Film-Tech Forum ARCHIVE: QSC USA amps

This is topic QSC USA amps in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Tom Wienholt (Member # 1510) on 04-13-2005, 05:51 PM:

How should the dip switches on the back of a QSC USA900 amp be set? Should the switch be set for a 50Hz or 30Hz cut off? I assume that the screen channels and surrounds should be cut off at 50Hz and subs at 30Hz. Am I correct? Thanks.

Posted by Samuel Hynds (Member # 2610) on 04-14-2005, 12:19 PM:

Hi Tom,
For the Screen Channels (Left, Center & Right) set for a 30Hz cut off. For the Surround channels set for a 50Hz cut off. For the Subwoofer turn the cut off feature OFF - this way you will go down to about 25Hz or so.

Have fun [Wink]

Sam Hynds - Product Specialist, Cinema

Posted by Tom Wienholt (Member # 1510) on 04-14-2005, 05:29 PM:

I don't think that the cut off feature can be turned off. It has to either be set for 30Hz or 50Hz.

Posted by Richard Fowler (Member # 893) on 04-14-2005, 05:40 PM:

Tom,
the switch next to the filter switch ( #4 / #7 ) will turn on and off the filter function.
Sam works for QSC...so he is a product specialist for that company [Cool]

Posted by Antonio Marcheselli (Member # 373) on 04-14-2005, 09:17 PM:

Hi Sam!

Nice to see you!

Does not 50Hz filter adds a little boost on the lowest end before the cut when enabled? Just to check if I correctly understood the DCA manual!

Bye
Antonio

Posted by Samuel Hynds (Member # 2610) on 04-19-2005, 01:24 PM:

Thanks Richard for the kind remarks. [Cool]

Antonio - Yes the DCA with the 50Hz High Pass engaged does boost a little bit, about 1dB very close to the cut off frequency. This is done so you get a little better bass response, while protecting the loudspeaker from low bass signals.

Ciao, Sam

Posted by Antonio Marcheselli (Member # 373) on 04-21-2005, 05:48 AM:

Only 1 dB, nice to know it!

Bye

Antonio