Did that Dolby thing ever work?
ERRATUM
I gave the width of cassette tape as an eighth of an inch, which is probably too much of an approximation. It should be 0.15 inches. Wikipedia states "The tape in a compact audio cassette is nominally ⅛ inch but actually slightly wider (3.81 millimetres (0.150 in))" DM
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Thursday April 20, 2023
David Mellor
David Mellor is CEO and Course Director of Audio Masterclass. David has designed courses in audio education and training since 1986 and is the publisher and principal writer of Adventures In Audio.
@SeanMcKinnon-p3z: A-Type was used in Cinema amongst other uses mostly on optical tracks but also on 6 track magnetic.
@JacGoudsmit: It's amazing how much we all used to know that now nobody remembers, even if they were there. I had a good quality cassette deck with Dolby from the time when I was 15, and I knew exactly how it worked, and that you had to use it at recording time as well as playback. I also had a portable cassette player with Dolby at some time and I left it switched off on purpose because I had crappy headphones and that way my tapes sounded better on the bus.
@0525ohhwell: I just started getting in to some nostalgia so I have an old walkman that is the same model I had in High School (wm-f2805). I also have a Marantz PMD510 2 head deck with that sorta annoying head flip mechanism for the auto-reverse. I gave up trying to record with Dolby B and having it sound good on the old mid-range walkman that I rather doubt I can do any head adjustments on. It is better than a few pre-recorded cassettes I found laying around with Dolby B though.
If I record without Dolby, it sounds surprisingly decent so I am just going to stick with that. If I was playing back on the same deck I record on then yeah, I would certainly go Dolby C. But for home listening, I prefer to stay full digital really.
@Harish588: Demagnetization of head is not record for a 2 head decks. If you record tapes regularly then the tape heads gets demagnetized automatically. For a 3 head deck where record and playback heads are different you will require demagnetizer.
@Kylefassbinderful: Personally I never gave Dolby a chance back when I was a kid in the 90s because:
a) Tape hiss never really bothered me all that much
b) Most of the time I listened to music on my cheap knockoff walkman that had no dolby
c) I usually recorded rock/punk/rap from vinyl and I always recorded hot on type ii/iv tapes. I used to get free tapes from my step dad all the time.
Thirty some odd years later and I make/listen to my own mix tapes in Dolby S and sometimes VHS hifi.
@charleshollingsworth1583: Dolby got rich by making a tone control potentiometer a push button or a slide switch.. I have owned all kinds of high end audio equipment including a nacamichi dragon and always left the noise reduction off on recording and playback. Was the nac that great, nope it was sent off 6 times the 1st year i had it from new. After the warranty was gone it still stayed fkked up. Sold it and went with an akai don't remember the mosel but it was fantastic. I was at a high end stereo shop in atlanta, ga years ago making a expensive purchase on tannoy speakers and whilt chatting with their over paid high end guru i told him what i thought about dolby and i told him hey i can do the same with my rane equalizers and he agreed poor man's dolby. Like the song states it's all about the bass NO TREBEL, and the back ground tape hiss guess what it's still there.
@ThePlumbum1: I leave it off. I use type II Maxell tapes with a 1970’s superscope tape deck . Record and playback on the same deck. Sounds great.
@dakota-sessions: Brilliant!
@HAIL_LILITH: Absolutely shite...dolby is crap!
@RoelonLaumen: I used to record on dolby C on Metal and Chrome cassettes, and while playing back I switched it off. this sounded like a broadcast sound processor.
@DelinquentSquirrel: Old video I know, but...
Best performance I've ever had from cassette was using a Type IV (Metal) TDK MA-90 on a dual capstan Dolby S deck. It was difficult to tell the difference between the original CD and the recording.
Then I bought a minidisc deck. Which (at least on the kit I had at the time) sounded identical to my ears. Any original recordings I made on MD are quickly transferrable onto a recordable CD via the digital output, and unlike cassettes, minidiscs don't deteriorate with age.
@UXXV: I always thought people left Dolby off as they preferred the boosted treble
@AudioMasterclass replies to @UXXV: They did, to compensate for the fact they never cleaned the heads.
@UXXV replies to @UXXV: @ a year plus old video and you still took time to respond. Kudos to you fella! Only just found your channel recently and loving the content!
