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Newbie needs connection advice.

baw659baw659 Posts: 37
edited July 2010 in Connectivity
We have the following equipment:
2- Crown xti 4000
1- Crown xti 6000
2- JBL SRX725
2- Peavey SP118

What would be the best way to connect and configure that equipment? I am a newbie with biamping and bridging so the more detail the better. The JBL's have a biamp switch on them. Sorry for the dumb questions, I have been out of sound for quite some time and am trying to catch up.

thanks, Brian


  • GadgetGadget Posts: 4,915
    Run the amps in stereo.. since the mids and lows are 4 ohms each.. that would give you 650 watts for each horn, 600 watts for each midrange 15" and 1050 watts per 18" speaker...the power to the 15's and the 18" is low...but that's what you have...

    The outputs of the mixer to the inputs of the DRPA
    The HI outs of the DRPA to the inputs of the first XTi 4000
    The Mid outputs of the DRPA to the inputs of the second XTi4000
    The Low outputs of the DRPA to the inputs of the XTi6000

    Set up a 2X4 (fullrange tops and stereo subs) in the wizard...no real need to select the actual components you have since the actual tunings for the tops will be done in the XTi amps... for this you'll need to install System architect in to your computer and then you can automatically download and install the JBL tunings for the SRX725 speakers into the XTi amps...(which is VERY cool!)

    The Subs will be crossed in, in the DRPA @ 88.4hz LR48 since your low on power for the subs I'd suggest a HPF of 45hz BW24 or higher...the mids will be crossed in @ 91hz LR48, and Hipassed @1.15khz LR48. The horn is crossed in @ 1.12khz LR48. all the PEQ"s and delays will be handled by the XTi processing.. as well as any limiters you will want to set (especially the one for the tops...

    Now that I think about it.. the tunings will have one Xti 4000 running each SRX 725.. one channel will run the lows and the other the highs, and this way one 4 wire Speakon cable will be needed for for each side. One of the Speakon jacks on the back of the XTi 4000 will show that it is the one for bi-amping and will show 1+1- for the low and 2+ 2- for the high outs...

    Well.. digest all that and see what you think, we'll be around.. I'm sure you'll have more questions..

  • baw659baw659 Posts: 37
    So you are saying put the tunings for the speakers in the Crowns right? I thought that was what the DriverackPA+ was for. Is there a reason to do it in the amps over the driverack, not doubting your word just trying to learn.
  • GadgetGadget Posts: 4,915
    The Crowns have lots of Peq's to use and the Limiters are better... so let the DRPA help with flattening the system After you impliment the settings in the amps. Plus, you can simply download the info and basically plug and play...no jack panels to make .. one cable per speaker right from the amps..

    Technically you don't need the DRPA .. but it will make your system sound better in the end.. IF you have the measurement mic that is...

  • baw659baw659 Posts: 37
    I do have the mic. I appreciate your insight/help.
    thank you VERY much, Brian
  • GadgetGadget Posts: 4,915
    You can go to the JBL Pro website and get all the tunings and enter them directly into the Driverack if you wish...but because of the way the amps are made you'd have to build an amp rack panel. This way you can simply let the amps do all the work...and use one cable per top speaker...clean and easy.. I'd put a pretty stiff limit on the channel that runs the horn in each amp.. that 650 watts is too much for the horns. Unfortunately, you are very short of power on the subs and mids...
  • baw659baw659 Posts: 37
    Well my original idea was to run the 4000's bridged to the srx725's passive, then I started reading about the biamp possibility and wasn't sure which would be better. What are your thoughts?

    I downloaded the software and tunings and will work with that as soon as I get a pair of 12-4 cables put together.

    What would you recommend for power/amp with this setup.

    On another subject, The lights on the DRPA+ hardly ever move. Just the bottom lights for the channels come on is this normal?

