analog or digital? (1993)

(via travis)

Comments

  1. That is a nice sum-up of a couple of common misconceptions about digital audio😉

    • Agreed. There was even an experiment (sorry couldn’t find a link) where people were to compare hd audio recordings with the same audio reduced to 44100/16 bit. Of course participants couldn’t tell which is which.
      What those guys in video talking about is probably overcompression and limiting artifacts, that spoiled cd audio.

  2. travelmusicstuff says:

    Back in 1993, digital was in it’s infancy and analogue has arguably plateaued. Not really a fair comparison is it? Brick wall limiting also probably had something to do with it.

  3. I think 16b/44k recording does not as good as properly aligned analog tape. 24b/96k however sounds fine to me, even if converted and dithered to 16b/44k! It is ironic that now that we can make good sounding CD’s at last, people go back to vinyl. @travelmusicstuff: brickwall limiting sucks!

  4. The thing nobody mentions is the fact that every real expert at the time considered 20 bits at 50-60kHz sample rate to be the absolute minimum allowing transparency.

    We got 44.1×16 because it was the highest resolution that was compatible with Sony’s digital audio stored as video format that Phillips used to turn their video disk into the CD. A lot of people don’t realize that CDs are mostly manufactured on vinyl replication presses. Then Sony and Panasonic railroaded us into 48kHz x 20 bits for video.

  5. “brickwall limiting sucks!” This is just wrong. Limiting was necessary to create vinyl records. Yes records required limiting simply because vinyl is very ……limited in it’s ability to reproduce certain frequencies. That is part of the “warm” sound that people hear when they listen to vinyl. Personally, I like the sound of a well produced cd over vinyl. There. I said it. To my ears a well produced cd or digital file can sound as good and as warm or better than any record. There are plenty of ways to warm up digital sound now. The video may have been true at one time but not anymore.

    • @hue: In the time we cut vinyl there was never such a thing as brick-wall limiting. What I meant was the senseless short-term cutting of the peaks that make audio to what it is. Brick-wall limiting is a digital invention. In analog we just could not cut the peaks fast enough to achieve that. Brick-wall limiting can be a good tool, but in general we would be better off if it was never invented, as far as I’m concerned. I agree that a good produced CD can sound better than vinyl. But there are not much good sounding CD’s out there! Please note that this is just a personal opinion.. I do not want to offend anyone!

      • So….what about the 1176? That’s a classic(1966) Limiting amplifier. It was around well before digital and has a compression ratio of 20:1. That’s brick wall limiting. Not trying to be argumentative but ….

        • Hi Hue! In analogue terms we call a compressor a limiter when it’s got a ratio of 6:1 or higher and if it analyses peaks instead of RMS values. When mastering vinyl an analogue limiter indeed was a standard item. No argues there. The 1176 is an excellent limiter. However it is not a brick-wall limiter at all. This has not much to do with ratios, but the more with speed. The problem with designing a brickwall limiter is that you can only reduce peaks once you measured they are there, and then you would be too late as your CD will already distort. Because analogue electronics take some time to analyse the signal before they can reduce the peaks there will always be quite some overshoot. You could not bring a CD to the current hot levels with it without getting a lot of distortion. Instead you would have to preserve a little headroom (maybe 6 db or so) for the overshoots. (as you probably figuered by now, I prefer that!) So, if a limiter is analogue, it either uses distortion or it is not brick-wall. Actually within the digital domain we had the very same situation until someone (maybe waves?) build an limiter that uses a delay between the analysis and the reduction stage solving the timing problems, allowing limiting to be instant and reduce all peaks at all times. This technique is known as ‘look ahead’. Without look ahead brickwall limiting cannot exist. The sound is entirely different as the overshoot is the thing that makes the 1176 or other analogue limiters sound as if some of the original dynamics were preserved. The Waves L1 is the first brickwall limiter I can remember using and it had a ratio of 1000:1, but it is very possible that it was DBX or another company . I guess the L1 saw the light in the early 90’s. This is in short the difference between limiting and brickwall limiting as I understand it.

          • Thanks for clearing that up. I just don’t like reading blanket statements like______sucks. There’s a place for every tool.

  6. With vinyl the only thing brick-wall limiting could buy you were lower cutting levels due to the tracking and cutter amplifier overload problems the extra distortion caused.

    • Well, it was never used to attain loudness the way it is today. Only to prevent distortion as it was originally designed for.

