Why 24 bit audio and anything over 48k is not only worthless, but bad for music.

[71 dB]

Why not? I have no dog in this race, except my amendable opinion.

Why not what? My only dog in this race is the truth.

I have an album that sounds better to me in 24/44 than in 16/44. The problem is that it's with different sources.

So it is the source, not the bit depth. If that 24/44.1 version is converted properly (using proper dithering) to 16 bit it will sound just as good. The accuracy of the sound isn't affected one bit (pun intended), only the background noise gets higher, but is still well below audibility in any reasonable listening scenario. Hans himself admits 14 bits (or even 12!) is enough. I say 13 bits is enough for consumer audio. 24 bit is for music production where dynamic headroom is beneficial.

I'll be getting a new DAC any day now, and then I'll run the two different files through the same DAC, Amp and headphones to better compare.

Okay, but if they are different mixes all you will hear is different mixes...

 

[Joe Bloggs]

Just to clarify, Dolby Stereo is a two channel track which when decoded throws all of the info common to both channels to the center speaker, subtracting it from the left and right. Then it adds a rear channel which is inverse phase to the front. On decoding, all out of phase sound goes to the rear two speakers. Almost all movies during that time were released this way. Only the blockbusters had six track mixes. So with Indiana Jones, it might not make a difference, but with The Changeling which was never in six track, it makes a big difference.

I don’t think a lot of these were archived as four tracks. And the stems survive sometimes, so they can create a totally new surround mix. That can either be better or worse depending on the quality of the engineering. But if you want to hear the original surround mix, the only place it survives often is in the two channel Dolby Stereo track. It’s like The Beatles… there are new mixes, but if you want to hear the ones The Beatles themselves did, it’s the mono box.

As far as I can tell Dolby Stereo is just plain old stereo mastered with a view to being surround upmixed by a particular algorithm of its time. I would be interested to hear what you think of it upmixed through the algorithm I've settled on for the past few years . Firstly, which is the particular version of this album where this original Dolby Stereo exists?

 

[bigshot]

Again, I’m not saying it’s important to have Dolby Stereo decoding for big pictures like Star is Born or Star Wars. I’m saying it’s an important alternative for the thousands of smaller movies released in that format where the elements might not survive to make a proper 5.1 remix. It’s clear that the stems no longer exist for Sign o The Times and the 5.1 remix on The Changeling is vastly inferior to the original. These are just two examples, but there are a lot more films where the Dolby Stereo four channel surround mix done for the original theatrical release is better than the recent 5.1 remix for home video. The threads on the home video forums have lots more examples. There are also examples of TV shows released in Dolby Stereo that haven’t been released in multichannel on home video. But if you engage the Dolby pro Logic DSP, you can hear them in surround.

I think it’s important to be able to decode that original format, not just slap processing over the top without properly decoding it first. They had a lot more time and budget to mix films for first release than home video companies do for Blu-ray release. It shouldn’t be surprising that sometimes the original mix is better than the new one.

 

[Joe Bloggs]

Again, I’m not saying it’s important to have Dolby Stereo decoding for big pictures like Star is Born or Star Wars. I’m saying it’s an important alternative for the thousands of smaller movies released in that format where the elements might not survive to make a proper 5.1 remix. It’s clear that the stems no longer exist for Sign o The Times and the 5.1 remix on The Changeling is vastly inferior to the original. These are just two examples, but there are a lot more films where the Dolby Stereo four channel surround mix done for the original theatrical release is better than the recent 5.1 remix for home video. The threads on the home video forums have lots more examples. There are also examples of TV shows released in Dolby Stereo that haven’t been released in multichannel on home video. But if you engage the Dolby pro Logic DSP, you can hear them in surround.

I think it’s important to be able to decode that original format, not just slap processing over the top without properly decoding it first. They had a lot more time and budget to mix films for first release than home video companies do for Blu-ray release. It shouldn’t be surprising that sometimes the original mix is better than the new one.

Do you listen to stereo music through surround or stereo?

 

[bigshot]

which is the particular version of this album where this original Dolby Stereo exists?

I posted a link to CDs that are encoded in Dolby Surround above. Most are out of print, but you can easily find used copies for cheap. Pick up a few of those. They’ll give you plenty to experiment with.

 

[bigshot]

Do you listen to stereo music through surround or stereo?

That depends on the recording. Some mixes are better in the new 5.1 remixes, some are better with the original release stereo mix, a few that were encoded for it are better in matrixed surround, and some are better in my AVR’s DSP that upmixes stereo to 5.1. There are even some really dry recordings that I apply a hall ambience DSP to give them a little depth that the recording is lacking. There are even some things that are better in mono. No one size fits all.

 

[Joe Bloggs]

Again, I’m not saying it’s important to have Dolby Stereo decoding for big pictures like Star is Born or Star Wars. I’m saying it’s an important alternative for the thousands of smaller movies released in that format where the elements might not survive to make a proper 5.1 remix. It’s clear that the stems no longer exist for Sign o The Times and the 5.1 remix on The Changeling is vastly inferior to the original. These are just two examples, but there are a lot more films where the Dolby Stereo four channel surround mix done for the original theatrical release is better than the recent 5.1 remix for home video. The threads on the home video forums have lots more examples. There are also examples of TV shows released in Dolby Stereo that haven’t been released in multichannel on home video. But if you engage the Dolby pro Logic DSP, you can hear them in surround.

I think it’s important to be able to decode that original format, not just slap processing over the top without properly decoding it first. They had a lot more time and budget to mix films for first release than home video companies do for Blu-ray release. It shouldn’t be surprising that sometimes the original mix is better than the new one.

what I mean is that from what I understand of Dolby Stereo, you can't really "encode" or "decode" for it in the sense that it is usually understood today. As noted by others, engaging the Pro Logic decode "decodes" everything, not just Dolby Stereo "encoded" material. There's no way for Dolby Stereo to identify itself as something special for the "decoder" to focus on, and that's because it isn't: the decoder does what it does to all comers, and Dolby Stereo probably just stands for mixes where the engineers had actually listened to the upmix and found it good and/or applied particular tweaks to make it sound better through that upmixer at the time.

