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]

I am running an Onkyo TX-SR605 AVR, which was purchased in and around when the model hit the market (circa 2007 or so), and while we have experienced zero issues with it thus far (save for what may be a now-failing HDMI out port that I use only for checking the receiver's settings on my 4K display and, of course, its lack of Atmos/X support), there is a weird limitation it exhibits with regard to processing certain kinds of bitstreamed audio signals, given that it just doesn't have the horsepower to do so (which makes sense at the unit's price point).

When I view some Blu-rays of older titles, mainly from "boutique" labels like Scream/Shout Factory and Kino Lorber, that have DTS-HD Master Audio 2.0 (two-channel) audio tracks, whether it's in mono or stereo, my AVR can't add processing (such as Pro Logic II) to properly send these tracks where they should go in our 5.1 setup, so the receiver falls back on sending the track to the left and right main channels (which, in our system, are Polk RTi12 towers) in Stereo mode. As you can imagine, this creates all sorts of odd effects with dialogue in films, notably a really annoying "comb filtering" problem if I'm not sitting PRECISELY in the sweet spot between the two front channels.

Now, I understand there is one workaround for this issue, which is to set my Blu-ray player (a Panasonic DP-UB9000) to "PCM" for HDMI audio output when watching these discs, and that this would allow me to use the receiver's post-processing modes to listen to the tracks more properly, as I do with DVDs that have these kinds of soundtracks (with DVDs, Dolby Digital 1.0 mono and 2.0 mono tracks are correctly steered to the center, while 2.0 stereo mixes are matrixed via Pro Logic II Movie mode). But that's not something I want to get into every time I watch one of these titles (switching from bitstream to PCM and then back again); let's put that aside for a moment...

This is only an issue when DTS-HD Master Audio 2.0 signals are bitstreamed to my AVR; it simply doesn't have the processing horsepower to play these back in any other fashion than in Stereo.

Here's what I primarily want to know, as we will eventually replace this AVR when we either get set up for Atmos and DTS:X or the HDMI out fails on us: For those of you who have newer receivers and processors and watch some Blu-rays of older titles with DTS-HD MA 2.0 mono and stereo tracks, how does the AVR process these? Is it like Dolby Digital signals on DVDs, wherein if the receiver gets a 2.0 signal, it sends everything to the center for a mono presentation and adds some kind of matrix processing for stereo presentations?

Right now, when I watch many of my Scream Factory Blu-ray titles that include 2.0 tracks, such as Nighthawks, Ninja III: The Domination and Tales From the Hood (for some reason these didn't offer an alternate 5.1 DTS-HD MA track like most of Scream's releases), or my only Kino Lorber title, the original Taking of Pelham One Two Three, my Onkyo takes these signals and sends them into the left and right main channels, which ends up sounding really weird, and I can't override this unless I do the "PCM output" switch in the player.

How are these DTS-HD Master Audio 2.0 tracks SUPPOSED to play back in a surround setup? I'm assuming the 2.0 mono and 1.0 mono tracks should come only from the center, like with DVDs, but how are the 2.0 stereo tracks supposed to be processed?

If this is the wrong area of the forum to post this query, my apologies; I wasn't sure if it belonged in Receivers/Amps, or in Blu-ray/UHD Media...

 

[Josh Steinberg]

This is specifically a quirk with older Onkyos being unable to decode DTS-HD MA 2.0 into anything other than straight left or right.

Unfortunately the only solution is the one you mentioned: to set your disc player to decode the signal before it gets to your receiver. Your disc player should properly decode it in a way that your receiver will interpret correctly. Generally, mono will play in the center channel only, while 2.0 surround will decode more expansively, which is how that format is designed to work - a 2.0 surround should get you L C R tracks in the front speakers and activity in the surrounds if the movie is mixed that way.

 

[Kaskade1309]

This is specifically a quirk with older Onkyos being unable to decode DTS-HD MA 2.0 into anything other than straight left or right.