    Thanks once again for your help, Brian
  • GadgetGadget Posts: 4,915

    A properly tuned and set up bi-amp setup will kick the livin crap out of a passive setup every time and twice on sunday :mrgreen: If done wrong it can be BAD...but the tunings are provided by JBL and the bi-amp method will allow you to help tame that "JBL" harshness in the highs...
    On another subject, The lights on the DRPA+ hardly ever move. Just the bottom lights for the channels come on is this normal?
    Did you do a proper gain structure?
    Remember, the DRPA+ is a digital device and does not need to be saturated like an analog device to get that "warm" sound.. and signal to noise is also not the same issue as analog.. if you notice, the ladders on the meter are mostly in 10dB increments...which is one reason you notice that.. just worry more about hitting the clip point of the DRPA+.. THAT is very bad... :roll:
    What would you recommend for power/amp with this setup.
    I have to assume that you are asking what you could do to better power this setup? I'd add an XTi2000 for the horns, run the mids with the 6000 and bi-amp the subs with one 4000 each. (if you had the dough, buy another XTi400 and you have redundancy in case of an amp failure.. you can revert to the above suggestions for a 3 amp setup) this would require a jack panel as I said, because it would require 2 amps for the tops, one for the mids and one for the horns.

    Note: The Xti series is not known as a great amp for subs...those that have tried all the amps(or have many of the different types) say that there is a BIG difference in the punch and tightness between them and the QSC, IT series Crowns, and most other (read this more expensive) amps. :|

    BTW.. 12awg 4 conductor wire is BIG and heavy..and hard to get into those speakon connectors...14awg is better and acceptable under 50ft. I do run 12AWG (2 conductor) on the sub cables and keep them shorter in length... the very best way is to have a dedicated amp rack on each side (or in my case one that is right next to the stacked together subs and a very short cable run...) and cables that are shorter...

  • baw659baw659 Posts: 37
    So you think a QSC or two would be better than another XTI on the subs?

    By a jack panel you mean because I have to come out of channel 1 on both the 4000 and the 6000 to +1 &-1 and +2 & -2 on a panel speakon in order to run one 4 conducter cable per side, I have an 8 outlet panel I could wire up. The JBL's are + - 1 on the lows and + - 2 on the highs biamped so I would take +-1 from the 4000 channel1 to +- 2 on the panel speakon and same on the 6000 to +- 1 on the panel speakon. Then wire the 4 conductor cable to speaker accordingly.

    I would bridge the 2 XTi 4000 sub amps correct?

    I really appreciate the help.
  • GadgetGadget Posts: 4,915
    Yes.. I think you have it...The single XTi2000 would do the trick if you aren't VERY serious about sub bass... but then you should have LABsubs, or something like the EAW949 or SB1002...Personally I run Macrotech 3600VZ and QSC 4050... but as I said the buzz is that if you want truly awesome sub bass.. The XTi's are less than stellar next to the "PLX" and "IT" series amps, and those from others ... but the best we have found is the Powersoft amps. Spendy but unbelievable performance to weight ratio...If weight and power draw and shear power are important.. the Powersoft amps are what I would choose hands down.
  • baw659baw659 Posts: 37
    Ok let me run this by you then.

    The SRX 725's bi-amped are 1200/2400/4800 @ 4 ohms on the lows and 75/150/300 @ 8 ohms on the highs. The subs are 1200/2400peak @ 8 ohms.

    2-xti 4000 bridged mono on the subs, they are 2400w each @ 8 ohms
    2-xti 6000 bridged mono on the mids srx 725 that would be 6000w each @ 4 ohms
    and a member has a Peavey CS 2000 and CS3000 which are 495w and 650 stereo at 8 ohms respectively which is what the ohms rating is on the highs are.

    I'm trying to make use of the xti 4000's we have even though you said they aren't much on the subs.
    Honest opinion please.

    Thanks, Brian
  • GadgetGadget Posts: 4,915
    Well.. the peavey amps will be fine for the tops, but you cannot run the XTi600 bridged into the mids because they are 4 ohms per cab... you COULD run 2 ohms stereo.. but I wouldn't... that would have only one channel of the 6000 being used ..and 750 watts per driver..

