3,844
    Think of it this way. Whatever you set up in the DRPA, is how it will output it. So if you set up a bi-amp with out sub, you are using the cab as a hi / low box, not a hi / mid box. Therefore, use the hi and low outputs.

    Now, having said that... if you have your rack hard wired and labeled as hi / mid / lo and you want to use the mid outputs as your 725 (only) lows, and want to avoid having to rewire everthing everytime, just make presets that give you what you want. For example, when setting up the 725 (only), set up a bi-amp with subs, but simply adjust the mid x-over / filter to have the HPF that you want for the cab to go lower and don't use the "true" low output on this set-up. Set another preset, also a bi-amp with subs for when you use subs and set the x-over / filters accordingly.

    DRA
  • GadgetGadget Posts: 4,915
    Just remember to set the hipass filter on the 725's no lower than the 3dB down point @ BW18 to protect the woofers...
    G
  • In response to Dra, yes I do have our rack prewired for the 725s, using 4 wire conductor so we only have to run one cable for left and one for right from the two amps (1000 highs and 4000 mids) from a 4 pole speakon that I mounted on the back of the rack for left and right. Then we run another cable from the other 4000 and chain the 718s. So to understand you correctly, instead of moving the XLR for the 4000 running from the mid out to the low out, you suggest I just reconfigure the crossover in the DRPA? I'm not too savvy with setting up the crossover manually so I don't know if I could do that correctly. Unless you could explain to me the correct way to configure it manually. Is it just as easy to put it on the low output of the DRPA? I agree with having to change that for each venue would suck and I would like to have presets for that kind of setup. It would make my life a lot easier.

    Now in response to Gadget. Is your recommendation based on if I create new presets? Or if I just run off of the low output of the DRPA? And as i stated above to DRA, I don't really understand a lot of the crossover settings like you suggested with the the 3dB down point @ BW18.

    We have had the DRPA less than 2 months so I am new to this and the band has given me the responsibility to figure it out because I am the most tech savvy. Any and all help that you guys are giving me is greatly appreciated. I have found that it is usually easier to get advice from experienced users that to try to figure out the users manuals.
  • DraDra Posts: 3,844
    Let the wizard set up 725 (bi-amp) with subs. Then enter the X-over section and go to the mid parameters. Change the Hi Pass Filter (Lo cut) and lower it to the desired point and BW18 slope. The wizard says 31hz, but that seems mighty low. You might want something around 40-45hz, but you'll need to experiment a bit. Now just forget that you have a low component (control) at all. Save that preset and name it appropriately. Use the regular connection for the 725's to the amps and speakers. Then set up the same wizard config for 725's + subs, but leave the mid section alone (for the most part). You may want to tweek it some.

    DRA
  • GadgetGadget Posts: 4,915
    What Dra said... but worded a little differently to avoid confusion...(so you don't end up having to rewire everything each time) Is take the very same preset you have for the 3 way setup, save it to another preset location...then select the mid crossover point and lower it to 40hz and change the type to BW18... mute the low outs on the DRPA. Now you can simply hook the same 4 wire (NL4) up to the tops and just not have the subs hooked up (actually you wouldn't even need to mute the outputs just don't turn on the sub amps...

    UNLESS you are going have a separate amp rack for the smaller gigs...

    The settings for the Bi-amp 725's should be in the wizard so setup should be a breeze.

    The BW 18 filter is a steep a steep slope meant to protect the woofer from over excrusion...(damage)

    The one problem is in stereo you only have 1200 watts per channel...that's 600 watts per 15"... not even the continuous rated output of the speakers.. so if your going to run that low you need more power (sub frequencies require more power) so I would bridge both the 4000's and run one on each cab.... if your going to do that you might want to just make up a preset for the bi-amp tops that would use only the high and low outputs from the DRPA.. simple enough to swap outputs on the DRPA to the amps... Then, if you set up the wires going to the jack panel on the outside of the rack with dual banana jacks, you could just unplug them from the one XTi4000's black and red outputs to the two red outputs on each XTi 4000 amp, and then set the amps to bridged operation. Then you could just let the wizard settings determine the HPF point for the subs.

    That is what I would do...
    Gadget
  • GadgetGadget Posts: 4,915
    Then set up the same wizard config for 725's + subs, but leave the mid section alone (for the most part). You may want to tweek it some.
    :?:
  • DraDra Posts: 3,844
    I meant that he might want to change the intersection of the sub to mid frequency, higher or lower than the wizard sets up.

    DRA
  • Thanks guys for all of your help, it worked like a charm. Now another question along the same line. If I want to send a mono signal out of the board to the DRPA+ can I still run my amps and speakers in stereo? That is how it is ran now. Not quite sure of the settings in the config wizard about stereo linked. I assume (Assumption is the mother of all f-ups) that if your sending a mono setting to the DRPA+ then all you get is a mono sound, but without rewiring the rack can I still leave it hooked up for stereo out of the DRPA+ and change the settings in it? Do i come out of the board mono and then split it to input left and right or leave it mono left? I don't know, maybe I'm just lost in all of this and attempting the impossible.
  • GadgetGadget Posts: 4,915
    No, but by nature the signal from the mixer is mono summed unless you use the pan controls...so why not just use both inputs and simplify.. otherwise you need a Y cable into the DRPA+
    G
  • DraDra Posts: 3,844
    ...or use the parallel mode on the amps. "Stereo" is just a word that means "2". It is easier to says "Stereo" than "Two channel mode".

    DRA
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