Questions Concerning DTS MA 2.0 Mono and Stereo Tracks on Blu-rays (From Labels Like Scream/Kino) and How Older AVRs Process Them (1 Viewer)

[Kaskade1309]

These Onkyo receivers can apply Dolby ProLogic to nearly any 2.0 format - Dolby Digital, Dolby TrueHD, PCM, DTS. The only format that it cannot do this for is DTS-HD MA 2.0.

Correct Josh -- I attempted to explain that in my last post.

For whatever reason, the TX-SR605 doesn't have the processing chops to take a 2.0 mono or stereo signal encoded in DTS-HD Master Audio -- and I have a lot of discs with these types of soundtracks on older titles -- and either steer it into the center (for a 2.0 mono presentation) or matrix it into some kind of pesuedo-surround (for 2.0 stereo presentations).

It only processes DTS-HD Master Audio signals that are in 5.1 or higher, sending the information to the correct speakers.

 

[Kaskade1309]

I've never encountered a "duophonic" (for lack of a better word) mono track on blu-ray. Its always either 2.0 DTS-HD MA with the same single out of left and right creating the phantom center, PCM (which my Yamaha recognizes as stereo) or a lossy Dolby 1.0.

There are a plethora of such "dual mono" titles on the market with these types of audio mixes; I own a lot of them (and on DVD, as well).

Here are some:

Halloween III DVD (Universal; 2.0 mono)
Return of the Living Dead DVD (MGM; 2.0 mono)
Amityville II: The Possession DVD (MGM; 2.0 mono)
Nighthawks Blu-ray (Shout Factory, 2.0 mono)
The Taking of Pelham One Two Three Blu-ray (Kino-Lorber, 2.0 mono)

Nighthawks (which I just watched last night):

Nighthawks Blu-ray (Collector's Edition)

Shout! Factory’s Blu-ray offers the film in very good 1080p HD video quality at the original 1.85:1 theatrical aspect ratio. The print is in fine condition, with excellent detail and texturing, nice contrast, deep shadows, and moderate film grain that’s appropriate to both the period and the subject matter. Colors are strong and accurate, even vibrant when needed (note the bold neon lighting in the disco scene). The audio is available in a solid English 2.0 mono mix in DTS-HD Master Audio format. The sound quality is good, with clear dialogue and excellent mono music fidelity. That’s a plus, given that the score was composed by Keith Emerson from the English prog-rock band Emerson, Lake & Palmer. (It’s also worth noting that the score is intact here for the first time on home video; both The Rolling Stones’ Brown Sugar and Emerson’s Spencer Davis Group cover of I’m a Man play during the club scene. Previous versions replaced these tracks due to music licensing issues.) The mix offers a fairly wide front/center soundstage that works well for the film. English SDH subs are also available.

Taken from:

https://www.blu-ray.com/movies/Nighthawks-Blu-ray/149304/

Audio Format(s): English 2.0 Mono DTS-HD MA

Taken from:

Nighthawks – Collector’s Edition (Blu-ray Review) at Why So Blu?

Here's another example, for the Kino-Lorber Blu-ray of The Taking of Pelham One Two Three:

Audio
English: DTS-HD Master Audio 2.0 Mono (48kHz, 16-bit)

Taken from:

The Taking of Pelham One Two Three Blu-ray

The DTS-HD Master Audio 2.0 mono sound mix does an excellent job of combining the well recorded dialogue, the sound effects, and David Shire’s dynamic score into a solid entity. There are no age-related artifacts like hiss or crackling to distract from the audio track, and one only wishes sound design of the era had routinely given more attention to the aural resonance that such a thriller might have afforded an audience with more advanced sound design.

Taken from:

Blu-ray Review - The Taking of Pelham One Two Three (1974) Blu-ray Review | Home Theater Forum

 

[JoshZ]

Josh,

The issue comes into play when we're talking about 2.0 MONO tracks encoded in DTS-HD Master Audio on Blu-ray Discs -- there is a limitation in my Onkyo's processing that won't allow DTS-HD MA lossless signals that are being bitstreamed to be spread to any other channels than the two fronts (when the signal is two-channel, whether mono or stereo).

