Film-Tech Forum ARCHIVE: Low end audio problems in Digital

This is topic Low end audio problems in Digital in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Tom Maguire (Member # 5314) on 11-02-2009, 02:11 PM:

We've started having some horrible bass distortion problems when running in Digital. Analog is fine. Any suggestions before we call our techs out? Full specs available if needed.

Posted by Steve Guttag (Member # 268) on 11-02-2009, 02:19 PM:

Snappy answer: Run in Analog then!

Longer Answer: Please specify the equipment you are using and when this distortion occurs...what channels? Could you have a bad LF driver in the stage channels or subwoofer(s) that is driven harder in digital? Does the "distortion" exist in the booth monitor as well as in the theatre?....the questions go on and on and on...

Steve

Posted by Tom Maguire (Member # 5314) on 11-02-2009, 02:28 PM:

Yep, running in Analog for the time being. I'll post specs when I get to the theater, can't remember everything exactly off the top of my head.

Posted by Tom Maguire (Member # 5314) on 11-02-2009, 04:21 PM:

We have the following Dolby Equipment:

699 Sound Head
CP-200
DA20 Sound Processor
630 Exciter Lamp Supply for Digital Sound
SA10

Also:
3 QSC Digital Amps

The QSC Amps have LEDs for "Bridge" and "Parallel," one of the amps is not indicating either setting while the other two indicate Parallel.

Posted by Marco Giustini (Member # 4544) on 11-02-2009, 06:24 PM:

3 "qsc digital amps".

I hope they're 4 channels amps because with 3 stereo amps - 2 of them with parallel inputs - you cannot have a 5.1 sound system - don't even mention an EX sound system since you have the SA10.

Knowing the dimension of the room and speakers installed (number and type) would help. The model of the "digital amps" would help too.

Marco