DTS/DD vs. CD Audio quality-opinions?

[kexodusc]

We did compare the multi channel, but we were listening for detail. We also compared 2.0 Dolby Digital, on a few which still clearly sounded more detailed and natural. Maybe this is the norm, but I was previously under the impression that Dolby Digital and DTS were lossy forms of compression that didn't quite measure up to CD (which is limited in itself).

[mtrycraft]

We did compare the multi channel, but we were listening for detail. We also compared 2.0 Dolby Digital, on a few which still clearly sounded more detailed and natural. Maybe this is the norm, but I was previously under the impression that Dolby Digital and DTS were lossy forms of compression that didn't quite measure up to CD (which is limited in itself).

CD is not a lossy format, DD and DTS are. CD is limited to human perception capability, or the vast majority of it.
Perhaps your listening protocol has something to do with this? One may have been a little louder than the other?

[kexodusc]

We had to adjust volumes, as the DVD's generally seemed louder than CD source.
I understand the lossy encoding nature of DTS/DD. I wonder, since DTS has a higher bitrate than CD audio, and both have higher sampling rates and use 24 bit wordlengths, does this over come the "lossy compression" set back?.
Is it possible that compressing a 24 bit, 48 kHz audio track could sound better than CD's 44.1 kHz, 16 bit signal without compression?
What I'm really looking for is a decent article or link comparing the three formats, I haven't been able to find one that compare sound quality with fundamentals to support the analysis.

[mtrycraft]

We had to adjust volumes, as the DVD's generally seemed louder than CD source.
I understand the lossy encoding nature of DTS/DD. I wonder, since DTS has a higher bitrate than CD audio, and both have higher sampling rates and use 24 bit wordlengths, does this over come the "lossy compression" set back?.
Is it possible that compressing a 24 bit, 48 kHz audio track could sound better than CD's 44.1 kHz, 16 bit signal without compression?
What I'm really looking for is a decent article or link comparing the three formats, I haven't been able to find one that compare sound quality with fundamentals to support the analysis.

DTS cannot be higher bit rate than CD as it is perceptually coded, information is discarded that is deemed inaudible due to masking. Same with DD or any perceptual coding. The bit rate is not everything but the algorythm used is. That is what calculates and discards inaudible signals.
DTS/DD has 5.1 channels too, so that may explain what you may be thinking.

I am not aware of any reliable DBT comparisons on the three.

[Woochifer]

DTS cannot be higher bit rate than CD as it is perceptually coded, information is discarded that is deemed inaudible due to masking. Same with DD or any perceptual coding. The bit rate is not everything but the algorythm used is. That is what calculates and discards inaudible signals.
DTS/DD has 5.1 channels too, so that may explain what you may be thinking.

I am not aware of any reliable DBT comparisons on the three.

Impossible to do a DBT like you specify given that there are no soundtracks I'm aware of that have two-channel 16/44.1 PCM, DD, and DTS tracks that were encoded simultaneously.

[kexodusc]

DTS cannot be higher bit rate than CD as it is perceptually coded, information is discarded that is deemed inaudible due to masking.

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.

[maxg]

It may be that you have proved that your system is better at surround sound that at stereo. Repeating the experiment in a 2 channel only environment might yield very different results (it did for me).

Also worth mentioning that when I have compared DVD's to CD's using the 44.1/16 bit soundtrack on the DVD the CD has generally sounded way better. case in point Elton John double album of greatest hits which I have on DVD, CD and vinyl. The DVD is so bad in comparison to the other 2 it aint funny.

I have other examples (but cant remember them as I type):

As for your DTS throughput figure - that is for 6 channels of audio as compared to CD's 2 channels. DTS does seem to sound better than the equivalent DD5.1 tracks but I am not sure for music it beats CD (in 2 channel format).

[kexodusc]

Maxg: You are very much right. The CD in 2 channel sounded a way more real than Dolby Digital in stereo, I wouldn't compare those two formats. 2-Channel Dolby Digital seemed to have way too much bass output at the sub, had to be turned back a bit. Might just be the setup we used.

As far as my "test" results go, I don't think I've found much at all, nothing of any reasonable value to anyone at least. If everyone would go back and read the original post, you'll see I was looking for any kind of scientific support to reinforce our very subjective test. Like any subjective test, 4 different people could use the same equipment, the same sources, and have the opposite results too. I was just wondering if there was any science out there to support our result...don't think I'm going to find it now.

At this point, I might consider doing the test again, but with a soundmeter to more accurately measure volumes. I also wonder how much the studio engineering influences the results...maybe more detail was given to the 5.1 tracks than the stereo tracks? I don't know.

Thanks to all who have posted, by the way...some food for thought

[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...

[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)