Would you accept a LOSSY compression scheme for CD? Experiment inside... (1 Viewer)

[Javier_Huerta]

I was a bit surprised about DTS claiming their 96/24 tracks are "master quality" (such as in Queen's "A Night at the Opera"), and people claiming that DTS is inferior to CD, superior to CD, superior to Dolby Digital, et al...

So I decided to make a little experiment. I used David Gilmour's "In Concert" DVD as a source. I know the disc inside out, so I thought it would be quite fair. The disc has a PCM stereo track, 48KHz / 24 bit, which would suit my purposes just fine.

I then took the audio signal, applied an anti-aliasing filter to bring the signal down to 44.1 KHz, and then made a 44.1KHz/24 bit DTS CD with it. Other than the anti-aliasing process, it was an exact copy of the original bitstream. I then truncated the signal to 16 bits, and made a CD out of it.

I compared the 3 versions on a set of Etymotic ER-4S headphones connected to a Musical Fidelity X-CanV2 amp and a Luxman CD player connected to a Yamaha RXV-995 (for DTS processing).

The results amazed me. While the CD copy sounded as I would have expected it to sound (kinda dull compared to the 48 KHz, with less definition), the DTS CD was a virtually exact replica of the 48KHz / 24 bit stream. It sounded a lot more natural, fast and detailed than the 44.1 KHz. So much, in fact, it suddenly was very apparent someone could develop a lossy compression scheme and take PCM recordings to a new level in *every* medium.

The closest analogy I could think of would be comparing a 200Kb photo of a forest in GIF and JPG formats. While GIF would be a "lossless" compression scheme, JPG would deliver a sharper, crisper image with higher resolution and color depth.

I might be unto something here, or I might be completely nuts. I dunno.

 

[Felix Martinez]

I then took the audio signal, applied an anti-aliasing filter to bring the signal down to 44.1 KHz, and then made a 44.1KHz/24 bit DTS CD with it.

What DTS encoder did you use? Just curious. I author DVDs and would like to know people's experience with the different DTS encoders available.

Cheers,

 

[Javier_Huerta]

Minnetonka's SurCode DTS for CD audio.

Funny thing is, it can't take a 48KHz signal, but it can take a 24 bit one. My decoder's circuit was confused enough to detect it as a DTS DVD, not a CD (it lights the DTS indicator in different colors for different formats).

 

[Philip Hamm]

Take a listen to the DTS-ES Midnight Oil "Capricornia" CD. It states that it is at 44.1/24 DTS, my receiver only decodes 20 bit DTS I think (isn't 20 bit native for DTS and DD?). This DTS CD sounds absolutely stunning, equalling most of the DVD-Audio and SACD discs I've heard.

 

[Philip Hamm]

Wanna try another experiment? Get a $300 MiniDisc deck with ATRAC 4.5 or better and a digital in and out, use an external DAC, and see if you can tell honestly the difference between the original 44/16 and a MD copy.