This does NOT happen when I watch DVDs with Dolby Digital 2.0 mono or stereo soundtracks -- with THESE, my AVR automatically kicks on Pro Logic II Movie mode and deals with the signal properly. What I am describing is an issue with bitstreaming LOSSLESS DTS-HD MA tracks in 2.0.

OK, got it. So long as you're connected by HDMI, I'd still advise setting your Blu-ray player for PCM and leaving it there. No need to use Bitstream at all in your scenario.

 

[Kaskade1309]

OK, got it. So long as you're connected by HDMI, I'd still advise setting your Blu-ray player for PCM and leaving it there. No need to use Bitstream at all in your scenario.

Thanks; yeah, I am connected via HDMI for everything. I still prefer to have the player send over raw bitstreams for the AVR to decode.

Thanks again for your input.

 

[JoshZ]

Thanks; yeah, I am connected via HDMI for everything. I still prefer to have the player send over raw bitstreams for the AVR to decode.

We all have our preferences and biases, but there isn't much technical reason to use Bitstream output over PCM if you're only decoding to 5.1. The Dolby or DTS compressed signal has to get transcoded to PCM somewhere in the chain regardless. It doesn't really matter whether that happens in the Blu-ray player or in the AVR. They use the same decoders licensed from Dolby and DTS.

Unless your receiver is also one of those models that can't apply Audyssey room correction to PCM. I suppose that's possible.

 

[Kaskade1309]

We all have our preferences and biases, but there isn't much technical reason to use Bitstream output over PCM if you're only decoding to 5.1. The Dolby or DTS compressed signal has to get transcoded to PCM somewhere in the chain regardless. It doesn't really matter whether that happens in the Blu-ray player or in the AVR. They use the same decoders licensed from Dolby and DTS.

Unless your receiver is also one of those models that can't apply Audyssey room correction to PCM. I suppose that's possible.

I understand what you're saying, but whether it's placebo or not, my ears tell me the bitstreaming-to-the-AVR method is preferrable to having the player decode multichannel PCM signals to send to the receiver.

Just a personal preference.

In getting more focused on the topic, is it actually ideal for so-called 2.0 mono soundtracks to be steered to the center channel via some kind of processing like Pro Logic II -- whether it's on Blu-ray or DVD?

When I watch the DVDs I own that contain (Dolby Digital) 2.0 mono tracks, my AVR engages PLII Movie mode and steers the whole thing into the center (for "Dolby Stereo Surround" soundtracks on discs, PLII engages as well, but of course creates that psuedo-surround effect by matrixing the rear channels, etc.) -- now while I don't like the way the whole track is confined to the center position, it does allow dialogue to remain locked to that position, and that is highly preferrable compared to having it come from other speakers, which is the issue I am having now with 2.0 DTS-HD MA tracks...

Right now, when my AVR detects a Dolby Digital 2.0 signal (because I have it set up to do so in the receiver's Listening Mode menu) from a DVD, it will engage Pro Logic II Movie and send a 2.0 mono track to the center while sending a 2.0 stereo track to the appropriate surround areas (keeping dialogue in the center, where it belongs). Is this the proper way to listen to 2.0 mono tracks?

 

[Peter Apruzzese]

I’ve always used ProLogic to decode 2.0 mono tracks for center channel playback. Movie theaters play mono films from the center only. Also use ProLogic to decode 2.0 stereo tracks back to their matrixes Dolby Surround roots. There there are no theatrical films that would be coded to play back in 2.0 in theaters, so you should always engage PL for 2.0 stereo films.

 

[JoshZ]

In getting more focused on the topic, is it actually ideal for so-called 2.0 mono soundtracks to be steered to the center channel via some kind of processing like Pro Logic II -- whether it's on Blu-ray or DVD?

When I watch the DVDs I own that contain (Dolby Digital) 2.0 mono tracks, my AVR engages PLII Movie mode and steers the whole thing into the center (for "Dolby Stereo Surround" soundtracks on discs, PLII engages as well, but of course creates that psuedo-surround effect by matrixing the rear channels, etc.) -- now while I don't like the way the whole track is confined to the center position, it does allow dialogue to remain locked to that position, and that is highly preferrable compared to having it come from other speakers, which is the issue I am having now with 2.0 DTS-HD MA tracks...