@80sGuy.: Thomas Dolby told me differently, and said we're blinded by science.
@duprie37: As a kid I only had cheap boomboxes so I never used Dolby. Nowadays it generally works fine with quality tape (Type II, IV) recorded at the indicated level for Dolby NR. But at that point it's not even useful. If I use cassettes it's mostly to listen to popular music where there isn't enough dynamic range to require noise reduction anyway, because the signal is loud enough to mask almost all noise. I can only see it being useful with classical and jazz music - eg part one of Ravel's Bolero - but I'd never listen to those styles using cassette, certainly not in 2024. It was awful with most commercial cassettes because, well, commercial cassettes were generally shite in every way: levels were way too low for Dolby except for WEA's Cobalt "Hi Tech" series from 1984-88 or so of which I still have quite a few, where they pumped the levels high.
@MrSlipstreem: I never understood other people's complaints about Dolby B not working correctly until I bought a deck where it didn't. It had been incorrectly calibrated at the factory. Thankfully, I've always had access to a signal generator and an oscilloscope and was familiar with what the correct levels should be for the specific Dolby ICs.
The biggest problem with Dolby B was that it was often deployed on cheap cassette decks with a shockingly poor high frequency response. Using Dolby B correctly would magnify this problem. It actually worked very well indeed when correctly calibrated on well maintained decks with a reasonably flat frequency response.
I've never owned a hi-fi cassette deck that wasn't flat within a dB or so up to at least 16kHz with a ferric tape, so it's not something I've ever had to deal with personally.
@fred321cba: I'm trying to send this YouTube link to me in the 1980s. It's not working. Is anyone else having this problem?
@AudioMasterclass replies to @fred321cba: The problem, all the way from the 1970s to today, is that people are entrenched in their beliefs. People who don't clean, demagnetise or align their machines will blame any problems on Dolby when it's the lack of care that's the problem. People who do look after their machines will generally say that Dolby is OK, and it certainly does reduce noise. But there's another group who just like the extra brightness when a Dolby-encoded tape is played with the Dolby switched off. There's no hope for them.
@ReachForTheSkyVideo: Stopped watching and gave this the thumbs down as soon as your "technical assistant" appeared.
@ninaevans4501: To be honest, how about "adaptable dolby", in other terms "dolby with BRAINS". To be fair, most of us simply don't have the time to worry about cleaning our cassette deck heads pinch rollers, capstan, belt tensions from motor to deck, vibration levels from motor to deck. That the cassette brand has to be the same manufacturer as the deck and amplifier.
No wonder most people dislike Dolby. Can you wonder now, why folk would much rather have digital, and sling their vinyl records and cassette tapes in the bin?
@florian5900: I never use Dolby B. The tapes sound different on every deck an they sound especially dull in my car. I can live with the hiss when recorded/played without Dolby B
@martyjewell5683: Yeah, there was Dolby-B and C. Later came a Dolby-S(?) And then JVC had a different system "compatible" with Dolby (or so they said) called Super ANRS. Also in the 1980's came Dolby FM. Supposedly to "fix" FM broadcasts like Dolby-B worked on cassette tape. My Onkyo TA-630D deck had a built-in Dolby FM decoder. Sadly, Dolby FM never caught on. I have found that using an expander (Pioneer RG-2) with the tape format helped with noise reduction and dynamic range. I use the RG-2 whenever I play cassettes or open reel tape. Very informative video, thanks.
@petrsittek1021: I used regularly type C dolby in Denon DRM 710 without any issues.Even use headphones for critical listening no problem hiss is out
@AudioMasterclass replies to @petrsittek1021: My Fostex E16 worked brilliantly with Type C. Correctly aligned, heads clean - nothing to go wrong.
@jonfoss3437: It dulled the music
@scytube: Basically a helpful video, but I completely tuned out when the "AI" started talking.
