Film-Tech Forum ARCHIVE: Spot surround by looking at the soundtrack?

This is topic Spot surround by looking at the soundtrack? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Dan Chilton (Member # 2288) on 11-19-2005, 08:27 PM:

We just installed a new surround EQ card and I want to test it with a trailer loop. Is there a way, by looking at the soundtrack, to find a good scene to test the surrounds with? I'd prefer to use a pink noise card, but I don't have one, unfortunately. I've noticed that some of the trailers have a small dot-dash line along certain points of the soundtrack... is that an indicator of surround?

Posted by Gordon McLeod (Member # 33) on 11-19-2005, 08:29 PM:

Nope the dash line is DTS timecode
Get some surround test film from Dolby

Posted by Dan Chilton (Member # 2288) on 11-19-2005, 08:32 PM:

quote: Gordon McLeod
Get some surround test film from Dolby

Gordon: I'll do that, but in the short-term is there any way to know by looking at the soundtrack?

Posted by Louis Bornwasser (Member # 3063) on 11-19-2005, 08:35 PM:

If you were to reverse (temporarily) ONE of the cell leads, you would have center channel audio coming out of the surrounds. This is an easy test anyone can do. Reverse means take, for example, the LEFT cell pair and reverse the red and black wires.Louis

Posted by Aaron Sisemore (Member # 145) on 11-20-2005, 04:01 AM:

quote: Dan Chilton
I'll do that, but in the short-term is there any way to know by looking at the soundtrack?

Nope.

-Aaron

Posted by Dominic Espinosa (Member # 2122) on 11-20-2005, 05:08 AM:

Turn off/down your amps running the screen chanells and run a trailer for an action movie.
It's not like you can really adjust it properly without test film anyway but you'll know there's something coming out of them at least.

Posted by John Pytlak (Member # 331) on 11-20-2005, 07:35 AM:

Following up on Louis's suggestion, running an old bi-lateral mono track with the phase temporarily reversed on one channel should put most of the sound through the surround speakers.

Can't you borrow some Dolby test film, which is the best option?

Posted by Marin Zorica (Member # 1716) on 11-21-2005, 08:02 AM:

What's the purpose of testing EQ card with trailer or surround test film?

Use pink noise and do eq of surround speakers with test microphone.

Instead of pink noise generator you can generate pink noise on some audio software and burn it on CD so you got pink noise.