Right now, when my AVR detects a Dolby Digital 2.0 signal (because I have it set up to do so in the receiver's Listening Mode menu) from a DVD, it will engage Pro Logic II Movie and send a 2.0 mono track to the center while sending a 2.0 stereo track to the appropriate surround areas (keeping dialogue in the center, where it belongs). Is this the proper way to listen to 2.0 mono tracks?

For a mono film, it is generally better to let Pro Logic II (or another comparable decoder such as DTS Neo:6) collapse the two channels to your center speaker. If played back only through your left and right mains without the center, you rely on those speakers creating a phantom image between them. Phantom imaging really only works well if you're sitting precisely in the sweet spot between the speakers. If you sit anywhere else, this can cause "combing artifacts" where the sound from one speaker reaches you before the other and the entire soundtrack feels weighted toward that side with a subtle sense of an echo following it. It's better to anchor all that sound to just one speaker right in the middle where it's supposed to be.

That said, all of this only works if your center speaker is at least comparable in quality to your left and right. If you put a tiny speaker in the center, you might not get good results from that.

(for "Dolby Stereo Surround" soundtracks on discs, PLII engages as well, but of course creates that psuedo-surround effect by matrixing the rear channels, etc.)

To be clear, a movie soundtrack mixed in 2.0 Dolby Surround (sometimes just called Dolby Stereo or Dolby Stereo Surround) is a genuine surround sound mix that is intended to be decoded to use the rear speakers. It is not fake surround sound. The entire surround mix is folded into two channels by encoding the surround info out of phase with the front soundstage info. This is specifically designed for a matrix decoder to detect the out-of-phase info and steer it to the rear speakers. It is more "correct" to listen to those soundtracks using Dolby Pro Logic II than to listen to them in plain stereo with no matrixing.

Rare exceptions here and there may exist, but in general Pro Logic II will do the right thing for almost any 2.0 movie soundtrack and you should just leave it on when watching movies. The only time you might need to turn it off is when listening to regular music, and even then only if you're a stereo purist who doesn't like music bleed in the rear speakers.

 

[Kaskade1309]

I’ve always used ProLogic to decode 2.0 mono tracks for center channel playback. Movie theaters play mono films from the center only. Also use ProLogic to decode 2.0 stereo tracks back to their matrixes Dolby Surround roots. There there are no theatrical films that would be coded to play back in 2.0 in theaters, so you should always engage PL for 2.0 stereo films.

Thanks Pete.

I definitely use PLII for 2.0 stereo soundtracks, but I was wondering if 2.0 mono should be decoded into the center, as well, which you answered above.

 

[Kaskade1309]

For a mono film, it is generally better to let Pro Logic II (or another comparable decoder such as DTS Neo:6) collapse the two channels to your center speaker. If played back only through your left and right mains without the center, you rely on those speakers creating a phantom image between them. Phantom imaging really only works well if you're sitting precisely in the sweet spot between the speakers. If you sit anywhere else, this can cause "combing artifacts" where the sound from one speaker reaches you before the other and the entire soundtrack feels weighted toward that side with a subtle sense of an echo following it. It's better to anchor all that sound to just one speaker right in the middle where it's supposed to be.

Thank you; this is PRECISELY what I am experiencing right now when I listen to the 2.0 tracks (DTS-HD MA) from the two front channels...results in a weird "combing effect" that doesn't sound right.

That said, all of this only works if your center speaker is at least comparable in quality to your left and right. If you put a tiny speaker in the center, you might not get good results from that.

My center is about as matched as my left/right front mains, being a Polk CSi30 that is mating with RTi12 towers (so it's not a tiny center).

To be clear, a movie soundtrack mixed in 2.0 Dolby Surround (sometimes just called Dolby Stereo or Dolby Stereo Surround) is a genuine surround sound mix that is intended to be decoded to use the rear speakers. It is not fake surround sound. The entire surround mix is folded into two channels by encoding the surround info out of phase with the front soundstage info. This is specifically designed for a matrix decoder to detect the out-of-phase info and steer it to the rear speakers. It is more "correct" to listen to those soundtracks using Dolby Pro Logic II than to listen to them in plain stereo with no matrixing.