@stevenpotts3056: Loved the video, and your technical assistant as well. If only I could find a gal as interested in audio as "she" is!!!! I'd be in heaven!!! I have sworn by the Dolby System since 1981, when I bought my first real cassette deck, a Pioneer CT-950, which had only Dolby B (no HX Pro at that time, however, I am an even bigger fan of the HX Pro extension). I have always found Dolby B to work exceptionally well when I did the following : a) I always used name brand blank tapes, Maxell and TDK (Sony if in a pinch); b) kept the heads and all the mechanical goodies cleaned DAILY with 91 to 95% Isopropyl alcohol; and, c) kept as tight a position on my recording levels as possible, keeping the absolute peak-levels at 3db over the zero reference (normal bias) and 4db (chrome) and 5db (metal). I am still playing tapes that I recorded 40 years ago, and they still sound superb, yes, with Dolby B switched on. The thing most people need to remember (me included sometimes) is that some pre-recorded tapes can sound muddy with Dolby on, especially pre-recorded cassettes from the early to mid 1970's. I can only think of one company at that time here in the US that encoded their pre-recorded tapes with Dolby, and that was Columbia Records and their family of assorted labels (like Epic, and so on), because they tended to use not-so-good quality of blank cassettes for the mass-production of their product. Plus, the basic ferric oxide formulation at that time really needed improving (most people still thought of cassettes at that time as dictation machines and tape-recorders, not intended for serious music listening), which came along later in the 1970's. Like you said, none of that is not the fault of the Dolby System, but of the inherent limitations of the product by the producers (initially) and, the complacency and lack of care by the consumer (eventually). It's a shame that licensing was lost for all future decks of "quality" to be made in the future (I say this tongue-in-cheek, as most all new, if not all new, cassette decks are pretty much pieces of crap, and no amount of any kinds of "Systems" can make them sound good). Keep up the good work, and if you can, maybe do a video (if you think it's worth your time to do so) on Dolby HX Pro. Thanks again!!!!
@mrnmrn1: My experience with Dolby: about half of the pre-recorded cassettes sound awful with Dolby switched on, because they were duplicated with bad calibration. The other half sounds excellent. Dolby S is simply fantastic, it removes practically all the noise - takes some fine details with it, but not as much as Dolby B. The problem with Dolby S is lack of compatibility. Very few decks support Dolby S, and while you can listen to a Dolby B encoded cassette without Dolby switched on, it is impossible with Dolby S, it sounds unbearable without decoding.
@Samsgarden: Dolby’s kinda like the remastering wank. Everybody wants something better and is never satisfied.
@michaelgreene5703: why do you care you are against cassettes and decks....end of story??!!
@2visiondigital: No.
@AudioMasterclass replies to @2visiondigital: Now if you could have given a reason why you disagree with my video, that might have been a bit more interesting.
@2visiondigital replies to @2visiondigital: Yes. I have numerous high-end decks using the best tapes. I rather have the noise floor of hiss rather than the shaved off highs. Dolby B,C,S did not work for me. DBX a little bit, but mostly only on the deck they were made on, so not very compatible overall. For me a good machine, good tapes, no noise reduction is what I preferred.
@robertoney5665: Audiophiles are overrated, followers or wannabes.
@ThomasTVP: Dolby S did a lot to improve the higher frequencies in consumer-level tape decks. That one really worked.
@stevenclarke5606: I saw a documentary about Dolby Noise reduction, and in the 60’s when Type A was being sold to professional recording studios, they cost about £10,000 which is still a large amount of money, but back in the 60’s semi detached 3 bedroom houses cost about £2000 .
@AudioMasterclass replies to @stevenclarke5606: Worth it though. Do you have a link?
@stevenclarke5606 replies to @stevenclarke5606: @@AudioMasterclass no sorry it was a few years ago
@noorsheikh8739: Another solution to the issue, in my experience, is to start recording on chrome tapes without dolby. I am just a novice, not a master.
@chotunab: Some times I like it switched off and sometimes I like it switched on, but I learned a lot after the explanation about how the system works, thanks for that
@GTI1dasOriginal: Not going into the Rabbit hole of debate, but... By experience I can say this: IF a good deck is adjusted perfectly, dolby B does work as intended and designed. I have had various decks which I adjusted like they should. Prerecorded cassettes with a dolby logo however.. is a different story. They WILL not sound good with dolby switched on.
