What is Dolby Noise Reduction? Dolby's Humble Beginning technology connections

Frate, de unde ai gasit camasa aia? Nu se mai poarta de 15 ani. Acum se poarta slim (cambrat). Esti tanar. Poartat haine pt varsta ta… daca vrei sa dai bine pe sticla (ecran). Arati ca si cum te-ai imbracat cu hainele bunicului. Un inginer trebuie sa stie pe ce lume traieste. Sa aiba simtul realitatii.

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Their First Product

A simpler form of this, pre-emphasis, was also commonly used on LPs to reduce high frequency noise. You could probably do multiple videos on the format wars around LP equalization curves and pre-emphasis, but it eventually settled out with a standardized "RIAA curve". CD later included a pre-emphasis option as a workaround for high frequency quantization noise caused by early encoders and poor playback equipment, but it was inconsistently implemented and rarely used. Speaking of which, if you haven't done a video on HDCD and how it revolutionized CD premastering, that's definitely a worthy topic.

Dolby invariably sounded horrible, cutting off a lot of the sounds between transients and sometimes giving a weird muffled underwater vibe depending on the dynamics of the music and the volume at any particular time. Often it was more comfortable just to reduce the treble to compensate for the boosted high frequencies on a Dolby encoded cassette. In the days of Walkmans there was never a completely satisfactory sound quality from cassettes in my experience

Noise reduction is also why some old recordings with low budget recording followed by low budget digital transfers sound terrible. A lot of old bluegrass (and I assume other niche musical styles) was recorded without any noise reduction reduction, but the digital "remasters" are sloppy with the stuff. I often just boost the treble on them until I hear enough hiss to make the music sound right. I wish there were better tape transfers of a lot of these classic albums. Of course there are also occasionally albums transferred without the RIAA curve. I wish Dolby would write a software plug in to add/remove noise reduction in a daw so some of these old transfers could be fixed.

Although your explanation was pretty well spot on, the reality of living with cassette tapes was quite different at the time. Dolby wasn't by any means ubiquitous in all playback equipment, and even when it was there it was largely ignored. This might have been because the end result was never really what you would have expected from an untouched recording. Many people, myself included, just ignored the Dolby to what extent was possible. Some friends and I actually did some digging, and found that the whole noise reduction process was highly dependent on the tape itself, as well as the calibration of the electronics. What we found was that the best you could expect on any given playback machine was for the response curve to be more or less correct only for one oxide formulation. In later days, tape quality improved dramatically, and so did output level. This meant that because of the much higher output for the same recording level, the noise floor was automatically lowered to produce much better noise performance without using the Dolby at all than it was previously with it. The upshot is that millions of recordings were made with built-in distortion, which couldn't really be fixed. Living with this situation caused a smouldering resentment among those who were sufficiently aware, although much of the listening public had no idea anything was wrong, and anyway, so much of the commonly used equipment either didn't have Dolby or the user just ignored it. In later days, tape formulation had improved so much that an unadulterated recording was almost indistinguishable from a CD. The end result was that we got decades of ruined cassette recordings for no good reason. Dolby made tons of money and ended up in the undeserved position of being the default audio codec when the DVD came along.

Taking everything into account, including hindsight, having cassette tapes as your normal means of consuming music was a decidedly disappointing experience. So, the Dolby Distortion was only a relatively small component of the unhappy situation. People today have no idea how lucky they are.

0:42

That flashed message at 0:41 says "Say 'Their First Product' one more time, I dare you". It took me way too many tries to pause it on time.

Dolby A didn't go over too well because many people held the opinion that it tended to give things a "harsh" sound. Part of this, I think, is probably a misunderstanding of how to utilize the system. I admit that as a young kid, I never liked the sound of Dolby but then I never had quality equipment to listen on and since "brighter" tends to sound better in many cases, I only rarely used my boom box's Dolby processor, not fully comprehending what it was trying to do.

One fun fact is that the Dolby boost did some interesting things that engineers sometimes decided to take advantage of during mix down. So as a way to give lift to some sounds, they'd be run through the Dolby boost and then mixed into the recording as they were.

Audio SNR is still an issue but mostly only within the recording studio and there the issue is microphone sensitivity vs the source relative to ambient noise and self-noise from any outboard equipment processing the sound. (Like turning a speaker way up with no signal. The "hissing" sound is the self-noise of the amplifier.)

I actually like that noise !

Not sure if you have already done this and I have somehow missed it, but I would like to see new microphones versus older microphones (the ones they use to look good in films of a certain age!!!) Love your stuff, Thank you

amazing bow tie, love your channel

The text at 0:41–0:42 was only there for 2 to 4 frames.

More like, "Dolby's HUMble Beginning".

5:49 damnnnn that's good

“You can’t make a rock album in Dobly!”

Dolby B only operated in the high frequency range. As most of the noticeable tape noise was in this range, it allowed the system to still be reasonably effective.

"The Dolby chip inside the cassette player…" No, my friend, true Dolby NR was implemented with discrete transistors. Today, you systematically reach for the word "chip" to represent electronic circuits. In 1974, analog (audio) integrated circuits, although very complex and useful, were still in their infancy, and did not have as good a noise performance as discrete transistors. I have 2 cassette decks from the 1970' + 80's. A Sansui, and a Pioneer ( the Pioneer with the Omega tuning fork logo, not the new Chinese Pioneer crapany). Both have discrete transistor circuitry exclusively on the PC boards ( and it's a LOT of circuitry). Integrated circuits that could surpass discrete performance in noise and distortion didn't come to market until after 2000. And by then, virtually all audio component manufacturers had moved over to digital due to digital's inherent ability to reduce/remove noise and distortion, as well as to the efficiency and low cost of automated surface-mount PCB fabrication, virtually all of which is done in China.

Maybe it's because I was a kid when Dolby noise reduction became common, and because kids love treble, but I never liked how music sounded with Dolby turned on. To me the hiss in the background of a cassette was a bit like the paper on an easel before the paint/music was added to it. The hiss sort of provided a reference point to let you know how intense the sounds of some songs were compared to others. Or at least that's how my adolescent brain analyzed it. I probably just wanted more treble.

This is my favorite video of yours! lol

Their first product

Single frame text. Slick devil.