DTS/DD vs. CD Audio quality-opinions?

[mtrycraft]

mtrycraft: I admit to being very inexperienced with the technical details of digital formats, so I have to ask a question here. Every source I've been able to find tells me CD audio quality's bit rate is 1.4Mb/s, whereas DTS bit rate is 1.5 Mb/s. Masking and encoding aside, my simple math gives me a +0.1 edge to DTS over CD. What am I doing wrong here?
How is 1.5 not bigger, or more than 1.4???
My head is starting to hurt...
I do agree with you, bitrate isn't everything, one has only to compare MP3 with WMA files to realize that.
Still, my admittedly subjective test left me somewhat embarassed, as I previously had been telling my friends that there was no way a DVD concert's audio quality could top that of a CD...boy was I wrong.

I am pretty sure that DTS bit rate is for all channels, not one channel as in CD.
That would make DTS bit rate of about 7.5Mbits/sec+. I seriously doubt that.
Why not ask Sir Terrence at HT.

[kexodusc]

mtrycraft: That would better explain the relative file sizes between CD and DTS tracks, good thinking man...
Curious, if theres a bit of information being translated back into audio information, does it matter what channel it is emitted from as long as the sound is being reproduced?
Certainly each channel in stereo would have more detail than its counterpart in 5.1, but the cumulative effect...never mind...I'm obviously in way over my head...sigh...getting old...
Well, I've opened a whole can of worms with this thread. Curious as I am, I have to know how and why everything works, sometimes at the expense of enjoyment.
I'm going to have to learn to get past that.
Things were so much simple with vinyl...

[maxg]

Curious, if theres a bit of information being translated back into audio information, does it matter what channel it is emitted from as long as the sound is being reproduced?
Certainly each channel in stereo would have more detail than its counterpart in 5.1, but the cumulative effect...never mind...I'm obviously in way over my head...sigh...getting old...
Well, I've opened a whole can of worms with this thread. Curious as I am, I have to know how and why everything works, sometimes at the expense of enjoyment.
I'm going to have to learn to get past that.
Things were so much simple with vinyl...

No it doesnt matter which channel is being reproduced. It does matter, however, when there are 6 channels being reproduced together.

Vinyl has its own complexities but ultimately is probably more simple to understand. Another reason I have re-embrased it....

[Sir Terrence the Terrible]

I am pretty sure that DTS bit rate is for all channels, not one channel as in CD.
That would make DTS bit rate of about 7.5Mbits/sec+. I seriously doubt that.
Why not ask Sir Terrence at HT.

The Dts bit rate is spread over the 5.1 channels. For DVD the bitrate is 1509kbps. To understand how Dts(and DD potentially)can sound better than 16/44.1 you must understand how the encoding process works. To put in in simple terms Dts encoding discards signals that are masked and rendered inaudible by louder adjacient signals(precedence effect) Once those signals are discarded the encoding process breaks down these signals by frequency. These signals are encoded into the Dts bitstream at 20 bit depths. So what you hear is 16/44.1khz signals at 20/48khz resolution. Because more bits are used, and a slightly higher sample rate, you get lower noise and greater dynamic range. Where Dts has the edge over DD lies in Dts's ability to encode not only the primary signals, but it also codes the sub band frequencies as well because it has the bits to do so.

One would think that uncompressed 16/44.1khz PCM should sound better than compressed 20/48khz. But 16/44.1khz contains signals that are heard, and unheard so in theory because of the masking effect of louder signals in relationship to the softer unheard signals, you are not hearing more detail. Dts and DD more efficiently code signals that ARE heard with more resolution, lower noise and greater dynamic range(CD has a dynamic range of 96 db and Dts has about 120db)

[mtrycraft]

. So what you hear is 16/44.1khz signals at 20/48khz resolution. Because more bits are used, and a slightly higher sample rate, you get lower noise and greater dynamic range.

This can only be true if the master had the 20 bit depth. If your source is only 16 bits, that is all you can hope to ever get. But I would defer this to better experts in th efield, beyond both of us. Sorry.

But 16/44.1khz contains signals that are heard, and unheard so in theory because of the masking effect of louder signals in relationship to the softer unheard signals, you are not hearing more detail.

Yes,
That is exactely why perceptual coding works so well.

[kexodusc]

Wonderful explanation Terrible T, simple, logical, and easy to follow. At least now I have a better grasp of the variables involved and their impact on sound quality.

[Sir Terrence the Terrible]

. So what you hear is 16/44.1khz signals at 20/48khz resolution. Because more bits are used, and a slightly higher sample rate, you get lower noise and greater dynamic range.

This can only be true if the master had the 20 bit depth. If your source is only 16 bits, that is all you can hope to ever get. But I would defer this to better experts in th efield, beyond both of us. Sorry.

But 16/44.1khz contains signals that are heard, and unheard so in theory because of the masking effect of louder signals in relationship to the softer unheard signals, you are not hearing more detail.

