[Help] Dolby Surround 2.0 Matrixed files Upmix

[deleted user]

If it's correctly decoded, I think it definitely should yeah. At least in terms of compression. Obviously the dematrixing introduces a form of loss of sorts.

[allldu]

I have another question for the knowledgable people around here.

I have an UHD player, which has a DTS:Neo 6 algorythm built-in, and if I turn it on on a 2.0 pcm, it sends a decoded surround mix to an HDMI out. So if I understand correctly, when I conncet it to an AVR, what I'll have there is a 5.1, yes? Meaning, my AVR will read the signal as a 5.1, and won't do any upmixing on its own?

[zoidberg]

If you sent a decoded multichannel pcm signal to your AVR then yes it should just play it back 'as is' although any DSP processing you may have selected will be applied, as will any bass management. The question is will your UHD player be better at this than your AVR

[allldu]

If you sent a decoded multichannel pcm signal to your AVR then yes it should just play it back 'as is' although any DSP processing you may have selected will be applied, as will any bass management. The question is will your UHD player be better at this than your AVR

Thanks for this! Well, I read on many occasions, the new AVRs with Atmos have a new decoding mode called Dolby Surround, which is the next step for DPL (funny how things go in cirlces - Dolby Surround - DPL - DPLII - DSurround ) , and it is inferior to DPL. It's the same algorythm, sure, but the processing makes it even less authentic than DPL. So if I want both Atmos (for newer movies) and DPL (for golden classics) in one box, it's not gonna happen. On the other hand, DTS: Neo 6 is an alternative to DPL, and if you believe the late Disclord, it does its job even better than DPL. Mid-range Atmos AVR don't have Neo 6 built-in, whereas my UHD player does. So this seems like a reasonable solution to me.

[SpaceBlackKnight]

I've been experimenting with the Foobar FreeSurround and Channel Mixer plugins to attempt upmixing 2.0 tracks into discrete channel 4.0 or 5.1. AFAIK, these use algorithms that are not quite the ones Dolby Pro Logic or DTS Neo 6 use, and WAVs that were made under both plugins in many settings makes some of the back and center channels on my sound extremely tinny or phasey to my my ear.

OTOH, when I play direct 2.0 tracks through my Harmon/Kardon receiver they decode properly in PL II and/or DTS Neo 6 modes.

SpoRv had mentioned a plugin developed for Foobar that had actual DPL II schematics in it, but I cannot find such a thing in any search (probably been eradicated by a DMCA complaint through Dolby). Otherwise, what specific settings would one recommend with using the Foobar FreeSurround and Channel Mixer plugins?

[spoRv]

Well, it seems that we, "poor project makers" have to not only preserve original mixes that is often not available on BD or UHD-BD, but also decode the Dolby Surround properly and release as 4.0 lossless, as new AVR are even worst than old ones to decode them!

[pipefan413]

If you sent a decoded multichannel pcm signal to your AVR then yes it should just play it back 'as is' although any DSP processing you may have selected will be applied, as will any bass management. The question is will your UHD player be better at this than your AVR

Thanks for this! Well, I read on many occasions, the new AVRs with Atmos have a new decoding mode called Dolby Surround, which is the next step for DPL (funny how things go in cirlces - Dolby Surround - DPL - DPLII - DSurround ) , and it is inferior to DPL. It's the same algorythm, sure, but the processing makes it even less authentic than DPL. So if I want both Atmos (for newer movies) and DPL (for golden classics) in one box, it's not gonna happen. On the other hand, DTS: Neo 6 is an alternative to DPL, and if you believe the late Disclord, it does its job even better than DPL. Mid-range Atmos AVR don't have Neo 6 built-in, whereas my UHD player does. So this seems like a reasonable solution to me.

I don't know much about it thus far but supposedly DTS Neural:X is essentially a modification of DTS Neo:6 so hopefully a bit more of a true representation of the decoded Dolby Stereo matrix than the new Atmos-era "Dolby Surround" decoder. My AVR has both but not Neo:6 or DPL.

Of course it's entirely possible that the sort of generational change from Pro Logic IIx to Dolby Surround also happened from DTS Neo:6 to Neural:X meaning it too might be significantly less accurate so I don't know. I've thus far been unable to think of a moment in some film or another that would let me clearly test the modes against each other, and I don't know how to make a matrix-encoded test file that's specifically 4-to-2 channels with mono surround (I only know how to do it using the more recent Pro Logic II mode with separate surround channels).

However, I will say that they deal very differently with mono: Dolby mode divides 1 channel into at least 3, with the high end going to C and low end going to L+R, but DTS appears to send the whole thing to C. In my case that's actually better because my centre speaker has a significantly better bass response than the sides.

[spoRv]

https://hometheaterhifi.com/volume_8_1/d...-2001.html

reading this, it appears Neo:6 is not that great... would like to hear more opinions from our members here, though!

[pipefan413]

https://hometheaterhifi.com/volume_8_1/d...-2001.html

reading this, it appears Neo:6 is not that great... would like to hear more opinions from our members here, though!

I've only ever very briefly tried it but didn't like using it because it was being decoded on the UHD player (and applied to everything, matrixed or not, so I had to keep going into settings to change it). Most likely better to use the DTS Neural:X on my Denon AVR which I can easily flick on or off at the press of a button. However, I'm not entirely sure whether it or the Atmos-generation "Dolby Surround" decoder gives a better representation of the 4-channel Dolby Surround matrix. They both sound pretty similar to me at first glance for a 5.1 or 7.1 track but for mono they perform very differently indeed, with the DTS Neural:X presumably being more accurate but the Dolby Surround arguably being a more impressive sounding option for those with a lot of bass response in their front left and right speakers (mine aren't floor-standing ones so they're not very impressive on that front).