Interesting; I never heard of that until now, but it makes sense because these processors (at a certain price point) just didn't have the processing chops to handle this.

Unfortunately the only solution is the one you mentioned: to set your disc player to decode the signal before it gets to your receiver. Your disc player should properly decode it in a way that your receiver will interpret correctly. Generally, mono will play in the center channel only, while 2.0 surround will decode more expansively, which is how that format is designed to work - a 2.0 surround should get you L C R tracks in the front speakers and activity in the surrounds if the movie is mixed that way.

I understand what you're saying regarding the solution, but with MODERN AVRs and processors, how are these two-channel DTS-HD Master Audio signals handled? Do the 2.0 mono tracks go to the center, like with DVDs? And the 2.0 stereo tracks are processed by Pro Logic II or another matrix platform?

 

[Lord Dalek]

This is specifically a quirk with older Onkyos being unable to decode DTS-HD MA 2.0 into anything other than straight left or right.

Unfortunately the only solution is the one you mentioned: to set your disc player to decode the signal before it gets to your receiver. Your disc player should properly decode it in a way that your receiver will interpret correctly. Generally, mono will play in the center channel only, while 2.0 surround will decode more expansively, which is how that format is designed to work - a 2.0 surround should get you L C R tracks in the front speakers and activity in the surrounds if the movie is mixed that way.

This has nothing to do with Onkyos. My Yamaha reads DTS-HD MA 2.0 mono as a stereo track and frankly it sounds better that way as a phantom center instead of colapsing everything into the center with DPL. Same goes with Criterion and their PCM tracks.

Basically what the lesson here is unless the packaging says its a DTS-HD MA 2.0 Surround track (which is basically Dolby Surround cosplaying as DTS), don't futz with it.

 

[Mark-P]

This has nothing to do with Onkyos. My Yamaha reads DTS-HD MA 2.0 mono as a stereo track and frankly it sounds better that way as a phantom center instead of colapsing everything into the center with DPL. Same goes with Criterion and their PCM tracks.

Basically what the lesson here is unless the packaging says its a DTS-HD MA 2.0 Surround track (which is basically Dolby Surround cosplaying as DTS), don't futz with it.

That may be your preference, but there’s no need to tell others what they should do with their own setups.

To answer the original poster’s question, my various receivers have all had the ability to decode DTS-MA 2.0 in either Pro-logic or DTS Neural X, both of which send 2.0 mono to the center channel only.

 

[Kaskade1309]

This has nothing to do with Onkyos. My Yamaha reads DTS-HD MA 2.0 mono as a stereo track and frankly it sounds better that way as a phantom center instead of colapsing everything into the center with DPL. Same goes with Criterion and their PCM tracks.

Basically what the lesson here is unless the packaging says its a DTS-HD MA 2.0 Surround track (which is basically Dolby Surround cosplaying as DTS), don't futz with it.

I never liked the sound of the "phantom center," which is what I am dealing with now as it relates to these Blu-rays with 2.0 mono/stereo tracks in DTS-HD MA...

While center-only mono doesn't excite me, either, when I watch DVDs with 2.0 mono tracks, it just sounds more satisfying when Pro Logic II drops everything into the center channel so at least DIALOGUE is there and "proper."

Anyway, I suppose I am confused with regard to how two-channel STEREO tracks encoded in DTS-HD Master Audio are handled by AVRs that CAN process them properly, being that you brought up "Dolby Surround" -- in the past, with stereo-encoded VHS tapes and DVDs, these were usually Dolby Stereo Surround signals, and they were perfectly handled by Pro Logic II Movie mode in the hardware (I still have a lot of these discs that boast these soundtracks and are decoded via PLII by my receiver). But with 2.0 stereo DTS Master Audio tracks on Blu-rays, how do processors deal with these? Can AVRs be set up, like it was in the DVD era, to automatically sense these and use something like PLII?

