Genuine surround sound in Japanese DBZ movie 13, the 10th anniversary movie, and the BLT dub of DB 1-13

[Zestanor]

Occam's razor dictates the simplest answer is often the truth, since it requires the fewest uncertain assumptions. In this case, I'd argue it's far simpler to assume they mixed Z basically everything from Z movie 3 onwards in stereo in case they want to use that music in stereo for any purpose in future.

Occam's razor is of course merely a mental exercise, since there is no particular reason it should be that the simplest answer is the most likely, or even that the "simplest answer" is a valid category... But let's indulge.

However, even if your theory that they only mixed stuff in stereo that they thought would go on a CD was true, your timeframe is wrong; DBZ Ongakushu vol. 2 contains a nearly* complete soundtrack to DBZ movie 10 in stereo, and vol. 3 was a complete soundtrack to DBZ movie 11 in stereo. So, they were doing the movies' music fully in stereo from AT LEAST as early as Z movie 10... Unless Z movie 12 was singled out for no reason?... And we know from the cassette release of Z movie 6 that they had the full score for that in full stereo, too.

*One track on the Z movie 10 soundtrack was accidentally switched for another, entirely different track from DBZ movie 8, which isn't available on any other release (however it is in stereo here ).

So, again invoking Occam's razor... Is it simpler to assume they mixed pretty much all the music from Z movie 3 onwards in stereo (which isn't particularly harder than mono mixing when you have the facilities to do either), or that they specifically singled out tracks BEFORE MIXING THEM, which were then chosen to go on the CDs, and set aside to specifically mix in stereo, and also mixed a bunch of other random tracks in stereo which wouldn't see a release until as much as ten years later? (I'm fairly certain a bunch of DBZ music wasn't released in stereo until the DBZ BGM Collection CD in about 2006, and we have stuff like that Z movie 8 track which wasn't released on anything until the Z movie 10 soundtrack mistakenly used it)

Yeah I don't think this is conclusive either way. However I'll concede that the later in the game it gets, the more likely a stereo mix for all tracks is likely. At least for DB (not Z), which I've had a lot of experience with because of my ripping project, I think the only things mixed in stereo were the tracks for the 1986 LP that was basically a hype record for the new anime. Everything else was mono. Mixdowns do not seem likely. That's an awfully unprofessional practice.

[Robo4900]

Occam's razor is of course merely a mental exercise, since there is no particular reason it should be that the simplest answer is the most likely, or even that the "simplest answer" is a valid category... But let's indulge.

Well, indeed.
Personally, I think it is logical to minimise arbitrary assumptions, which is the appeal of occam's razor. But still, to each their own.

Yeah I don't think this is conclusive either way. However I'll concede that the later in the game it gets, the more likely a stereo mix for all tracks is likely. At least for DB (not Z), which I've had a lot of experience with because of my ripping project, I think the only things mixed in stereo were the tracks for the 1986 LP that was basically a hype record for the new anime. Everything else was mono. Mixdowns do not seem likely. That's an awfully unprofessional practice.

That's fair. Realistically, Toei & Columbia back in the day did a lot of weird things, so the "Z" era having wildly inconsistent music mixing. Having talked it over with a friend who knows about this stuff, Z movie 3's music was definitely stereo, 4 and 5 were definitely all mono, 6 was definitely all stereo, as were 10 and 11... Personally, I would guess that when the Z movie sessions were being done, they did each movie either all mono or all stereo, and that does appear to be the pattern, so... By this logic, everything from Z movie 6 onwards would appear to be stereo. But this is Toei & Columbia working on Dragon Ball, so it's possible they only did some stereo for Z movies 7-9, though it's hard to tell.

The 12 tracks for the 1986 LP being specifically done in stereo does make a lot of sense, really; given how incredibly early in the game it was, they probably could have sat in on the recording sessions and picked the cues they wanted for the LP, and had those mixed in stereo, already knowing from the outset that they needed X amount of music for the BGM LP. Makes sense. But we got no BGM releases for a long while after that, so there was no need to do stereo mixing again until we're in the Z era... Though I'm not sure why Z movie 3's score appears to have been in stereo, especially since the two after it were only mono.

This is all very weird, and I think it's one of the many Dragon Ball-related things that only gets more confusing as you look into it.