I have a few classical CD marked with DDD, ADD and 4D recording, what do they represent? and their different

All I know is A=Analog, D= digital, and don't know when the Digital mastering has been invented , which one is better?

As far as I recall, the three letters refer to recording, mixing and transfer respectively, where A indicates analogue and D digital. Therefore a DDD disk is recorded, mixed and transferred digitally. The transfer is, of course, always digital! I've no idea what a "4D" designation means. DDD would be the best and AAD the worst, quality wise, all other things being equal.

The description of 4D I have seen:


As antz says, the initial "Master" in my list is the recording phase.

I would have said that DDD was the best, and AAD the worst; but I'm not so sure that it is as cut and dry as that...

No it's not that cut and dry. Digital recordings made before 88-89 did not always benefit from more modern oversampling techniques and thus a AAD might sound better. The actual equipment used to digitally master would also have an affect especially in the 80's and early 90's. This was something used more in the early days of CD as a marketing gimick as these days it should pretty much be DDD.

Exactly, and I'd even say quite a bit into the 90ies where the DDD pieces were suffering from poor AD and digital mixing quality.

Then, how about the sampling rate of master tape, is it 44k 16bit or much higher?

I think 4D refers to Deutsche Grammophone's proprietary dithering and downsampling method. Usually they couple this with another proprietary algorithm called Original Image Bit Processing. I think all of this refers to signal processing + dithering + downsampling. Similarly Sony Classical has Super Bit Mapping.

I think some of these processes probably color the sound as they involve some signal processing. I enjoy the DG legendary recordings which are pretty much all Original Image Bit processing applied. The sound quality is very high, especially given that some of these recordings are quite old.

Apart from that I shun ADD / AAD CDs if I have a choice. A modern DDD CD would almost certainly be higher fidelity. I've heard some people complain they sound too crisp and analog originals bring some warmth. It might be true but I don't mind it, whereas a bad ADD/AAD recording would be intolerable especially if hissing/noise annoys you.

Note: Would you please use the default size font?

...you either like it or you don't.

newer digital mixing is sometimes preferred, but it can really vary on the remaster process and/or who is doing it.

doing the mastering and mixing at >16bit/44.1khz has advantages.

for classical i really dislike hiss, which could be avoided more easily with DDD.


later

Which is "better" -- assuming the most important part, the performance, is worthwhile -- depends much more on the skill and artistry of the people doing the recording, mixing, mastering, and preparation than it depends upon whether or not things were done in the analogue domain, the digital, or partly in both. Digital might make some aspects easier but it does not, in itself, make a recording the least bit more enjoyable or worth listening to. So the true answer is that, aside from a certain curiosity value, those designations are meaningless. They are a remanant from advertising attempts to promote a, at the time, new media.

then, is it meaningful to put 80's~early 90's DDD audio into SACD or HDCD formats? (I mean that is the 44k 16 bit->SACD/HDCD improves the sound quality?)
And is SACD a perfect solution , closest to analog?

No. It's everything but "perfect". More like the opposite. It's very inneficient bitrate-wise, and DVD-A is better in every respect.

As to re-issuing old masters in hi-res formats, it has little sense, even if the characteristics of these formats had audible consequences (leaving apart the multi-channel capabilities).

Hmmm, I think SACD can sound excellent, depending on your playback equipment. Especially for 5.1 surround audio it is a great format.
If, for whatever reason, the recording engineer decides to record in DSD (SACD) format, it makes sense to put the same format on the consumer disc, instead of converting to pcm for DVD-A.
The SACD output can come very close to the analog source (mixer output). There is just more choice in high quality pcm DAC's than there is in DSD DAC's. My Philips dvd-player e.g. can play SACD but converts the signal to pcm because it only has a pcm DAC on board. That unfortunately doesn't do justice to the SACD potential.


For digital masters (2-ch 16 bit 44.1 kHz) you're probably right. But for analog masters it's a matter of choice whether to transfer them to dsd or pcm. Don't forget that both formats can be converted to the other, so both are relatively future safe.

Digital mastering started just before the cd was introduced, in the early 80's.
Any recording made before that date was probably "A"nalog, which doesn't mean it was inferior.
The main advantage of digital audio (or any other data) is that it can be stored and copied without any loss. Since an analog master is unique and fragile, it was common practice to send an analog copy to the (LP) mastering engineer.

4D, as far as I know, was Deutsche Grammophon's recording system to improve audio quality by making the analog signal path as short as possible by putting the AD converters close to the microphones (on stage) and use digital mixing consoles. This was a bit different from other DDD recordings since most of them used an analog mixing console to mix the microphone signals and have the AD converter after the (analog) mixer output. The audible advantages of the 4D system have been publicly disputed by recording engineer Tony Faulkner, who claimed that it was mainly a marketing strategy. Decide for yourself if 4D brings better quality. It did require so much recording equipment (truckloads) that some colleagues called it "4D(ays of setup)" :)