 

[Kaskade1309]

That may be your preference, but there’s no need to tell others what they should do with their own setups.

To answer the original poster’s question, my various receivers have all had the ability to decode DTS-MA 2.0 in either Pro-logic or DTS Neural X, both of which send 2.0 mono to the center channel only.

Thanks Mark.

This indeed is getting closer to what I was asking; so these receivers you are referring to were more modern types, with more advanced processing? My AVR goes back to 2007, so that's why I am asking...

To be clear, a more modern (or brand new) AVR WILL be able to be set so that 2.0 stereo and mono DTS-HD MA signals being bitstreamed will be steered correctly? I understand that with 2.0 mono, the signal usually gets routed to the center channel only, but what about 2.0 STEREO DTS-HD MA signals? Are these handled like old DVD two-channel Dolby Digital Surround signals were, kind of "matrixed" by the Pro Logic II system?

 

[Mark-P]

Thanks Mark.

This indeed is getting closer to what I was asking; so these receivers you are referring to were more modern types, with more advanced processing? My AVR goes back to 2007, so that's why I am asking...

To be clear, a more modern (or brand new) AVR WILL be able to be set so that 2.0 stereo and mono DTS-HD MA signals being bitstreamed will be steered correctly? I understand that with 2.0 mono, the signal usually gets routed to the center channel only, but what about 2.0 STEREO DTS-HD MA signals? Are these handled like old DVD two-channel Dolby Digital Surround signals were, kind of "matrixed" by the Pro Logic II system?

Yes, my receivers have been newer models. When you select the matrix mode you want, the receiver will automatically use it whenever it detects 2.0 (any kind including DTS-MA and Dolby TrueHD) and then will automatically flip over to 5.1, 7.1, Atmos, or DTS-X when detecting those signals. So basically modern receivers will do exactly what you want without having to change settings for each type of soundtrack.

 

[Josh Steinberg]

Interesting; I never heard of that until now, but it makes sense because these processors (at a certain price point) just didn't have the processing chops to handle this.

I understand what you're saying regarding the solution, but with MODERN AVRs and processors, how are these two-channel DTS-HD Master Audio signals handled? Do the 2.0 mono tracks go to the center, like with DVDs? And the 2.0 stereo tracks are processed by Pro Logic II or another matrix platform?

Yes, exactly, unless whoever authored the disc specifically set it for 2.0 mono up play out of the left and right channels, which occasionally happens.

 

[Neil S. Bulk]

Now, I understand there is one workaround for this issue, which is to set my Blu-ray player (a Panasonic DP-UB9000) to "PCM" for HDMI audio output when watching these discs, and that this would allow me to use the receiver's post-processing modes to listen to the tracks more properly, as I do with DVDs that have these kinds of soundtracks (with DVDs, Dolby Digital 1.0 mono and 2.0 mono tracks are correctly steered to the center, while 2.0 stereo mixes are matrixed via Pro Logic II Movie mode). But that's not something I want to get into every time I watch one of these titles (switching from bitstream to PCM and then back again); let's put that aside for a moment...

Why not? Decoding into PCM happens in your receiver or your Blu-ray player and should be transparent to the source. Since you don't have Atmos yet, you won't be losing anything and you'll be gaining quite a bit. If it makes your life easier, I would go for it.

 

[Kaskade1309]

Yes, my receivers have been newer models. When you select the matrix mode you want, the receiver will automatically use it whenever it detects 2.0 (any kind including DTS-MA and Dolby TrueHD) and then will automatically flip over to 5.1, 7.1, Atmos, or DTS-X when detecting those signals. So basically modern receivers will do exactly what you want without having to change settings for each type of soundtrack.

Thanks very much for this explanation. Gives me hope for the future....

 

[Kaskade1309]

Yes, exactly, unless whoever authored the disc specifically set it for 2.0 mono up play out of the left and right channels, which occasionally happens.

