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Crazy Config Question...

Cory CooperCory Cooper Posts: 51
edited March 2007 in PA Connectivity
Hi All,

I have a strange gig to do on Saturday for 40-50 people. It's a small room, and I can only fit half my speakers in the area I have to work with. I much prefer to have a sub with me. So, my question is this:

Can I use my current DRPA config and use only one top and one sub with a single amp?

MP 24z Mixer
-Setup for mono output

-Setup as a 1X4
-Output Left High to left channel of amp
-Output Left Low to right channel of amp

CE 4000
-Input Left High from DRPA to Channel 1
-Input Left Low from DRPA to Channel 2

MP 415 Full Range (8 ohm)
-Connect output of amp Channel 1

MP 418S Sub (4 ohm)
-Connect output of amp Channel 2

Will the amp run one channel at 8 ohms and the other at 4 ohms without any problems? Output volume doesn't have to rock the place...mainly for background music and some announcements.

I know, weird huh? Thought...comments?




  • DraDra Posts: 3,844
    For backgroung music and announcements, dump the sub and go 2 x 2 with the M415's. Better chance of even sound dispersion and you won't have to be nearly as loud (perceived). As far as the uneven load on the amp... I've heard they don't like it, but Crown (at least used to) makes Macrotechs that were 1 half MT2400 and 1 half MT600 for bi-amping cabinets. Horns are usually 8 or 16 ohm and the lows (single or double) would be 4 or 8 ohm. That's a potential of 16 / 4. So the answer is... I dunno for sure, but I'd do it if I needed to. But, like I said, you don't need to. I know you want that big bottom end. They'll never know.

  • Thanks DRA.

    I considered simply running the pair of 415s, but dispersion would be the same as a single, due to not having the ability to separate them and run them on stands...I would have to stack them sitting on the floor. A pole-mounted 415 on a 418S would be a perfect fit. Loud volume is not required.
    Crown FAQ wrote:
    Can I run one channel of my Crown amplifier at a different impedance than the other channel?

    Yes. All dual channel Crown amplifiers can be treated as if they are two separate "mono" amplifiers (One channel completely independent of the other)

    In this case it would be 8 ohm on channel 1 (415) and 4 ohm on channel 2 (418S). I guess that answers the amp/impedance issue.

    Was just curious if there is a better way of running a single top/sub, or if anything in my config could damage the gear.

    Thanks again,

  • DraDra Posts: 3,844
    Your right, \"Strange\".
    If your mixer has a mono out or if you Y in to left on all channels and then out of left, then you wouldn't have to change anything in the PA and just use your regular program, but use left side only in PA.

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