Disney's Tarzan (1999) Audio Track

[Turisu]

All DTS discs are 5.0 in that they have no discrete LFE channel. When decoded, the surround channels are high-passed at 80Hz with the reciprocal becoming the LFE channel. So if there were no audio in the surround channels that dipped lower then 80Hz then you could technically have a true 5.0 mix but this is not the case with Tarzan. It does have sub-80Hz audio in the surrounds and this would have been decoded into a discrete LFE channel when exhibited theatrically.

[Doctor M]

All DTS discs are 5.0 in that they have no discrete LFE channel. When decoded, the surround channels are high-passed at 80Hz with the reciprocal becoming the LFE channel. So if there were no audio in the surround channels that dipped lower then 80Hz then you could technically have a true 5.0 mix but this is not the case with Tarzan. It does have sub-80Hz audio in the surrounds and this would have been decoded into a discrete LFE channel when exhibited theatrically.

So are you saying if your audio setup channels low frequencies to the LFE speaker, it's technically being played back correctly? I thought DTS would, by default, low-pass the speakers below 80Hz.

[Turisu]

The LFE channel is comprised of the low frequencies from just the surround channels. But if your set up is sending everything below 80Hz to the sub then I guess the matrixed 5.0 track would sound the same as the discrete 5.1.

That's not to say that this is true of Tarzan's BD 5.0 track though. The original track was mixed in 5.1 and then the LFE channel is matrixed into the surrounds to save space. It could be that the LFE channel isn't even matrixed in to the BD track's surrounds. I haven't compared them directly.

[dvdmike]

Isn't that only true of the DTS version on CD?
The Dolby would be "true" 5.1 would it not?
Mind you it also had an SDDS 8 mix and I think it was too early for ES/EX and treasure planet was the first Disney 6.1 title?

[Turisu]

Yes, that should be the case. Both would be based on the same 5.1 master mix. I've heard tell of theatrical DTS tracks sounding better or worse than the Dolby mix but I don't see why this would be the case as surely there can only be one mix signed off by the sound team and director.

[dvdmike]

While that is kinda true, sometimes they mix for the top and then mix down
SDDS 8 > Ac3 and sometimes the reverse.
Same as now, they mix for Atmos and then downmix for a 5.1 base, or they got for the show format ie. IMAX 12 channel.
In saying that there are differences in mixes like the Star Wars 70mm ones for example

[Doctor M]

I believe the DTS tracks were usually better than Dolby, not because of the format, but because DTS tended to use higher bitrates.