Film-Tech Forum ARCHIVE: CP650 public address

This is topic CP650 public address in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Anhtu Vu (Member # 7689) on 08-15-2013, 06:34 PM:

I just installed a CP650/DMA8+ with a new QSC speaker's system in our cinema room. Everything works and sounds pretty good so far and i have not even calibrated the QSC yet.

Does anyone knows if the public address on the CP650 has automatic limiter preset in the chain. It seems like it has very little headroom.

Posted by Jim Cassedy (Member # 4115) on 08-15-2013, 09:40 PM:

I don't think the CP-650 has any type of processing on the microphone input.
I've always used an external limiter & feedback filter.

Is it possible you're over-driving the input?

I know you can set the non-sync input levels on the set-up menu, but I don't
recall there being any way to adjust the microphone input level. (but I could be wrong)

Posted by Louis Bornwasser (Member # 3063) on 08-15-2013, 09:54 PM:

Might also have the phantom power on.

Posted by Carsten Kurz (Member # 5396) on 08-16-2013, 02:47 AM:

quote: Anhtu Vu
Does anyone knows if the public address on the CP650 has automatic limiter preset in the chain. It seems like it has very little headroom.

What did you connect to it and how?

- Carsten

Posted by Steve Guttag (Member # 268) on 08-16-2013, 12:05 PM:

I believe you'll find that the MIC input on the CP650 is one of the few places left where one needs a tweaky tool (flip down the front panel). Other than level, there is no processing in the CP650.

Posted by Tony Bandiera Jr (Member # 2365) on 08-16-2013, 12:12 PM:

Carsten asked a critical question: What is connected to it and how?

You MUST connect a microphone with balanced inputs (XLR) or a mic with a matching transformer.

DO NOT connect any mixers, preamps or other signal processing to that input.

Also, you cannot use the rear panel XLR and the front panel DB9 "Mic Mux" connectors at the same time.

Finally, if the sound is "tinny", lacking bass and dynamic range, you may have a bad mic cable with one line open.