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Drive Rack 260 or PA and Crown Macrotech 36X12

BallroomdancerBallroomdancer Posts: 17
edited November 2007 in Configuration Wizard
1) Drive rack mentions MA 3600 in the presets, not the MA 36X12. How would I wire and setup the Driverack 260 or PA to two MA 36X12s?

Comments

  • DraDra Posts: 3,844
    Hello, I will assume a few things. If I am wrong, correct me.

    You are bi-amping 2 pair of cab's, each with a horn and lo-freq drivers and no subs are used (at least with these amps). \"12\" amp each for horns and \"36\" amp each for woofer(s).

    Cheat method: Select 1202 for Bi-amp Hi and 3600 for Bi-amp Low.
    Test method: Do gain structures and manually set amps per the back of the the manual and on this and the former forum.

    However you decide to go, now simply hook up Hi ouputs to the \"12\" side and Low outputs to 36 side.


    If you need more help, post back.

    Dra
  • DraDra Posts: 3,844
    Sorry, didn't mean to say 2 pair.

    Dra
  • I'm not bi amping at the present time.

    I have 2 Crown MA 36X12s. Each with the following:

    I will use the 3600 side of the crown to power a 2 ohm load consisting of the 3 sets of (EV DH2010A driver in a old EV SH 1502 cabinet and I replace the base with the JBL 2226H 600 watt vented 15 in sub). The passive crossover point is 1,600 HZ. This is similar to the JBL SRX4725 SRX

    The MA36x12 had a MA3600 output for channel 1 (1 ouput for both L and R channel) and a MA1200 output for channel 2 (1 ouput for both L and R channel) .


    Wayne
  • DraDra Posts: 3,844
    Now let me see if I understand. You have 6 EV SH1502 boxes. You replaced the 15\" EV speakers with JBL's. You are running passive. Each 36 side of the 36x12 amps will power 3 cabs in parallel (2.6 ohms). 12 side just sitting there.

    Just tell the wizard that you are using a single 3600 amp. Is that what you needed? You're still better off if you actually set the amp with the gain structure set-up. It may be dead on but you can still clip them if it is not set to the board's clip point.

    Dra
  • You understood correctly.

    Thanks,
  • GadgetGadget Posts: 4,915
    NOT a good idea!... The Mac 3600 in 2 ohm mode is unstable...plus it's a huge power sucking monster in the 2 ohm mode...Yes it can do it, but you better be very careful! It WILL send the cones flaming onto the dance floor if your not careful...
    Gadget
  • Off topic

    2 ohm load is 1800 watts per side
    speakers each side 3 speakers x 600 watts. 15 amps
    Fairly even match.

    I am not a sound eng. What would you recommend?
  • DraDra Posts: 3,844
    Gadget,

    Is it possible to put 2 cabs per 36 side, then \"bridge\" the two 12 sides together for the other 2 cabs.

    Dra
  • As I said in the previous post, I am not a sound eng. How would I bridge the 1200 side? By the way, thanks for your advice.
  • GadgetGadget Posts: 4,915
    well...
    Well, 3600 is capable of a heck of a lot more current draw than you think.. I've seen 30 amps on my mac 3600 @ 4 ohms. 2 ohm loads are iffy for conventional power amps... it's risky because they can draw significant current in the 2 ohm load... remember, thats darn near a complete short...which the Crowns can do.. but for how long? and how hot are they going to run and what is the diminished life expectancy of the amp running balls to the wall all the time? I checked the site and they do say it will do it... I don't know.. I know it wasn't good with my 3600 VZ..

    No you can't bridge amps on different amp chassis...too many variables..
    g
  • DraDra Posts: 3,844
    Gadget, does he have any real options here?

    Ball..., maybe put 2 cabs per 36 and 1 cab per 12 for front / center fills. Or... If you stack them 3 high put the 12 sides on the bottom as to not cut heads off (as bad).

    It's hard to make real recommendations without knowing your needs.

    Invest a few bucks and put them up on Ebay. Somebody may be needing an amp to bi-amp with. Set a minimum price that will allow you turn around and buy 2 amps.

    You are between a rock and a hard place. Good luck.

    Dra
  • Thanks for your input.
  • Gadget wrote:
    NOT a good idea!... The Mac 3600 in 2 ohm mode is unstable...plus it's a huge power sucking monster in the 2 ohm mode...Yes it can do it, but you better be very careful! It WILL send the cones flaming onto the dance floor if your not careful...
    Gadget
    Thanks for your advice. I have since made some changes. I have gone to a 4 ohm load. It has a much cleaner sound.
  • GadgetGadget Posts: 4,915
    There you go lad... much safer too...

    G
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