March Audio Posted March 6, 2021 Share Posted March 6, 2021 On 10/8/2020 at 5:08 PM, semente said: Satisfied that PCM digital was an improvement over analog tape, Denon engineers set out to develop their own VTR-based system. Their goals were improved audio quality and multi-track recording capability, which then made the system viable in most commercial recording settings of the 1970s. In 1972, Denon unveiled the DN-023R, an 8-channel system featuring 13-bit resolution and a sampling rate of 47.25kHz. The system used a Hitachi (then called Shiba Electronics) 4-head open-reel broadcast VTR as its storage format. Anazawa noted: "We used the low-band mode of the VTR, for black and white (video). The reasons were stronger (performance) than color mode for tape drop-out and less cost." Anazawa said, with the DN-023R, "we could edit music recordings and cut (LP) discs using advanced (preview) head" to control lathe-automation. Denon deployed the DN-023R system immediately and used it to make commercial-release recordings throughout the 1970s. The first LP made with this system was Nippon Columbia NCC-8501, Mozart: String Quartets K. 458 and K. 421 by the Smetana Quartet. This album was recorded 24-26 April 1972, at Aoyama Tower, Tokyo, and released in October 1972. Denon also released at least six other digital-recording LPs in October 1972, including classical, jazz and traditional Japanese music selections. Denon also made the first commercial digital recording in Western Europe, at Notre Dam de Rose outside of Paris on 2-3 December 1974, Bach "Musical Offering" BWV 1079, by the Paillard Chamber Orchestra. The LP was released in May 1975. In The Dawn of Commercial Digital Recording by Thomas Fine (attached) Fine_Dawn-of-Digital.pdf 5.71 MB · 33 downloads The BBC started using PCM feeds to FM transmitters in 1972. Some People still quote how good they think their analogue FM tuner sound is compared to digital sources. If only they knew 😉 erin 1 Link to comment
Popular Post bluesman Posted March 6, 2021 Popular Post Share Posted March 6, 2021 I do almost all of my recording at 32 bit floating when using a DAW or other form of recording software (Ardour, Audacity etc). It offers far more headroom - what appears to be mild clipping is almost always just an artifact of the metering strip rather than true distortion. I find that I can normalize, compress, or otherwise bring down the gain and reveal accurate peaks hidden above the line. And there's a lot of leeway for DSP without affecting the audible signal at all. There are a lot of "disposable" bits, so SNR remains quite high, for example. Once all the tracks are right and the mixdown is what I want, I make a Redbook master. When I rip vinyl, I also use 32 bit float, normalize, clean up and label the rip, save it as a Redbook file &/or a FLAC (depending on what I'm going to do with it). Here's a good discussion for those who are interested. R1200CL and Mike48 1 1 Link to comment
fas42 Posted March 7, 2021 Share Posted March 7, 2021 6 hours ago, March Audio said: The BBC started using PCM feeds to FM transmitters in 1972. Some People still quote how good they think their analogue FM tuner sound is compared to digital sources. If only they knew 😉 Only 13 bits accuracy, in fact ... Link to comment
Rexp Posted March 7, 2021 Author Share Posted March 7, 2021 12 hours ago, bluesman said: I do almost all of my recording at 32 bit floating when using a DAW or other form of recording software (Ardour, Audacity etc). It offers far more headroom - what appears to be mild clipping is almost always just an artifact of the metering strip rather than true distortion. I find that I can normalize, compress, or otherwise bring down the gain and reveal accurate peaks hidden above the line. And there's a lot of leeway for DSP without affecting the audible signal at all. There are a lot of "disposable" bits, so SNR remains quite high, for example. Once all the tracks are right and the mixdown is what I want, I make a Redbook master. When I rip vinyl, I also use 32 bit float, normalize, clean up and label the rip, save it as a Redbook file &/or a FLAC (depending on what I'm going to do with it). Here's a good discussion for those who are interested. When you say you record at 32 bit, what ADC are you using? Link to comment