Yes,
That is exactely why perceptual coding works so well.

Well Mtry, its not as simple as 16 bits is all you get when you speak of encoding to Dts(or any high bit perceptual encoder). Remember, during the coding process you are getting rid of unheard signals. That includes the floor noise, and any signal that have louder adjoining signals. It is then re-encoded at 20bits at 48khz sampling. While the sampling doesn't necessarily raise the cutoff frequency(the 16bit audio has already limited that to 22.050khz) you will lower the noise floor and get an increase in dynamic range as a result. The audio is also reclocked(which would reduce any process inducing jitter) which aids in smoothing the more complex instrument textures(strings, cymbal crashes glocks and high brass). So you may only have a 16 bit master, but there are some 20 bit performance features you get from coding the information at 20 bits

[hertz]

2 channel redbook audio cd if mastered properly will sound better than DD or DTS anyday for the simple reason that both DTS and DD use lossy compressions.The test that you did proves any of the following:
1.Your audio setup is better for movies than stereo.
2.Some audio cds are mastered very badly.There is a chance that the newer DTS or DD version could have done a better job.THIS DOES NOT PROVE THAT DD OR DTS FORMAT IS BETTER.

[av_phile]

2 channel redbook audio cd if mastered properly will sound better than DD or DTS anyday for the simple reason that both DTS and DD use lossy compressions.The test that you did proves any of the following:
1.Your audio setup is better for movies than stereo.
2.Some audio cds are mastered very badly.There is a chance that the newer DTS or DD version could have done a better job.THIS DOES NOT PROVE THAT DD OR DTS FORMAT IS BETTER.

There are good and bad recordings in every formats. How a performance is captured and how well it is encoded in LP, CD. or DVD is what matters. The recording engieners or the studio has lot to do in making excellent or lousy recordings in whatever media. The exception being the cassette format which is really technically inferiror as an analog medium.

But I tend to agree with Sir Terenece's brillant laymanish explanation of the difference between CD and DD/DTS. At first glance you would think that because DD/DTS uses lossy compression versus uncompressed encoding in CDs, that the former is inferior. But psychoaccoustic-based compressions simply discard what are unnesessary in the encoding process, thus leaving more room for the more audible segments of the musical passage to get more bits. CD's uncompressed format allocates the same 16-bit word length even for complete silence. I consider that an unnecessary waste.

Hence, DD/DTS sound works wonderfully to make prominent instruments sound more detailed. I, too, have experienced hearing some sonic detailing and spatial depth in DD/DTS that I did not hear with CDs of the same title. Even the instrumental balance is different. I cannot say outright that DD/DTS is better, Some are. Like I said there are good and bad titles in every format. DD/DTS definitely sound dfifferent in a way that gives a totally new listening experience. I can only assume that the reocrding engineers who revisited the old multi-track masters did a good job at remixing into multi-channel and DD or DTS format. I can speak of the George Benson Breezin' reocridng which I had as an LP, then CD and now in DVD-Audio where I only play the DD tracks as I still don't have a universal player. Same with Fourplay, I have the CD and the DVD-A. Much as I am a stereophile, I must admit I get more instrumental detailing and depth in multi-channel playback of these recodings.

However, I must admit that not all DD/DTS transcriptions are an improvement over their CD counterpart. I find The King and I DVD soundtrack no better that the CD soundtrack. Same with the Fiddler On The Roof. However, the My Fair Lady DVD sound has more body than the CD soundtrack of the same. But that's just me.

[Sir Terrence the Terrible]

2 channel redbook audio cd if mastered properly will sound better than DD or DTS anyday for the simple reason that both DTS and DD use lossy compressions.The test that you did proves any of the following:
1.Your audio setup is better for movies than stereo.
2.Some audio cds are mastered very badly.There is a chance that the newer DTS or DD version could have done a better job.THIS DOES NOT PROVE THAT DD OR DTS FORMAT IS BETTER.

This information isn't quite correct. All a lossey codec does is pack signals more efficently. Any signals removed are below the threshold of hearing anyway, so it doesn't matter that there are discarded. 2 channel redbook CD does not have the dynamic range or the spatial deminsionality of either Dts or DD. Redbook CD does not have the flexibilty of bitrate, bit depth, or sample rate that Dts has. Redbook CD does not have the LFE channel which can be used for more bass impact. Dts(and DD for that matter) can have a lower noise floor than redbook CD.

A well mastered Dts CD with the highest bit rate can sound identical to the master tape. It also has the benefit of multichannel to properly place ambience where it belongs, to the sides and rear. It can operate on the fly, and transparently in a lossey, or lossless mode depending on the complexity of the original PCM signal.

So to say the redbook CD will sound better than Dts and DD based on the sole fact that they are lossey is not factual and just shows a lack of understanding of lossey codecs, and how they encode audio.