Rare exceptions here and there may exist, but in general Pro Logic II will do the right thing for almost any 2.0 movie soundtrack and you should just leave it on when watching movies. The only time you might need to turn it off is when listening to regular music, and even then only if you're a stereo purist who doesn't like music bleed in the rear speakers.

Understood.

So when we upgrade to a new AVR (we're looking at the super-nice Onkyo RZ50, if we can afford it at some point), it SHOULD be able to do what my current model doesn't do now, correct? It should be able to take these 2.0 mono and 2.0 stereo DTS-HD MA tracks and steer them to where they belong?

 

[JoshZ]

So when we upgrade to a new AVR (we're looking at the super-nice Onkyo RZ50, if we can afford it at some point), it SHOULD be able to do what my current model doesn't do now, correct? It should be able to take these 2.0 mono and 2.0 stereo DTS-HD MA tracks and steer them to where they belong?

I would assume so, but honestly I'm suprised to learn that the old Onkyos couldn't do that.

 

[Kaskade1309]

I would assume so, but honestly I'm suprised to learn that the old Onkyos couldn't do that.

Indeed; but it's the truth.

 

[Jesse Skeen]

It’s not about “processing power,” it’s a limit imposed by the receiver’s software. My Pioneer receiver from 2010 had the same problem- it could only play 2-channel DTS-HD tracks in straight stereo, there were no options to apply surround processing. Making matters worse was that my Sony Blu-Ray player didn’t have full internal DTS decoding, so if I used PCM on that I would only get the core DTS track. Seems many players now still don’t have full internal DTS decoding, the giveaway is that they’ll play any DTS 7.1 track as 5.1.

I now have a Marantz receiver from 2017 that lets me apply any surround decoding to any format, I also have an Oppo player with full internal DTS decoding so there are no more issues like this. The Oppo will actually see some discs flagged to output as PCM and some as bitstream- many recent titles are flagged for PCM even when they don’t have any menu sounds or secondary audio so I have to manually switch those to bitstream if they’re in Atmos or DTS:X.

What’s bugged me since the beginning of DVD is why are most mono tracks encoded in 2-channel? Wouldn’t they save some space by encoding them in 1-channel? I imagine some people are probably confused seeing their receivers display “Dolby Surround” and hearing mono also.

 

[Kaskade1309]

It’s not about “processing power,” it’s a limit imposed by the receiver’s software.

Well, isn't that pretty much the same thing? I used "processing power" as a way to describe the AVR's processor's shortcomings.

My Pioneer receiver from 2010 had the same problem- it could only play 2-channel DTS-HD tracks in straight stereo, there were no options to apply surround processing. Making matters worse was that my Sony Blu-Ray player didn’t have full internal DTS decoding, so if I used PCM on that I would only get the core DTS track. Seems many players now still don’t have full internal DTS decoding, the giveaway is that they’ll play any DTS 7.1 track as 5.1.

I now have a Marantz receiver from 2017 that lets me apply any surround decoding to any format, I also have an Oppo player with full internal DTS decoding so there are no more issues like this. The Oppo will actually see some discs flagged to output as PCM and some as bitstream- many recent titles are flagged for PCM even when they don’t have any menu sounds or secondary audio so I have to manually switch those to bitstream if they’re in Atmos or DTS:X.

What’s bugged me since the beginning of DVD is why are most mono tracks encoded in 2-channel? Wouldn’t they save some space by encoding them in 1-channel? I imagine some people are probably confused seeing their receivers display “Dolby Surround” and hearing mono also.

I agree with you, totally, about the 2.0 mono thing -- I never understood this myself. Almost EVERY DVD that came with a mono soundtrack delivered it in two-channel mono, which would then be steered into the center anyway if the user was applying Pro Logic II via a receiver.

We recently picked up the complete DVD series of The Twilight Zone, and every episode here, too, has been mastered as 2.0 mono Dolby Digital...

 

[Jesse Skeen]

“Processing power” would mean the receiver is just technically uncapeable of decoding Pro-Logic from DTS-HD tracks, like it required a more complicated system to do. In this case it certainly COULD decode them, but the operating system is leaving that option out. Like when a DVD locks out buttons during playback.