Popular Post bluesman Posted March 7, 2021 Popular Post Share Posted March 7, 2021 5 hours ago, Rexp said: When you say you record at 32 bit, what ADC are you using? The ADCs I own are all 24 bit fixed point. The input is converted to 32 bit floating in the computer. As I understand it, 24 bit signals map into 32 bit float well. A 32 bit float with normalization and size bit gives the equivalent of 25 bits of mantissa. This doesn’t change the signal going into the computer - it improves the process of recording, editing, processing etc and yields a better stereo output. I still have to be careful with signal levels from individual mics and instruments. Where it helps is in the master bus. As I add more individual tracks, the master level goes up and I have to bring it down successively as I lay down more tracks. With 32 bit float recording, minor peaks above 0 dB in the master track do not require reducing the gain. I used to have to stop recording and cut the gain because the master would clip if I didn’t check and correct the input volume before recording the next track. I can post-process the 32 bit tracks with impunity and use the stereo master directly for export as a 16 or 24 bit wave or FLAC. This is more useful for live recording than for vinyl ripping, but I set my DAWs to default to 32 bit. So I use the same settings for ripping. Rexp and John Dyson 1 1 Link to comment
John Dyson Posted March 7, 2021 Share Posted March 7, 2021 1 hour ago, bluesman said: The ADCs I own are all 24 bit fixed point. The input is converted to 32 bit floating in the computer. As I understand it, 24 bit signals map into 32 bit float well. A 32 bit float with normalization and size bit gives the equivalent of 25 bits of mantissa. This doesn’t change the signal going into the computer - it improves the process of recording, editing, processing etc and yields a better stereo output. I still have to be careful with signal levels from individual mics and instruments. Where it helps is in the master bus. As I add more individual tracks, the master level goes up and I have to bring it down successively as I lay down more tracks. With 32 bit float recording, minor peaks above 0 dB in the master track do not require reducing the gain. I used to have to stop recording and cut the gain because the master would clip if I didn’t check and correct the input volume before recording the next track. I can post-process the 32 bit tracks with impunity and use the stereo master directly for export as a 16 or 24 bit wave or FLAC. This is more useful for live recording than for vinyl ripping, but I set my DAWs to default to 32 bit. So I use the same settings for ripping. Yes -- certain kinds of processing and mixing like to use more bits than just 16. Certain kinds of processing like rates at least 1.5X to 2X normal Nyquist rate (at least 66.15k if done carefully, or 88.2k/96k if some leeway is needed.) I suggest just 96k and be done with it. Sometimes even some processing might benefit from 192k, but I haven't run into my self. FP is 'the way to go' though for processing -- eliminates a lot of internal SW troubles. Link to comment
Rexp Posted March 8, 2021 Author Share Posted March 8, 2021 12 hours ago, bluesman said: The ADCs I own are all 24 bit fixed point. The input is converted to 32 bit floating in the computer. As I understand it, 24 bit signals map into 32 bit float well. A 32 bit float with normalization and size bit gives the equivalent of 25 bits of mantissa. This doesn’t change the signal going into the computer - it improves the process of recording, editing, processing etc and yields a better stereo output. I still have to be careful with signal levels from individual mics and instruments. Where it helps is in the master bus. As I add more individual tracks, the master level goes up and I have to bring it down successively as I lay down more tracks. With 32 bit float recording, minor peaks above 0 dB in the master track do not require reducing the gain. I used to have to stop recording and cut the gain because the master would clip if I didn’t check and correct the input volume before recording the next track. I can post-process the 32 bit tracks with impunity and use the stereo master directly for export as a 16 or 24 bit wave or FLAC. This is more useful for live recording than for vinyl ripping, but I set my DAWs to default to 32 bit. So I use the same settings for ripping. Being a noob at this I thought I preferred 24/32 bit but in fact I was recording at 16/48 with Audacity converting to 32/44.1. If I set Audacity to convert to 16/44.1 it sounds worse. Link to comment