I'm honestly not sure which is more "accurate" for matrixed content (in terms of representing the sound in each speaker as it was intended). It's bugging me but I can't really think of a reliable way to test them against each other, especially given that most of my speakers are just cobbled together from ancient separate setups rather than actually being proper home cinema speakers. It makes it a lot more difficult to determine with clarity what sound is coming from where and whether the levels and frequency response is how it should be. For instance, I would not really be able to tell if I'm getting too much brightness from my rear surround speakers, because they're tinny as hell regardless (my side surround and front left and right ones are a bit better but the back ones are really old satellite speakers.

I'd really like to see a proper comparison of the current Dolby Surround and DTS Neural:X for *specifically* Dolby Stereo 4-to-2 channel matrixed content, but I couldn't really attempt that myself without upgrading almost all of my speakers, which I can't afford right now. From what I can tell, it sounds like DTS Neural:X is a lot more aggressive about extreme directional panning (which is arguably sometimes quite nice but could also be very bad) whereas Dolby Surround is perhaps more sophisticated and indeed less direct about its placement of sounds.

[pipefan413]

If you sent a decoded multichannel pcm signal to your AVR then yes it should just play it back 'as is' although any DSP processing you may have selected will be applied, as will any bass management. The question is will your UHD player be better at this than your AVR

Thanks for this! Well, I read on many occasions, the new AVRs with Atmos have a new decoding mode called Dolby Surround, which is the next step for DPL (funny how things go in cirlces - Dolby Surround - DPL - DPLII - DSurround ) , and it is inferior to DPL. It's the same algorythm, sure, but the processing makes it even less authentic than DPL. So if I want both Atmos (for newer movies) and DPL (for golden classics) in one box, it's not gonna happen. On the other hand, DTS: Neo 6 is an alternative to DPL, and if you believe the late Disclord, it does its job even better than DPL. Mid-range Atmos AVR don't have Neo 6 built-in, whereas my UHD player does. So this seems like a reasonable solution to me.

Re. DTS Neo:6 vs Dolby Surround...

Dolby Surround is significantly more advanced than PLII/x/z. PLII decoders utilized a broadband decoder, which could only steer single sound sources, Dolby Surround now uses a multiband decoder, similar to Neo:6, and is therefore able to steer multiple independent sounds. Dolby surround first takes each pair of channels (front, surround, and rear) and processes them separately.

[...]

DTS: Neural X is said to be a completely new design, independent from Neo: 6/X. There’s not a whole lot of detail on how it works exactly, but it’s said to be a spatial remapping algorithm, which uses the knowledge of the sound position and the speaker locations to properly route sounds to the correct speakers.

(from https://rantingsofamadaudiophile.wordpre...s-neuralx/)

So what I'd seen elsewhere about DTS Neural:X being an evolution of Neo:6 appears to be largely incorrect: if anything, Dolby Surround is closer to it. So no, I would be pretty confident that Neo:6 is not going to be significantly more accurate than Dolby Surround, at least not for the reason you cited (they work in the same sort of manner). As zoidberg hinted, a UHD player with Neo:6 may not necessarily be the best equipment to do the decoding, compared with an AVR running Dolby Surround.

For my own question of whether Dolby Surround (the new version) is more or less suitable to use for stereo content, well... sounds like Neural:X it way off there as well, according to this guy.

Dolby Surround:

With Dolby Surround, it was really difficult to tell the difference between the multichannel mix and the 2ch upmix. The only minor difference being that some sounds originally mixed into the front left and right found their way into the surrounds, most of these being blaster shots or lightsaber noises. DSU impressively preserved the integrity of the original surround mix, objects panning from the front channels to the rear channels in the original surround mix followed almost exactly the same pattern in the upmix. Unlike PLII, there was absolutely no channel bleed whatsoever. With PLII, things like dialogue, which was matrixed to the center, could be faintly heard in the left and right channels, especially when lots was going on. Not so in DSU. The channel separation was so good it might as well have been a discrete mix.

DTS Neural:X on the other hand...

Switching over to Neural X, the first thing that I noticed was a ton of comb filtering and an incoherent sound field. With DSU, each channel carried it’s own separate content with no overlap, with Neural X, it almost seemed as if I had a center channel and two mono surround channels, which fed the front, height, and surround. Unhooking the center channel, I confirmed this to be the case. The separation between the front left, top left, and surround left was nearly non existent, almost as if I were using an old Dolby Prologic decoder with extra speakers attached. Changing the configuration from top middle to front height, rear height, and then 5.1.2 to 5.1, 7.1, and even 4.1 produced the same results. I’m not entirely sure why or what’s going on here, and I intend to do some further testing, but at this point, I would strongly recommend against the use of Neural X for 2ch content.

To be fair, this isn't specifically a 4-to-2 matrix encoded Dolby Stereo / Dolby Surround track he was using (The Force Awakens), so I guess it's entirely possible that it would somehow do better than Dolby for those, which is what I was wondering. But still. Ouch.

Aside: I feel like I need to start calling it something else, because Dolby Surround to me is the original pre-Pro Logic thing. Dolby Surround v2? Dolby Surround mk II? Dolby Surround (Atmos generation)? Dolby Surround With A Vengeance?