DCM-30 odd behaviour

Moderators: Cameron Shoffner, Christian Cook, Kirk Fyvie, Martin Barbour, Fred Thomke, Gary Evans_QSC

Thu Nov 06, 2008 6:00 am

  • Setting up a DCM-30 with SC-434 screen speakers triamped.
    Suddenly the centre channel mid bumped up about 18db. All amp gains set to full.
    Is this a known issue? I have little time to fiddle, show is in 4 hours.
    Also, 8 screens with DCM-30 or -10, not one has any amp monitor audio signal. I don't see any tricks to get it working. All QCS DCM amps and QSC dataport cables.
    DW Macaulay
    Posts: 2
    Joined: Thu Nov 06, 2008 5:56 am

Thu Nov 06, 2008 10:31 am

  • Hello,

    Although the latest firmware addresses some quirks found in previous firmware versions, additional output gain (with respect to the DCM itself) happening suddenly isn’t one of them. I would still use the latest firmware, which can be attained, by using the latest software release DCM Manager 2007 version 1.10.007.

    The sudden bump in gain would tend to suggest a physical wiring/connection being loose or not terminated correctly.

    Troubleshooting the amplifier monitor issue could be better served with a phone call to the factory if possible. Please call 1-800-772-2834 if you are calling from the U.S. Ask for Sam Hynds – Cinema Product Specialist or me (Brad). There are diagnostics within DCM Manager that might help you as well.

    Also something to mention (for others who might come across this post – not the case here) is that QSC sourced DataPort cabling is highly recommended when using QSC DataPort equipped products. We find unnecessary problems/failures with installs that use non QSC DataPort cabling. The cables look like VGA cables common in the computer industry but are not necessarily the same product.
    Brad Sambrano
    Systems Support Engineer
    QSC Audio Products, LLC
    Brad Sambrano
    QSC Audio Products
    Posts: 198
    Joined: Thu Mar 06, 2003 2:01 am
    Location: Costa Mesa, CA

Sat Nov 08, 2008 11:04 am

  • Well, that cinema is pretty much stuck with the centre mid gain set down a LOT. I was actually listening to the channel when it went weird. The D2 display zoomed up across the mid range and the sound got much much (much!) louder. It's in Latvia and I'm back in Canada. I don't think wiring can be an issue, though. I checked the dataport cable by subbing in another one, no change. Possibly the amp has a problem, but why would one channel suddenly find that much more gain? All three screen channels are wired identically and the other two act normally.
    I realize phoning would be better but Latvia is quite a few hours ahead of the USA and this problem appeared at a bad time. Because of construction side problems we were forced to try and do audio setup the morning of the opening.
    Anyway... If anyone has any ideas on how to get amp monitor sound to appear in the monitor, I'm interested in finding out how. We are using all QSC dataport cables, no VGA stuff. All QSC DCA amps, 1222, 1622, 1824, and 3022. DCM-10 and DCM-30 monitor/eq units. Dolby CP650 processors using analog outs. Amp status monitoring works, I had a few output faults. No system (out of eight there) has any amp monitor sound. This seems like just some detail I'm missing but I can't find anything in the manual. There's an attenuation function in the DCM and all are at "0", but there's just attenuation not any gain so that's not the issue.
    DW Macaulay
    Posts: 2
    Joined: Thu Nov 06, 2008 5:56 am

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