There won't be improved sounds in the demo. That does not tell us anything either way for GT6, although I personally think it's unlikely the new sounds will be able to work alongside everything else already in the game, at least on PS3. But then again, PD are technical wizards.
This idea that cars aren't being recorded properly is false. Kaz said they re-did everything for GT4 and always record the cars "under load", which is something that was evident in the promo material for the game whilst in development - I've said this several times, that there was evidence, and Kaz has kindly confirmed it.
Also, that thing about Kaz saying GT5 will have better sounds is false - that was people here saying the demos etc. possibly still contain placeholders (because they were obviously remixed GT2 / 3 / 4 sounds). As it turns out, it was true; all of the PS3 games have had placeholders (it's the same sounds in the GT6 demos as are in GT5).
Oh, and the reason so many cars sound wrong is probably because they've been making the "real" ones according to this completely new scheme of theirs, which they've been working on for years. That means they've been recycling old samples, recognisably so - that's what got me suspicious when Prologue came out, given the quality of the rest of the sound approach (this was also about the time I started fiddling with sound synthesis).
Looking at the progression of the overall approach to sound that PD has made since GT3, it's obvious the direction they're heading in (physical modeling). That some people don't know what that means (or haven't even seen the signs) is irrelevant, and they should perhaps hold their tongues (/ fingers) if they're unable to fathom what it means to
generate sounds in a "completely different way".
If you want a little hint at the kind of thing that they might do (there are so many ways the synthesis could be done; that every other game does it one way does not make it the best way by any stretch), have a look at LFS and what is possible (in terms of the range of expression) with the external tweaker tools and the inbuilt sound editor. Then consider that T10 are looking at the possibility of some kind of "source-filter model" for their sound generation.
swingal
TheBoysTakeMinecraft
How did you tweak it, and what did you change to make it sound / perform like a LFA
Ive adjusted the engine to match parameters of the real engine ... that's all ..
Nobody will claim that LFS's sound is high fidelity, but the fact that you can get so many sounds out of the same "samples" and that the timbre variation is so smooth and accurate throughout the rev range, and the whole system so responsive, should raise questions for other systems.
The key thing to consider, as I've repeated, and as someone else mentioned, is the word "expression": Yamaha's latest instrument synths have great fidelity (sample-based), but also excellent expression (physical modeling driving the control of samples and other synth elements). Ensuring the fidelity of static samples is easy, dynamic expression - in a believable sense - it's what's lacking in engine sounds across the board. Everyone's just too used to standard sample based synths to truly recognise their inherent uncanny nature.