Dolby Warble tone?? Anyone?

[Boom Chic]

Delivery specs for a project asked for Dolby Warble tone. What is this, how can I generate it, and what the heck is it used for?

Thanks.

[The Chinese]

Dolny Warble tone means a Dolby "A" type noise reduction is being used. It is a 1khz tone that "Warbles a bit" However, I suspect that your client may mean Dolby SR...
You might want to check with your client. As for creation, any Dolby 361 or 363 w/ a Dolby A card will create it

[Boom Chic]

I am going totally digital, is this necessary?

[zoundsabar]

The key thing about the Dolby "warble" tone is that it is at "Dolby Level" which is 50% modulation of the optical track area, if my memory serves me right. It is the equivalent of X (can't remember) dB below max level so that when the optical track is exposed it doesn't go into horrible overload distortion or "clash". Check with Dolby's web site to ensure correct level. The actual warble is optional, but the level is critical.

[Tiago Silva]

If the producer is going to make exhibition copies in film, you're never going to be completely digital. Even if you're making a DTS mix, I believe no producer will print a DTS only copy. They'll always make a Dolby SR-D copy and then add the timecode track for DTS.

And Dolby SR-D, like the name implies, always has the Dolby Digital data between the perfs and also the analog optical tracks, for compatibility of the copy with the largest number of theatres possible, and to prevent sound dropouts in case the digital information is obliterated. In the latter case, the decoder will 'panic switch' into the analog Dolby SR track.