fas42 Posted March 8, 2021 Share Posted March 8, 2021 21 minutes ago, Rexp said: Being a noob at this I thought I preferred 24/32 bit but in fact I was recording at 16/48 with Audacity converting to 32/44.1. If I set Audacity to convert to 16/44.1 it sounds worse. Do you have Audacity set to Best Quality, in the Quality Preferences? Link to comment
opus101 Posted March 8, 2021 Share Posted March 8, 2021 On 3/7/2021 at 8:32 AM, fas42 said: Only 13 bits accuracy, in fact ... http://www.audiomisc.co.uk/BBC/PCMandNICAM/History.html fas42 1 Link to comment
Rexp Posted March 8, 2021 Author Share Posted March 8, 2021 11 minutes ago, fas42 said: Do you have Audacity set to Best Quality, in the Quality Preferences? Default setting, it say Medium Quality for Real-time conversion and Best Quality for High-qualty converstion. Link to comment
fas42 Posted March 8, 2021 Share Posted March 8, 2021 Just now, Rexp said: Default setting, it say Medium Quality for Real-time conversion and Best Quality for High-qualty converstion. Okay, I have mine Best Quality for both, and Dither, for both, set to None - and Default Sample Format, 32 bit float ... if not that, see if it makes any difference. Link to comment
Rexp Posted March 8, 2021 Author Share Posted March 8, 2021 7 minutes ago, fas42 said: Okay, I have mine Best Quality for both, and Dither, for both, set to None - and Default Sample Format, 32 bit float ... if not that, see if it makes any difference. I did play around, couldn't improve it. Its the Real-time setting that applies to recording I guess? Link to comment
Popular Post bluesman Posted March 8, 2021 Popular Post Share Posted March 8, 2021 10 hours ago, Rexp said: I did play around, couldn't improve it. Its the Real-time setting that applies to recording I guess? When in doubt, read the manual: The "Real-time" options are only used when converting sample rates or formats for playback in Audacity. The "High-quality" options are used for sound that is being converted for storage on disk, for example when rendering or exporting. Default Sample Format: This sets the Sample Format (bit depth) which will be used each time Audacity is launched, or each time a new project window or track is opened. It offers a choice of three sample formats or bit-depths. This affects both imported and newly recorded material, either in a new or existing project (even if the other audio in an existing project is at some other quality). There's a window in the lower left corner of Audacity's GUI to set resolution for a project when you start it. That's where you can set your preferred sampling rate if you don't want to use the default you chose in Preferences. But you have to go to the Quality panel in Preferences to change the sampling format (16, 24, 32 floating). Regardless of the sample rate you choose in that select menu, the default sample format will be used. Then there's this: On Windows, Audacity cannot record at greater 16-bit with MME or WASAPI as the host - you need to use Windows Direct Sound if your sound device supports a bit depth of more than 16-bits. Reading manuals is tedious, but the rewards are many. For starters, you'll end up spending less time (often a lot less time) struggling to find settings that work and controls that do what you're trying to do. Rexp and fas42 1 1 Link to comment
bluesman Posted March 8, 2021 Share Posted March 8, 2021 10 hours ago, fas42 said: Okay, I have mine Best Quality for both, and Dither, for both, set to None - and Default Sample Format, 32 bit float ... if not that, see if it makes any difference. Dithering helps most in the 16 bit format. Truncation distortion is present in 24 bit representations but at a much lower level. If recording and saving your projects entirely at 32, you probably don’t need to dither at all. But if you’re exporting to 16 or 24 bit FP wavs or converting wav to FLAC, you should probably dither once on the master stereo tracks before export / conversion. That’s what I and many real recording engineers do. Link to comment
davide256 Posted March 8, 2021 Share Posted March 8, 2021 The thing to remember about CD rate is that it was a compromise based on assumptions around dynamic range and audible distortion from sampling rate. Most of the time it works well if engineered correctly for dynamic range. Lately I've begun to suspect that 48/24 is all thats really needed and that higher rates are just to aid the less than perfect electronics we all struggle with. Regards, Dave Audio system Link to comment
davide256 Posted March 8, 2021 Share Posted March 8, 2021 deleted Regards, Dave Audio system Link to comment
