More Gentle Giant in 5.1 coming - Free Hand, Interview and The Missing Piece

[JediJoker]

I have 'seen' (waveforms of) some 5.1 mixes where there is considerable frequency content above 'LFE' range in the LFE channel. The question is *why*. The term 'clean mix' in this context is new to me. Subwoofer/.1 channel lowpass filter options typically max out at 125 Hz, and are often set at 80 Hz, and the filters are steep. Why should .1 content -- signal intended to be output by a subwoofer -- contain frequencies much higher than that? Even if it could play them, it would serve to localize the subwoofer, something usually considered undesirable.

I think the excitement here comes from being able to listen to parts in isolation.

 

[sjcorne]

Hi Plan9, in all GG releases so far, a clean mix of the bass and the drums went to the subwoofer channel. Even in the live bonus tracks in Octopus! A real treat for all of us bass players.

The 2019 5.1 of In The Court Of The Crimson King also has a full range LFE channel with the isolated rhythm section.

 

[Plan9]

Hi Plan9, in all GG releases so far, a clean mix of the bass and the drums went to the subwoofer channel. Even in the live bonus tracks in Octopus! A real treat for all of us bass players. But in most if not all of the JT releases the subwoofer channel got the bass and drums cut off at, say, 400 Hz. Can you comment on that since you worked on both projects? Will SW use the same approach for the upcoming GG releases (clean mix in subwoofer channel?).

Hi!
Lossy Dolby/DTS encoding will lowpass filter frequencies in the LFE channel.
Steven prefers to leave the LFE channel unfiltered, so that your system/subwoofer will do the crossover as it pleases.

 

[ssully]

Not consistently....the Fragile 5.1 mix of 'Roundabout' has full range bass and drums in the LFE, but his Tales 5.1 mix of 'Revealing Science of God' and Relayer's 'Gates of Delirium' do not.

Also, I have observed multiple AC3 (Dolby Digital) mixes where the LFE channel contains robust frequency content out to ~800 Hz, falling off quickly after that to 'end' at ~1 kHz. That is a generous lowpass.

 

[Simplepast Presentperfect]

Hi!
Lossy Dolby/DTS encoding will lowpass filter frequencies in the LFE channel.
Steven prefers to leave the LFE channel unfiltered, so that your system/subwoofer will do the crossover as it pleases.

Thanks for the clarification ! If I understood you right, Dolby and DTS would (automatically) cut off higher frequencies, whereas in a LPCM or a MLP stream you would have a choice of not filtering them out? Another question, I noticed that DVD-A with little or no video content can occupy most of both layers, 6 to 8 GB are common. Are the Dolby and DTS streams compressed on the fly from an uncompressed stream? Is this the way it is done? For instance, the DVD-A of Axe Victim by Be-Bop Deluxe has about 6 GB. If I rip the 5.1 96/24 without compression I get a 5,7 Gbyte file, pretty much the same. The compression to DTS would render a 638 MB file, to DD a 186 MB file. I cannot imagine the visuals occupying much space. This could also feed the LPCM 96/24 stereo stream by downmixing.

 

[ssully]

Whether a X.1 LPCM/PCM version has broadband frequency in the LFE (".1") is a choice made by the mixing engineer. The user's own option to adjust the frequency range of the LFE is on top of that (but obviously, if the mix engineer filtered out high frequencies, you can't get them back).

Lossy Dolby Digital and DTS content is compressed during production, and printed that way on the disc. It is *de*compressed on the fly during playback

Regarding size, the Axe Victim DVD contains three copies of the album -- 2 stereo mixes ( PCM or DTS? Or both? I don't know) and 1 surround mix (DTS 96/24, afaik). Are you comparing apples to apples?

Try ripping just the surround mix, using a 'direct demux' option... that will give you the raw (compressed) .dts file (one per track, or if you can, rip them all as one big track). See what size that is.

 

[Simplepast Presentperfect]

Whether a X.1 LPCM/PCM version has broadband frequency in the LFE (".1") is a choice made by the mixing engineer. The user's own option to adjust the frequency range of the LFE is on top of that (but obviously, if the mix engineer filtered out high frequencies, you can't get them back).

Lossy Dolby Digital and DTS content is compressed during production, and printed that way on the disc. It is *de*compressed on the fly during playback

Regarding size, the Axe Victim DVD contains three copies of the album -- 2 stereo mixes ( PCM or DTS? Or both? I don't know) and 1 surround mix (DTS 96/24, afaik). Are you comparing apples to apples?

Try ripping just the surround mix, using a 'direct demux' option... that will give you the raw (compressed) .dts file (one per track, or if you can, rip them all as one big track). See what size that is.

Thank you for the answers, that is what I always assumed until I looked into the data and thought about an alternative explanation.
Here the detail for Axe Victim (by the way, I recommend also all the other 5.1 releases of BBD !):

Contents of the DVD-A: 5.95 GB located in the VIDEO_TS folder.
Analysis with DVD Audio Extractor (note that in DVDAE DTS and AC3 show up as "48 kHz" but rip correctly to 96 kHz wav or flac if "same sample rate as input" is selected).
Title 1 (remix):
LPCM (96/24, 2 Ch) --- 1.91 GB (uncompressed)
DTS (96/24, 6 Ch) --- 0.64 GB (direct demux) -> for some reason DVDAE rips only at 48 kHz (core?)
AC3 (96/24, 6 Ch) --- 0.18 GB (direct demux) -> for some reason DVDAE rips only at 48 kHz (core?)
Title 2 (original flat transfer):
LPCM (96/24, 2 Ch) --- 1.43 GB (uncompressed)

That is only 4.16 GB, what is the rest (1.79 GB)? Even assuming I am not capturing the "extension" deltas to 96 kHz, that cannot be much data.