  7. ALoserMakesFakes says:

    As an audiophile I admit exactly what guys in the video are saying except the stair-like representation of digital audio data. It is a bloody violation of digital sampling theorem and would give people a serious headache when they try to understand why 1-bit digital audio system can capture and reproduce sound.

    I don’t think that a matter of compression artifact but of design of DACs in main. They used non-oversampling multi-bit DACs for CD players. The DACs will have the worst distortion at zero-crossing points of audio signals because every man-made resistor has a certain error, then resistor of the highest value switches at zero-crossing during DA conversion. This means that CD players of that time were pretty poor at reproducing nuances of small sounds by nature.

    Moreover, people rarely thought about jitter performance then. Actual dynamic range shrinks as jitter increases, therefore we need 120ps or less of clock jitter at DA conversion only to guarantee the quality of 16/44.1kHz PCM data. If you want to give some meaning to dither or noise-shaping of the data, jitter has to be much better than this.

    • I think the most common problem is that many analog measurements don’t legitimately apply to digital converters. For example most converters mute when no signal is present making dynamic range “measurements” utter fiction.

      Jitter is actually a new name for good ol’ wow and flutter so they could advertise zero wow and flutter. Like wow and flutter, jitter combines the recorded frequency modulation spectrum with that of the playback producing a sum and difference spectrum that can very much be audible depending on the particular gear and clocking. Sadly it’s a moving target so what sounds good with one pair of converters can sound bad if you swap one of the converters for something else. Measuring either out of context of the other is utterly meaningless.

      On top of it all is the fact that our hearing ranges or focuses which means artifacts a hundred-plus dB. down will be perfectly audible if somebody happens to notice them and the likelihood of that happening varies with both the program material and the particular listener’s hearing. Ironically people having hearing damage can often hear digital artifacts or the lack of dithering more easily than people having excellent measured hearing! The only way you can do a meaningful blind test is by training subjects to hear a specific artifact and then reducing it until the test results become random. Most so-called blind tests ignore how hearing works and are thus intellectual fraud because they will virtually always produce random results.

      • Ironically people having hearing damage can often hear digital artifacts or the lack of dithering more easily than people having excellent measured hearing!

        We once had a mp3 codec shoot out and indeed that guy who was (one side) hearing impaired was able to spot most of the differences opposed to the others. Unbelievable but true …

        • This is because hearing damage destroys specific bands beginning in the upper midrange making the person less capable of masking aliasing and truncation artifacts. I have a few mastering clients who can spot changes to dither in a heartbeat.

  8. Dean Aka Nekro says:

    Bob and Herbert, Thank you for that information. Really intresting to me and am always looking to further my own knowledge. So I learned something today. I am far from an audiophile (Although I am not into listening to or creating way beyond slammed audio, I just do not buy into the loudness war as anything but marketing to be honest), Unlike audiophool’s I do not hear snake oil or buy into any of that either (Yeah that hi-fi setup which set you back more than paying off the whole morgage on your house is obviously worth it, Since most albums were engineered, mixed and mastered with such gear that probably by these days budgets/studio setups bar the biggest boys cost less than your auidophool approved hi-fi haha, Of course every audiophile can hear the difference in thier newest, latest, shiny + snake oil laced system than the old one, Just do not expect your friend’s to do the same, They may agree with you for the sake of sympathy mind). Regarding brickwall limiters the one I find most amusing is TC Electronic releasing thier Finalizer way back when with a little introduction note from Bob Katz, Nowadays they have him lecturing/smirking over similar tools as propaganda for the virtues of why thier latest Loudness metering is MUST HAVE/which they wish to become a standard, Obviously they are a business and alot of R&D plus time went into the product no doubt. I would probably do that for all the free kit TC would send my way though so it is nothing against Mr.Katz, The one record which he mastered by a german technical death metal band sounded really weak and thin (Necrophagist’s ‘Epitaph’ from 2004), Apart from that I am not at all familar with any of the man’s work. TC’s Finalizer was released IIRC in 1996 and DBX’s take on the same idea ‘Quantum’ was released around 1999 when the Finalizer Express was released and then Finally thier Finalizer 96k in 2000 (I could be wrong on the dates but roughly should be close enough). Do not know when the first plug-in brickwall limiter was released as I was not ITB back then. Damned now anyone know if I can get a free LM-6 Loudness Meter if I can provide TC Electronic full proof of purchase of my old and pure evil Finalizer 96k?

    Cheers and all the best to all as always

    Dean

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