At least the earlier DTS receivers had a lot of restrictions on the format as opposed to Dolby Digital, such as not letting you use dynamic range compression or fake surround modes. Don’t know if my newer receiver lets you do that as I’ve never had reason to. I think there are some that will only let you use DTS Neo matrix decoding and not Dolby, which would still be better than nothing. Some EX/ES tracks aren’t flagged properly either so manual control of that should be allowed.

 

[Kaskade1309]

“Processing power” would mean the receiver is just technically uncapeable of decoding Pro-Logic from DTS-HD tracks, like it required a more complicated system to do. In this case it certainly COULD decode them, but the operating system is leaving that option out. Like when a DVD locks out buttons during playback.

At least the earlier DTS receivers had a lot of restrictions on the format as opposed to Dolby Digital, such as not letting you use dynamic range compression or fake surround modes. Don’t know if my newer receiver lets you do that as I’ve never had reason to. I think there are some that will only let you use DTS Neo matrix decoding and not Dolby, which would still be better than nothing. Some EX/ES tracks aren’t flagged properly either so manual control of that should be allowed.

Yeah, almost all (that I know of) receivers do not allow "night mode" or dynamic range compression implementations with DTS signals, only Dolby ones, but this is a limitation of the actual codec, I think...

 

[Kaskade1309]

Hello Again Gentlemen.

Just bumping up this thread because I was doing some more thinking on it and, subsequently, performed some additional research by pulling up my TX-SR605's online manual to satisfy a curiosity I had about this 2.0 mono thing...

Firstly, here is what I am at odds with, and perhaps someone could lend some insight about it -- whenever I read a review of a Blu-ray title with a 2.0 soundtrack (usually older catalog films) encoded in DTS-HD Master Audio, there is always a reference, in the audio portion of the review, to a wide soundstage that anchors the dialogue firmly to the center (or some such language). Am I to assume the reviewer is using an up-to-the-minute processor or AVR that allows 2.0 mono tracks in DTS-HD MA to be steered to the center (or, in the case of 2.0 stereo DTS-HD MA tracks, to be matrixed into the surrounds somehow)? If this is so, why would a reviewer mention a "wide front soundstage" that anchors dialogue to the center?

Here's an example of what I mean -- Kino Lorber's Blu-ray release of the original Taking of Pelham One Two Three, which we watched the other night on our own system, has a review done by High Def Digest which suggests this:

The good news for fans of 'The Taking of Pelham One Two Three' is that the English DTS-HD MA 2.0 audio mix has been slightly reworked. This is not the exact same audio track as the previous 2011 release. The 2011 release clocked in between 2.0 and 2.1 Mbps. This 2016 '42nd Anniversary Edition' comes in between 1.7 and 1.8 Mbps. The result is a much more balanced and tonally even presentation. Right out of the gate the opening David Shire score has a lot more power and presence but it has a better balance to it. The powerful bass thunders while the saxophone interludes don't sound so piercing and shrill as they once did. Once the main feature gets running, dialogue maintains its front and center presence as before, but it sounds more organic to the mix. Atmospherics and background sound effects also sound slightly tweaked to give the scenes in question a better sense of space and dimension. Imaging is effective as there is a notable sense of movement to the action, particularly when the train is rushing through the tunnel towards the end of the film. Free of any hiss or pops, this is a notably improved audio mix that easily stands out in side by side comparisons.

In looking at what I highlighted in bold, one would assume a reviewer is talking about a mix encoded for surround with an LFE channel, to boot (referring to the "powerful bass thunders" comment; I don't detect ANY bass in this mix when I play it back) -- but what concerns me more is what he says about the dialogue maintaining its "front and center presence" and the "atmospherics and background sound effects" being tweaked to give a better sense of space and dimension. When I play this back through my Onkyo 605, as I had been describing in this thread, the AVR kicks into Stereo mode and the whole mono track is played through the left and right front channels, which causes the weird combing effect (sometimes I can sense a bit of "center lock" when characters speak, but it's definitely a phantom/placebo thing). I don't really detect any kind of spatial movement or immersive cues as the reviewer seems to be suggesting.

At any rate, I did some research on the listening modes available with my AVR just to be sure I'm truly unable to process 2.0 DTS-HD MA signals in anything other than Stereo, and alas, I was correct -- the only sound modes that can be used when 2.0 DTS-HD MA signals are being sent to the unit are Stereo and Direct, which would yield the same result (the two-channel mix would come from my two front speakers). Of course, this is with bitstreaming the Master Audio signal, not switching my disc player to output PCM (which, as we have discussed here, is an alternative to processing these signals so I can maybe use other sound modes).

