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use the driverack PA with just one amp?

DJCDJC Posts: 8
edited March 2009 in PA General Discussion
hello everyone

i need a little advice, i am thinking of buying a driverack pa to use with my system.

can i use the driverack pa with just one amp?

i have one logic system LS115 sub (600w@4ohm) with a pair of logic system CM12 tops (400w@8ohm) and i want to power these through my chevin A1000 amp which has 2 channels, each giving 600w@4ohms.

could i run the sub through the low output of the driverack and the tops through the high? each one going into a seperate channel of my amp?

hope this makes sense, any advice would be cool.

cheers

Comments

  • GadgetGadget Posts: 4,915
    Most certainly...that is a 1X2 setup...even 2X2 would work, (just use 1 side) and yes, the sub would come out of one side of the hi outs, and the sub out the left mono out...

    I think you would like it...the PX might be just the thing if you don't foresee needing any delay...

    Gadget
  • DJCDJC Posts: 8
    thanks for the super-quick reply dude!

    i thought the PX was for powered speakers?

    i am pretty new to this and have only just bought the logic pa.

    i spoke to the technical dept at logic and they told to make sure i didn't send too much low range to the cm12's or they would blow. they recommended i use a crossover.

    the driverack seems as though it's exactly what i'm looking for.

    are there any presets on the driverack for logic system speakers?

    cheers

    DJC
  • GadgetGadget Posts: 4,915
    :lol::lol::lol::lol:
    No my friend...but fear not! We can have you up and running in no time! :wink:
    As for the PX it is a 2 in 4 out that has all the same filters as the DRPA but no delay (for speaker alignment) Don't get me wrong... delay can make a real difference if set properly... the PX also comes with the measurement mic...

    If you really want it all... get the 260! It really IS all that!

    G
  • DraDra Posts: 3,777
    I need to correct a typo by Gadget.

    the sub would come out of one side of the hi outs, and the sub out the left mono out...

    Should say \"CM12\". You probably figured that out, but wanted to make sure.

    DRA
  • GadgetGadget Posts: 4,915
    :roll: oops :roll: You just LOVE catching me in a faux pas don't you :lol:
  • DJCDJC Posts: 8
    thanks for the help you guys.

    so the hi-outs will output both high and mid signals to the CM12's?

    DJC
  • GadgetGadget Posts: 4,915
    :roll: Ok, NOW you have me confused :roll:
    Granted.. I could find VERY LITTLE about \"Logic System\" speakers at all...
    BUT I did find the CM15...and it says
    The Logic CM-15 cabinet is a high-quality full-range cabinet
    That means that the cabinet is NOT Bi-amp capable... now when you indicated :
    i have one logic system LS115 sub (600w@4ohm) with a pair of logic system CM12 tops (400w@8ohm)
    That told us that you would be needing a crossover for a 2X3....meaning .. a normal \"stereo\" system with mono sub ..but the DRPA and the PX have no \"sum\" capability in the hi, and mid outs, so we just 'use' one side ...

    So, we would:
    1. Set up a 2X3 crossover
    2. Send a summed signal from the source, a mixer I assume? To the left input of the DRPA/PX
    3. From the LEFT Hi out to channel 1/A chevin A1000 amp
    4. From the left mono low output of the DRPA/PX to channel 2/B of the chevin A1000 amp
    5. The 2 tops out of the chevin A1000 amp channel 1/A
    6. The sub out of the chevin A1000 amp 2/B output...
    7. Implement a 5 hz BW 18 hipass filter for the sub
    8 Set a 120hz LPF @ LR 24 for the tops
    9. Set a 120hz HPF for the CR12's

    Now you have the tops protected against too much low end, and doing what they do best...the sub doing what it does best and minimal interference in the crossover region.

    Does that make sense?
    G
  • DJCDJC Posts: 8
    that is exactly what i want to do!

    i have emailed you the spec sheets for my gear, i really appreciate all your help.

    DJC
  • DJCDJC Posts: 8
    please forgive my ignorance, but what does 'sum' mean?

    DJC
  • DennisDennis Posts: 801
    \"please forgive my ignorance, but what does 'sum' mean?\"

    Stero L and Stero R are \"summed\" into a single line out or a mono signal.

    Gadget - is item number 7 above a typo?

    Dennis
  • DraDra Posts: 3,777
    No, those subs are flat to 2hz. They put the lab subs to shame. :lol::lol::lol::lol::lol:
    Gadget is having a bad couple of days. Ain't it great?

    DRA

    PS - DJC, he meant 50hz, I'm sure.
  • GadgetGadget Posts: 4,915
    :roll: funny :roll: that should read 45hz... :oops: thanks Dennis...
  • DJCDJC Posts: 8
    does the drpx work in exactly the same way as the drpa?

    is the number of outputs the only difference?

    if so why does it say its for powered speakers?

    will the rta mic be useful for me?

    cheers

    DJC
  • GadgetGadget Posts: 4,915
    As I said there is NO delay, 4 outs v/s 6, and one other benefit is the PX has FET outputs so it doesn't have the power failure/turn off ##THUMP##! You even have a mono sum on the left Lo output.

    As for the \"Powered Speaker Processor\" thing, sales tool perhaps? Whatever the reason, it has all the same crossover and filter types, Yes the wizard is slanted toward powered speakers... but the PX is what I'm currently running on my DJ/KJ rig... I have a pair of custom built tops, with a QSC MX3000 running the tops, and a 2x18\" sub with a Crest 4000 running it...

    As for the mic? VERY useful tool! Why have a processor with this much power without all the tools? EVERY rig gets a Flattening before it goes ANYWHERE! You haven't been to the READ ME FIRST BEFORE POSTING section have you? There you will want to \"start here\"
    http://www.dbxpro.com/Forum/viewforum.php?f=61
    and then go to the FAQ's:
    http://www.dbxpro.com/Forum/viewtopic.php?t=960
    http://www.dbxpro.com/Forum/viewforum.php?f=60
    there you will find a wealth of info... lots on the Auto EQ process..
    http://www.dbxpro.com/Forum/viewtopic.php?t=1330
    http://www.dbxpro.com/Forum/viewtopic.php?t=949

    I got your email and yes, I stand by my recommendations...you are somewhat under powered so be careful.

    We'll be here for your questions...
    G
  • DJCDJC Posts: 8
    many thanks for all your advice gadget, much appreciated.

    i think i might go for the px then, i have read about the thump when you lose power with the pa.

    am i underpowered THAT much? both sides of my amp gives 600 watts @ 4ohms, and my sub is rated the same. my tops would be getting 300 watts each running the pair of them off one side of the amp, but they are rated 400 watts @ 8 ohms. is this dangerous for my system?

    DJC
  • GadgetGadget Posts: 4,915
    You have no headroom on the sub, even worse on the tops...thats all I'm saying... It's not dangerous as long as you understand..NO CLIPPING...
    G
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