John Dyson Posted March 10, 2021 Share Posted March 10, 2021 On 3/8/2021 at 8:47 AM, davide256 said: The thing to remember about CD rate is that it was a compromise based on assumptions around dynamic range and audible distortion from sampling rate. Most of the time it works well if engineered correctly for dynamic range. Lately I've begun to suspect that 48/24 is all thats really needed and that higher rates are just to aid the less than perfect electronics we all struggle with. I agree with you 100% about 48k/24 for distribution and listening. Certain processing can require higher rates, but I don't really think that we are focusing on production issues. (Lossless and trivial rate conversion can be done if processing is needed -- so 48k/24 is even a technically plausible rate for professional interchange because integral rate conversion is essentially perfect and totally trivial to do.) Frankly, 44.1k makes me nervous, but in the margins, works well enough. But, why not 48k except for CDs? And about the #bits, why not 24bits nowadays? Even if the benefit really stops at 17-18 good bits, 24bits is nice, even number. Of course, like the sample rate fraud that goes on, it is easy to create false, simply dithered bits to sell 'higher quality'. So I agree, 48k/24, is the best tradeoff in my opinion. Link to comment
Rexp Posted March 11, 2021 Author Share Posted March 11, 2021 Review here of Mytek ADC, he found the live conversion transparent at 24/192 but when playing back the recorded files much preferred DSD. Go figure. https://positive-feedback.com/reviews/hardware-reviews/mytek-audios-brooklyn-adc/ Link to comment
jabbr Posted March 11, 2021 Share Posted March 11, 2021 On 10/7/2020 at 9:59 PM, Rexp said: I've been recording some stuff using Audacity, it sounds better at 24 and 32bit than 16bit (sample rate 44.1 in all cases). Now I'm a believer that Redbook should be enough, however I'm not sure modern ADC's are capable of capturing accurately at 16bit. Some Objectivist members like @Archimago record at 24bit so the question is, is 16bit good enough? (forget studio requirement for extra processing bandwidth) From a purely objective standpoint you can look at the dynamic range and noise floor of the signal you wish to record and then decide whether an ideal 16 bit recording is capable, then decide if you wish to allow any error in level settings etc. Custom room treatments for headphone users. Link to comment
Rexp Posted March 12, 2021 Author Share Posted March 12, 2021 1 hour ago, jabbr said: From a purely objective standpoint you can look at the dynamic range and noise floor of the signal you wish to record and then decide whether an ideal 16 bit recording is capable, then decide if you wish to allow any error in level settings etc. True. I'm happy with 16 bit for recording but only when Audacity upconverts it to 32 bit float. Any objective reason for that? Link to comment
fas42 Posted March 12, 2021 Share Posted March 12, 2021 6 minutes ago, Rexp said: True. I'm happy with 16 bit for recording but only when Audacity upconverts it to 32 bit float. Any objective reason for that? How are you listening to the output - just via Audacity's inbuilt player? Link to comment
Rexp Posted March 12, 2021 Author Share Posted March 12, 2021 1 minute ago, fas42 said: How are you listening to the output - just via Audacity's inbuilt player? Yes Link to comment
fas42 Posted March 12, 2021 Share Posted March 12, 2021 Okay, you're getting the complication of how Audacity's processing, while playing, is affecting things - do you have a "best audio player" piece of software that you use on that PC? If so, what happens if you export what you record in different formats, and play those files with that preferred player? Link to comment
Rexp Posted March 12, 2021 Author Share Posted March 12, 2021 36 minutes ago, fas42 said: Okay, you're getting the complication of how Audacity's processing, while playing, is affecting things - do you have a "best audio player" piece of software that you use on that PC? If so, what happens if you export what you record in different formats, and play those files with that preferred player? I mentioned earlier in the thread if I down convert it sounds worse. This is irrespective of the player used. Link to comment
fas42 Posted March 12, 2021 Share Posted March 12, 2021 So, you export using 16-bit PCM encoding in one instance; and 32-bit float in the other - so the latter file is twice the size ... just to confirm? Link to comment
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