See here:

Onkyo TX-SR605 User Manual (Page 65 of 100) | ManualsLib

www.manualslib.com

If I don't want to switch the player to output PCM, is the best way to listen to these two-channel mono and stereo DTS Master Audio soundtracks through the receiver's Stereo mode, as I have been doing? I am just wondering what the reviewers who wrote about this disc (most share the HDD reviewer's sentiments) -- and others with 2.0 DTS MA tracks -- are referring to when they speak about these mixes sounding "center focused" or boasting a broad soundstage and such...I don't hear it when I view BD titles with Master Audio mono or stereo tracks.

Is it to be assumed they're using an upmixing technique in a newer processor that's allowing these tracks to be spread beyond the two front channels? I wish they'd indicate that kind of stuff in reviews...

 

[Peter Apruzzese]

2.0 mono tracks from movies should be played via ProLogic to decode to the center speaker. 2.0 stereo tracks from movies should also be decoded via ProLogic to recreate the original 4 channel matrix sound (L, C, R, mono surround). As far as I know, Pelham is mono. The reviewer might have felt the newer sound transfer is superior to the old.

I would presume most reviewers wouldn’t use any enhancements and would report on the straight audio playback, other thanProLogic decoding as noted above.

 

[Josh Steinberg]

2.0 mono tracks from movies should be played via ProLogic to decode to the center speaker. 2.0 stereo tracks from movies should also be decoded via ProLogic to recreate the original 4 channel matrix sound (L, C, R, mono surround).

This gets back to the original question posed in this thread, which has been asked and answered. Older Onkyo receivers from that era are not capable of properly decoding DTS-HD MA 2.0 audio tracks to anything other that straight two channel left-and-right stereo. There is a quirk in the processing that does not allow ProLogic to be engaged in combination with a DTS-HD MA 2.0 track. The only solution to this, short of buying a newer, more modern receiver, is to turn bitstreaming off on the Blu-ray player, allowing the decoding of the DTS-HD MA 2.0 signal to happen in the player, rather than the receiver. The player will then output a PCM 2.0 signal, which the receiver is able to properly apply ProLogic processing to.

That is the only solution to this issue. Unfortunately, the original poster does not wish to allow his Blu-ray player to decode the audio, and there is no way for that Onkyo to apply ProLogic to DTS-HD MA 2.0 tracks. Every DTS-HD MA 2.0 track that is anything other than straight two channel left and right stereo will not decode properly and will not sound correct when left to the receiver to decode, because the Onkyo receivers of that era cannot apply ProLogic to DTS-HD MA 2.0 tracks.

 

[Kaskade1309]

2.0 mono tracks from movies should be played via ProLogic to decode to the center speaker. 2.0 stereo tracks from movies should also be decoded via ProLogic to recreate the original 4 channel matrix sound (L, C, R, mono surround). As far as I know, Pelham is mono. The reviewer might have felt the newer sound transfer is superior to the old.

I would presume most reviewers wouldn’t use any enhancements and would report on the straight audio playback, other thanProLogic decoding as noted above.

But there is no way for my AVR to take 2.0-channel DTS-HD Master Audio signals and use Pro Logic, as we have been talking about...the only modes available when these types of signals are bitstreamed, per my previous post, are STEREO and DIRECT, both yielding the same result (the 2.0 track from the left/right speakers only).

Yes, The Taking of Pelham One Two Three is in 2.0 DTS-HD Master Audio MONO -- and this plays through my left/right speakers because of the aforementioned limitations of my AVR's processor. I suppose what I am asking is, for a mono track, why do these reviewers find such "wide soundstages" when listening to these mixes? In my system, because I am bitstreaming, the 2.0 mono comes from the left/right channels, so I don't experience anything remotely resembling a wide soundstage...it's basically just the awful combing effect that really lends no directionality.

If I don't wish to switch the player's digital audio output to PCM, is the best way to listen to these tracks the way I am....that is, through the AVR's Stereo mode while getting brief glimpses of a "focused center" if I sit directly in the sweet spot?