 

[Joe Bloggs]

Pro Logic II automatically decodes the old Dolby Stereo into the four channels and Pro Logic II into 5.1. It doesn't add anything else to the old Dolby Stereo. I have both decoders on my Yamaha, but there isn't any difference playing Dolby Stereo through both. I'm curious if Dolby Surround just intelligently applies the decoding depending on the signal, knowing whether it should be 4 channels or more. It would be fine if it just spread the same four channels over more speakers, but it wouldn't be good if it is performing additional processing, like splitting off bits of channels for the additional speakers or adding phase and reverb tricks that aren't part of the original mix. It's easy to check for that by just playing a Dolby Stereo encoded track with Dolby Surround activated and stand in the rear of the room. All the sound you hear coming from the rear should be the same, not divided into left or right or Atmos elevation.

I suspect that they just put it all in one button and it figures out what the intended codec to use based on the signal. It probably still decodes Dolby Stereo, Pro Logic and Pro Logic II, it just doesn't tell you which one it's using.

I've gotten into the habit of checking the old Dolby formats with movies from 1975 to 2000. Often the Dolby Stereo encoding is intact and is better mixed than the modern 5.1 mixes. Maybe selecting the stereo track and engaging Dolby Surround will give you the same result.

One other thing I've noticed is that some music albums, beginning in the mid to late 80s, seem to be mixed for Dolby Stereo. Engaging the DSP puts the vocals in the middle and adds effects in the rear channel. It makes no difference for other albums. There were albums that were specifically released as being in Dolby Surround (Tomita in particular) that were re-released on CD without the Dolby logo, but the master is clearly encoded in Dolby Surround. These are encoded identically to the Dolby Stereo movie format. http://www.surrounddiscography.com/dolby/dolby.htm

By the way, I highly recommend the Charles Gerhart / National Philharmonic classic film scores CDs. They sound great in surround.

I don't see Sign O the Times listed here?

 

[bigshot]

Pro Logic is the decoder being used back then. It’s the first iteration of Dolby Surround. Pro Logic II adds left and right to the rears and a sub channel for things encoded in Pro Logic II. I think Pro Logic II is backwards compatible. From what Daverose says, it appears that the new Dolby Surround DSP isn’t. And yes, you’re right, there’s no flag to indicate the type of encoding.

 

[bigshot]

I don't see Sign O the Times listed here?

That is a movie. Almost all movies during the 80s and 90s had Dolby Surround audio. Big films had more elaborate multichannel tracks as well. Dolby Stereo was the bread and butter surround format that just about any theater could decode. Larger theaters had six track sound, which is more like 5.1.

Back in the day, the poster would have a little Dolby Stereo logo if it was being shown with matrixed surround. If the soundtrack hasn’t been remastered too much, the stereo track on home video release will still decode to matrixed surround.

In a nutshell, Pro Logic uses phase cancellation to isolate the material in the mix that is pure mono and sends it to the center channel. This is always dialogue/vocals. Then it throws all the out of phase content to the rear channels. I’ve never been able to figure out if it subtracts the mono from the front left and right. Maybe Gregorio knows that. It’s a pretty basic encoder/decoder, but it was used for over twenty years and it works pretty well, albeit with considerable spill over from channel to channel.

 

[Elegiac]

Why not what? My only dog in this race is the truth.


So it is the source, not the bit depth. If that 24/44.1 version is converted properly (using proper dithering) to 16 bit it will sound just as good. The accuracy of the sound isn't affected one bit (pun intended), only the background noise gets higher, but is still well below audibility in any reasonable listening scenario. Hans himself admits 14 bits (or even 12!) is enough. I say 13 bits is enough for consumer audio. 24 bit is for music production where dynamic headroom is beneficial.


Okay, but if they are different mixes all you will hear is different mixes...

Why not the DAC thing. About only higher-end DAC's and the oversampling.

Hmm. I'm not sure about different mixes. They should be the same mix. One on CD, and the other a FLAC file.
I won't be surprised if they sound the same, or different. Either way. Curious to see whether the CD is more condensed, as I hear it.

 

[Joe Bloggs]

Why not the DAC thing. About only higher-end DAC's and the oversampling.

Hmm. I'm not sure about different mixes. They should be the same mix. One on CD, and the other a FLAC file.
I won't be surprised if they sound the same, or different. Either way. Curious to see whether the CD is more condensed, as I hear it.

Because the DAC-on-a-chip solutions that are advertised by TI, ESS, AKM etc. (and advertised as being on board any number of budget devices) already feature exemplary oversampling capabilities that would put flagship CD players of yesteryear to shame.

 

[bigshot]

Every format is remastered for that format. You can’t compare a CD to a download. Two different things. The way to compare is to take a high data rate file and bounce it down to a lower data rate.

 

[Elegiac]

Ah. Interesting.

 

[71 dB]

Why not the DAC thing. About only higher-end DAC's and the oversampling.

Because oversampling isn't "rocket science." There is not reason why only a few high-end DACs could do it well.

Hmm. I'm not sure about different mixes. They should be the same mix. One on CD, and the other a FLAC file.

Perhaps they should be the same mix, but the notion of them sounding different to you indicates they are not. Having a different master for hi-res format is pretty common (otherwise people would notice no dfference).

I won't be surprised if they sound the same, or different. Either way. Curious to see whether the CD is more condensed, as I hear it.

Condensed as in dynamically more compressed?