Talk:Dolby noise-reduction system

message: This page should probably have a discussion of Dolby E, even thought it's not really a noise reduction system. jhawkinson 03:56, 24 September 2007 (UTC)
thread_title:  Dolby E 

message: The following sentence in the dolby hx section does not make sense:
"With fixed frequency and amplitude high frequency strong signals the amount of bias signal needed is reduced."
What on Earth does that mean?  No really, I can't even guess what is trying to be said in this sentence.
I can't edit the text myself because I have absolutely no clue what was supposed to be intended by this sentence.  I don't think it's simply a case of missing punctuation - it's absolute gibberish.
I hope someone can rewrite it,
Thanks
Daniel  —Preceding unsigned comment added by Dpolwarth (talk • contribs) 23:10, 17 April 2008 (UTC)
replies: text: I fixed the sentence, but the entire article needs copyediting. I'll try to get to that later today, but I'm wondering whether the HX section really shouldn't have its own article. The article, which is misnamed in the first place because it's about systems (plural), has "noise reduction" in the title. Although HX and HX Pro can boost the S/N ratio slightly, they are not NR systems per se. Rivertorch (talk) 23:48, 17 April 2008 (UTC)

text: Agreed to an extent. Dolby HX Pro isn't a noise reduction system, but it does help any 'flavour' of Dolby NR to track more accurately on playback, so I've amended the section accordingly. Although it's difficult to find any supporting citations, it's an inevitable consequence of the improved amplitude linearity that HX Pro brings to the tape itself during the recording phase. This effect is particularly noticeable (and very easily measurable) when trying to calibrate Dolby C on a non-HX Pro deck versus an HX Pro deck. All else being equal, an HX Pro deck will always outperform one without it in this respect, particularly when using Type-I or Type-II tapes. Gruntsplat (talk) 13:09, 14 December 2016 (UTC)

text: Yes, HX Pro probably deserves its own article. (Fwiw, while HX Pro isn't a noise reduction system per se, it does improve the S/N ratio by permitting higher recording levels.) Rivertorch (talk) 15:58, 2 April 2010 (UTC)
thread_title:  Dolby HX Pro description - there is a sentence that does not make sense 

message: About 25 years ago when as the engineer for a radio station, I read an article in a technical magazine on the history of the Dolby noise reduction system. It mentioned that the reason why the Doors 1st record has such a bright high end sound is that the Dolby playback settings were accidentally not turned on after the tapes had been encoded. The explanation given was that it was new technology at the time and a secondary recording engineer was not familiar with it. Timeline wise this seems plausible. Has anyone found any verification of this?22yearswothanks (talk) 02:43, 21 March 2010 (UTC)
thread_title:  Dolby A 

message: It is premature to say that analog recording is obsolete. Even some CDs are going back to analog remastering to try to improve their sound. Our latest auditions of music on Bluyray, mainly concert videos, indicate that there is still a wide gap between the actual music produced by real instruments and the digitally recorded rendition of these.  Analog is still the most capable of the trueist reproduction of the music dynamics and spatial dimensionality, discounting the high SNR possible with digital recordings. Digital is mainly preferred for its convenience.(207.35.47.66 (talk) 00:01, 23 March 2011 (UTC)
replies: text: The current version reads; In other words, Dolby NR is not becoming obsolete for analog recording, but analog recording itself is less prevalent as digital recording has become more widespread. This seems quite reasonable and factual without being POV or OR, regardless of one's opinion. Ubcule (talk) 12:29, 4 September 2013 (UTC)
replies: text:  The above cited current version surprised me when I got to the end of it and saw that its neutrality was questioned. I thought it was a very fair statement. Yes, some analog recording is still being done, but the mainstream uses of Dolby have more or less evaporated. Also, the people using analog tape are most often the die-hard purists many of whom did not embrace any noise reduction system to begin with. So, I think it is a fair statement. Rlhess (talk) 21:33, 22 April 2015 (UTC)

text:  In reply to immediately above: That depends on a person's definition of "die-hard purists". True audiophiles nearly always embraced Dolby B and C as they'd usually have decks of sufficiently high quality for both to work entirely correctly thus improving the perceptual transparency of the medium. The improvement with Dolby C arguably brought cassette very close to CD-quality at sensible listening volumes with 20dB of noise reduction along with greatly extended reproducible frequency range at normal recording levels with the aid of spectral skewing. 20Hz to 20kHz (+/- 0.5dB) at 0dB record/playback level is a reality on some high-end cassette decks with Dolby C even with budget Type-II tapes. Nearly all of those who've ever complained about Dolby B or C colouring the sound in some way either haven't heard it working properly or have used suspect testing methodology. The problem of poorly performing decks crippling noise reduction transparency was the reason for Dolby themselves insisting that any deck to be installed with Dolby S must pass their own tests for meeting certain minimum performance criteria. GIGO. Gruntsplat (talk) 13:11, 13 December 2016 (UTC)