If I ripped the 5.1 data uncompressed DVDAE calculates 5.74 GB.
You can still throw in the LPCM stereo mixes (3.34 GB), totalling 9.08 GB.

Use MLP for lossless compression, estimate 60%, you get 5.45 GB.
Meaning that you can have all the data in a lossless format, and still have 0.5 GB for visuals and overhead!

Most information regarding DVD-A in Internet is quite old, but I found MLP referenced many times in the original specifications and that is why I thought about it.

 

[humprof]

All in 5.1 or better please.
Atmos?

He confirmed on @Patrick Cleasby's interview today that Free Hand was mixed in 5.1 and Atmos.

 

[MCDave]

Hopefully we'll see it released by summer, if not sooner.

 

[Sal1950]

He confirmed on @Patrick Cleasby's interview today that Free Hand was mixed in 5.1 and Atmos.

Awesome!

 

[jefe1]

Good news.

 

[The Rang]

Hopefully they repress the earlier Blurays while they’re at it. They have become rather scarce

 

[WBP]

great news!

 

[JediJoker]

Hopefully they repress the earlier Blurays while they’re at it. They have become rather scarce

They should have been included in Unburied Treasure. Missed opportunity.

He confirmed on @Patrick Cleasby's interview today that Free Hand was mixed in 5.1 and Atmos.

And hopefully, the quad mix will be included, unadulterated and with channels assigned correctly.

 

[Simplepast Presentperfect]

They should have been included in Unburied Treasure. Missed opportunity.

And hopefully, the quad mix will be included, unadulterated and with channels assigned correctly.

At the very least I would have expected that they reconstruct the "Playing the fool" live album plus bonus tracks as the complete multitracks were available. Instead, just stereo remixes of the 76 shows from the European shows (Munich, Paris, Brussels and Frankfurt if I am not wrong). That and the ridiculous price made me pass on it on the premise that they would have released the 1970 studio album as a stand alone Blu-ray later. Which they haven't yet. With all the multitracks missing from "In a glass house" at the very least we could have had The runaway and Experience in surround from the live shows. Those are my favorite tracks from the album. Hope they will consider remixing Playing the fool in surround at some point. They did release the Octopus Medley from the album in the Octopus blu-ray release, and it sounds great.

 

[humprof]

He confirmed on @Patrick Cleasby's interview today that Free Hand was mixed in 5.1 and Atmos.

And (here's the other shoe): I think this was implied in Patrick's interview, but @kfbkfb just posted a Sound and Vision interview with Mike Mettler where Wilson explicitly says that all three albums will have Atmos mixes. No release dates, but all should be out this year.

(Wilson also says he'd be open to remixing things like Close to the Edge in Atmos if anyone asked him to.)

 

[Simplepast Presentperfect]

And (here's the other shoe): I think this was implied in Patrick's interview, but @kfbkfb just posted a Sound and Vision interview with Mike Mettler where Wilson explicitly says that all three albums will have Atmos mixes. No release dates, but all should be out this year.

(Wilson also says he'd be open to remixing things like Close to the Edge in Atmos if anyone asked him to.)

This means essencially that there will be 8 channels (7.1), right?

 

[DaverJ]

This means essencially that there will be 8 channels (7.1), right?

I believe most Atmos mixes for home use are usually 12 channels (7.1.4), and the listener's AVR mixes those to the setup's available channels - in my case, 8 (5.1.2).

 

[MCDave]

Actually Atmos isn't mixed for "channels" in the traditional sense. It is object-based, so sounds are assigned to a location rather than a channel. Here's a good, brief explanation from a CNET article:

"Atmos, for the most part, doesn't use channels. Instead, most sounds are treated as "objects." Instead of assigning a sound to a channel (and by extension, a speaker), Atmos lets filmmakers assign a sound to a place. Not "left surround speaker" but "left rear corner." Not "pan from left surround speaker to right sound speaker" but "pan smoothly across the rear wall." Not only does this give greater flexibility, but it improves the experience in the theater and, potentially, at home. "

So, the channel assignment in your system will be done by the decoder in your processor or AVR, based on the direction from which each sound should come and how many speakers (channels) your system has.

 

[Simplepast Presentperfect]

Actually Atmos isn't mixed for "channels" in the traditional sense. It is object-based, so sounds are assigned to a location rather than a channel. Here's a good, brief explanation from a CNET article:

"Atmos, for the most part, doesn't use channels. Instead, most sounds are treated as "objects." Instead of assigning a sound to a channel (and by extension, a speaker), Atmos lets filmmakers assign a sound to a place. Not "left surround speaker" but "left rear corner." Not "pan from left surround speaker to right sound speaker" but "pan smoothly across the rear wall." Not only does this give greater flexibility, but it improves the experience in the theater and, potentially, at home. "

So, the channel assignment in your system will be done by the decoder in your processor or AVR, based on the direction from which each sound should come and how many speakers (channels) your system has.

Thanks for the answer. So, when I rip it with DVD audio extractor, how many channels will show up and decode?