That is odd -- I haven't experienced that with any DVD I own (in terms of 2.0 mono tracks refusing to be steered to the center via Pro Logic II, et. al.). I own quite a few DVDs with 2.0 mono tracks and they all collapse into the center when PLII Movie mode kicks in...

 

[Kaskade1309]

Why not? Decoding into PCM happens in your receiver or your Blu-ray player and should be transparent to the source. Since you don't have Atmos yet, you won't be losing anything and you'll be gaining quite a bit. If it makes your life easier, I would go for it.

I just don't want to have to dig into the setup menu, switch to PCM and then back to bitstream when the film is over -- just personal preference. I have also found that I prefer -- whether it's placebo or not -- the end result when my AVR collects the bitstreamed package and decodes it rather than having the player decode it (all over HDMI); just a personal choice.

At the end of the day, the issue wasn't really whether I should switch to PCM output when playing these discs -- it had more to do with what new receivers and processors (well, newer than my Onkyo from 07/08) do with these bitstreamed two-channel DTS-HD MA signals and if they are handled properly, wherein they don't need to be played out of my front two main channels only.

 

[Josh Steinberg]

That is odd -- I haven't experienced that with any DVD I own (in terms of 2.0 mono tracks refusing to be steered to the center via Pro Logic II, et. al.). I own quite a few DVDs with 2.0 mono tracks and they all collapse into the center when PLII Movie mode kicks in...

Right, it’s not frequent but there are a few discs where it’s hardcored as separate left and right channels and there’s no way to steer it due to how it was authored to disc - but it’s so rare that it’s not really part of what you were asking about, so my apologies for the detour there

 

[JoshZ]

Every AVR I've ever owned since the introduction of Dolby Digital in the late '90s has been able to apply Dolby ProLogic to a DD2.0 track. Yours must have been a real cheapie model if it can't do that.

You say you don't want to switch back and forth from PCM to Bitstream output in your player. Are you connected by HDMI or a simple S/PDIF cable (either coax or Toslink optical)? If by HDMI, you don't need to switch back and forth. Just leave it as PCM all the time. HDMI is perfectly capable of trasmitting up to 5.1 PCM. (S/PDIF unfortunately is limited to 2.0 PCM.)

 

[Josh Steinberg]

Every AVR I've ever owned since the introduction of Dolby Digital in the late '90s has been able to apply Dolby ProLogic to a DD2.0 track. Yours must have been a real cheapie model if it can't do that.

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.

 

[JohnRice]

Right, it’s not frequent but there are a few discs where it’s hardcored as separate left and right channels and there’s no way to steer it due to how it was authored to disc - but it’s so rare that it’s not really part of what you were asking about, so my apologies for the detour there

I've heard a few "mono" soundtracks like that and what they did was apply some sort of phase trick to create a fake stereo effect. The result is that there is no actual common (mono) audio remaining. It's no longer two identical tracks, so DPL can't extract anything.

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.

No doubt that was a lack of processing power, and/or Onkyo never bothered to update the firmware to give the receiver the ability. I'm pretty sure at that time it required an authorized tech to update firmware, if it was even possible.

 

[Lord Dalek]

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.

 

[Kaskade1309]

Right, it’s not frequent but there are a few discs where it’s hardcored as separate left and right channels and there’s no way to steer it due to how it was authored to disc - but it’s so rare that it’s not really part of what you were asking about, so my apologies for the detour there

No worries; I appreciate all input.

Yeah, I have yet to experience a 2.0 track of any kind that remains locked to the two front channels, save for the titles I am talking about in this thread that are 2.0 DTS-HD MA in nature (it's a limitation of my hardware/AVR).

 

[Kaskade1309]

Every AVR I've ever owned since the introduction of Dolby Digital in the late '90s has been able to apply Dolby ProLogic to a DD2.0 track. Yours must have been a real cheapie model if it can't do that.

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.