text:  The neutrality of the claim made on this talk page of 'analog superiority' is also in dispute. Blind controlled studies where the listener has no knowledge of the actual sound source have proven time after time that current digital technology, when inserted into a channel, is audibly transparent compared to a single straight analog channel when playing a live performance in an isolated room at comfortable listening levels (actually the studies proved this with CD-audio digital technology that is 'inferior' to current technology). Claim of 'analog superiority' is only encyclopedic in the analog-vs-digital article on the (dying) controversy and is now widely recognized as fallacious.CherylJosie (talk) 20:56, 4 November 2013 (UTC)
thread_title:  Neutrality disputed tag 

message: The Dolby C section refers to audio 'spectral skewing' but links to a Wikipedia article on gas chromatography where spectral skewing refers to the change in detected mass spectrum due to the destruction of some (lighter?) components from the ionization(?) process. I suspect there may be another form of 'spectral skewing' that refers to audio spectrum or some similar term such as 'spectral masking' etc. but the link to mass spectrometry is obviously wrong. Does anyone know what the correct technical explanation is?
CherylJosie (talk) 20:01, 4 November 2013 (UTC)
replies: text: I removed the offending bit because the entire sentence was opaque and baffling. It was supposed to be informing the reader about the technical basis for Dolby C but it revealed nothing and just caused more questions. Binksternet (talk) 20:54, 4 November 2013 (UTC)
replies: text: Spectral skewing was part of Dolby SR for professional use, not for Dolby C. 89.204.155.163 (talk) 03:27, 26 October 2015 (UTC)
replies: text:  The above statement is false. Spectral skewing is part of Dolby C and always has been. A quick read of any of the freely available datasheets for Dolby B-C NR devices makes this perfectly clear. Please check reputable sources to confirm statements before claiming them to be fact. http://pdf.eepw.com.cn/b20090813/c663b0b606cffaf599bdb0afa2a0ce6b.pdf Gruntsplat (talk) 12:00, 13 December 2016 (UTC)
thread_title: 'Spectral Skewing'??

message: Hello fellow Wikipedians,
I have just added archive links to  on Dolby noise-reduction system. Please take a moment to review my edit. If necessary, add  after the link to keep me from modifying it. Alternatively, you can add  to keep me off the page altogether. I made the following changes:
*Added archive https://web.archive.org/20121002034259/http://www.dolby.com/uploadedFiles/English_(US)/Professional/Technical_Library/Technologies/Dolby_Spectral_Recording_(SR)/33_SpectralRecordingPaper.pdf to http://www.dolby.com/uploadedFiles/English_(US)/Professional/Technical_Library/Technologies/Dolby_Spectral_Recording_(SR)/33_SpectralRecordingPaper.pdf
*Added archive https://web.archive.org/20121021010816/http://www.dolby.com:80/uploadedFiles/English_(US)/Professional/Technical_Library/Technologies/Dolby_A-type_NR/212_Dolby_B,_C_and_S_Noise_Reduction_Systems.pdf to http://www.dolby.com/uploadedFiles/English_(US)/Professional/Technical_Library/Technologies/Dolby_A-type_NR/212_Dolby_B,_C_and_S_Noise_Reduction_Systems.pdf
When you have finished reviewing my changes, please set the checked parameter below to true to let others know.
Cheers. —cyberbot IITalk to my owner:Online 04:55, 29 August 2015 (UTC)
thread_title:  External links modified 

message: This article covers an extremely important area of audio technology and it has very poor references. The "How Dolby NR works", "Dolby A", "Dolby C", and the "Dolby B" sections are completely unreferenced, save for the description of Dolby FM in the latter! 
As  notes above nearly all of the references are going to be found not online, because they predate the Internet. We may however have an "out" in the amazing collection of electronics magazines at http://www.americanradiohistory.com/ It has been OCRd and so is text searchable, although the OCR is often inaccurate, the actual scans are available on the site as well. 
n.b.: I will help format references using the cite, etc., templates, if the raw data is provided. Jeh (talk) 20:13, 15 December 2016 (UTC)
thread_title:  References 

message: Understanding this subject would be helped with appropriate graphics- equalization curves, even circuit diagrams.
Public-use graphics might be found in the various patent documents, if no one has the capability to re-do copyrighted drawings.
71.230.16.111 (talk) 22:33, 10 June 2020 (UTC)
thread_title:  Graphics needed