SPOTLIGHT QQ forum members collaboration on new 5.1 and Atmos mix

[kfbkfb]

Any of those options would sound better than a matrixed mp3.

I was mainly thinking about an easy way to create a stereo mix (5.1 -> 4.0 -> [QS encoded]2.0) for stereo streaming services, stereo earbud listening and (old school) stereo MP3s, I know matrix encoded/decoded surround sound directional accuracy is reduced, but QS encoding would provide options for retrieving some semblance of the surround sound mix and is said to sound more spacious in stereo (sound to the left of L and to the right of R).

Anyway...back to the original topic of this thread...


Kirk Bayne

 

[Zacabeb]

You can create a downmix that is more compatible with modern upmixers/matrix decoders by using the coefficients of 5:2:5 encoding for Dolby Pro Logic II/Dolby Surround Upmixer:

Lt = i(1.000L + 0.707C) + j(0.866Ls + 0.500Rs)
Rt = i(1.000R + 0.707C) - j(0.500Ls + 0.866Rs)

Where i is a phase shift of at least 180º and j is a phase shift 90° lower (phase shifting ensures time coherence and reduces cancellation and comb filtering artifacts.)

LFE can be added as well but needs to be strongly attenuated.

Using the above matrix avoids the 7.7 dB crossfeed of LF and RF into Lt and Rt of QS that collapses the front stage if undecoded or decoded with something not designed for QS, as well as making the surrounds decode with less bleed into the fronts.

 

[Methuselah’s Grandpa]

I posted the "5.1 sampler" earlier but I thought I'd share the samples as DD+ & TrueHD Atmos for any of you who would be interested in hearing them. There are two formats available for the TrueHD Atmos sampler (MKV & M4A), ...the MP4 is eac3-joc (Dolby Digital+ Atmos).

1.

Ummm - Middle Ages (TrueHD Atmos sampler).mkv​

2.

Ummm - Middle Ages (TrueHD Atmos sampler).m4a​

3.

Ummm - Middle Ages (DD+ Atmos sampler).mp4​