    Go ahead and use the 6000 stereo on the mids and the 4000's bridged mono on the subs.. you will probably not even notice the bass issues as you haven't got anything to compare them to...

    So, set up a stereo, stereo, (you will be asked that question twice) 2X6 in the wizard all custom amps and speakers (thats a bi-amp tops and stereo subs)

    Use the settings you got from JBL in the amps..

  • baw659baw659 Posts: 37
    I guess I wasn't clear I meant running 2 XTi6000's bridged 1 to each cabinet for the mids. Or is that still wrong, am I missing something on the bi-amp impedance?
  • GadgetGadget Posts: 4,915
    You have 2, XTi6000 and 2, XTi4000? Then use the 2, XTi6000 bridged on the subs, and the 2, Xti4000 on the mids...

    I was under the impression that you had 2, 4000's .. and 1, 6000...
  • baw659baw659 Posts: 37
    Yes we have 1 but have another available if I want to shell out the cash.

    Sounds good thanks!!
  • baw659baw659 Posts: 37
    Ok Gadget this is the last time I will bother you I promise.

    We are going with :
    2 XTi 4000
    2 XTi 6000
    1 Peavey CS2000
    2 Peavey SP118 subs
    2 JBL SRX725 mains

    Could you give me the setting/setup for this. I am taking your previous suggestion and bi amping the 725's with the 2 4000's on th mids and the Peavey on the horns. 2 6000's on the subs.

    There are no settings in the Crown or DRPA+ for the subs so I would like you opinion as to settings and wether they should be in the DRPA+ or the amps.

    Thank you VERY much !! Brian
  • GadgetGadget Posts: 4,915
    Are you in a big hurry for this Brian? Reason I ask is I'm just leaving to do ultimate Ozzy tribute tonight and a wedding tomorrow...perhaps Dennis or Dra could step in I won't be back till Sunday night...
    But hey.. it's really NOT a bother..
  • baw659baw659 Posts: 37
    It's cool we play tomorrow night but I'll wing it. Safe trip. Brian
  • GadgetGadget Posts: 4,915
    Go to the JBL professional site and look up "suppoprt", "Downloads", "tunings", and "SRX700 series" in that order...in the zip file locate the last file " SRX700 tunungs for dbx driverack PA vev..." open it and scroll down to the SRX725 W subs, there are the tunings.. you could also download the tunings into one of the amps and then just manually configure the others using those settings they provide for a single amp bi-amp...

    Good luck, keep us informed.. I'm off to weddingsville :roll:
  • baw659baw659 Posts: 37
    Well everything went real well. I put the settings for the 725's in the xti 4000's got the peavey sp118 numbers from peavey website for the xti 6000 settings and bam sounded pretty dang good. Those sp118's were thumping the heck out of that place. They belong to a memeber of the band. I have been looking at some JBL 118 or 218 subs. I ran the subs pretty easy because they weren't mine.

    Got my patch panel made up and some 4 conductor speaker runs for the 725's.

    I couldn't even get close to unity on the master, just way too loud! I had the 4000's and 6000's at about 75% and the Peavey CS2000 at about 50%. That seemed to take the harshess out of the tops and made the sound real nice. The amps kept the 2nd led on and flashed the 3rd every now and then.

    Thanks for your help and feel fre to offer your opinions on anything.

  • GadgetGadget Posts: 4,915
    The current "thing" is to tune the system to factory specs, and let the BE have access to the GEQ and nothing else.. It makes sense since the manufacturer has far more money to throw at tuning the speakers, (and a vested interest in making them sound as good as possible) and the equipment to do so...

    The SP218's are about the best bang for the buck in 2x18" front loaded cabs. They use the same drivers as the QW subs and sound pretty good. Yorkville makes some subs that are a good buy also. I have the LABsubs which are a DIY sub and MAN do they rock! But are a difficult build and very large/heavy.

    Glad we could help.
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