@AudioMasterclass replies to @GTI1dasOriginal: This could be compared with (analogue) Dolby Stereo in the cinema. It sounded fantastic in a Dolby-equipped cinema (like when I saw Star Wars in the Odeon Marble Arch https://en.wikipedia.org/wiki/Odeon_Marble_Arch in 1978), but it also sounded good in a cinema without Dolby. In fact probably better than a print not Dolby encoded. I tried to see Close Encounters on the same day in Leicester Square https://en.wikipedia.org/wiki/Odeon_Luxe_Leicester_Square but I couldn't get in.
@Mr_Meowingtons: Dolby B sucks C was beater. S and DBX where good.
@steffenbrix: I work daily on cassette decks as a nostalgic hobby on the side of my musician life - and have used tapes since the 80s.
Dolby C and S are pretty fantastic if you have a clean and well calibrated machine. I use those Dolby types everyday.... never bothered with B.
But all the old prerecorded cassettes with Dolby B do not work with Dolby today! They are better without!
@clippy8430: Sorry, but your "technical assistant" is annoying. Couldn't watch this video through, which is a shame because I'm sure it had useful info. Speak it yourself mate. Fire the "technical assistant" and "her" annoying voice and image.
@AudioMasterclass replies to @clippy8430: You're going to have to find a different channel to watch, my friend.
@clippy8430 replies to @clippy8430: @@AudioMasterclass will do. Cheers.
@phaenius: Why you didn't mention Dolby C and Dolby S?
@AudioMasterclass replies to @phaenius: Too complicated for people who don't understand Type B.
@quebecforce111: I like so much NR dolby C on for recording on my Nakamichi DR-3
@johnviera3884: it was a failure. it’s way too complicated for a mass consumer product.
They should’ve just implemented it on high end hi-fi gear.
@AudioMasterclass replies to @johnviera3884: Eh wot? It had one switch.
@johnviera3884 replies to @johnviera3884: @@AudioMasterclass The one switch which consumers unanimously dubbed “the mud button”
leave it off.
@johnviera3884 replies to @johnviera3884: @@AudioMasterclass I actually think the failure was because of the fact that if you give listeners an option between more treble or less trouble in an A/B live audio example they always pick that “Airy” frequency response.
if you already hear the high end boost and your ears adapt to it once you take it out it sounds like a drop off. Even though psychologically if the button would’ve been pushed in from the beginning and you never heard the other example you would be fine and think it sounds normal
@AudioMasterclass replies to @johnviera3884: You're not wrong.@@johnviera3884
@TheHSIHP: When i hit the dolby button, the cassette always sounds way muffled.
@AdmiringGoBoard-jw8cz: These things could have been taught to fifth graders in one or two classes rather than talk about last week's world series game
@Synthematix: Tape is noisy and vinyl is even worse
@paulstubbs7678: That was my experience with my Teac CX-270 cassette deck, yes Dolby did take the top off the inter track noise, however it did the same to the music - it was not backing off as you describe, so as I usually listen to the music, not the inter song noise, I tended to run with it off.
I did try it on quite a few occasions, but tended to think it didn't work very well at all.
Very high end cassette decks did have the ability to calibrate themselves to the tape you were using, however your average HiFi gear did not offer anything beyond the two position bias and eq switches that one blindly set according to the tape type in use.
For the most part I only used cassette tapes for playback on portable gear that had no switches, with their highlight being stereo rather than mono. So my Teac was basically only used for recording, for playback/listening I used an open reel machine (later on using a HiFi VCR), before moving over to CD's
I never thought cassette's were up to HiFi, well not the ones I could afford.
I'd record a record/LP/vinyl onto a cassette, then compare the playback, dolby off was almost always closer to the original.
@Mikexception replies to @paulstubbs7678: It was not emphased here but head condition has a lot to do with good dolby results Head which is visibly worn works in playback almost as good as new and if contact is ok then sounding appears to be by ear no problem. But when is worn the voltage level on head is lowered and it already makes deficiency making too quick brink of action in Dolby. .
For some advanced users there is option. My deck head has some delicate wear and I noticed Doby operation dull but only in one channel - other was adequate to original . Heads are worn never identicaly or may be after 45 years coal potentiometer got misaligned ? . . I found the potentiometer on electronic plate which governs that Dolby level and adjusted it - it came out to be some 6% difference and both are now exact and good. But it is for advanced who will not mistakenly turn and misadjust other simmilar pots which will require even more experience to return ( I realigned after 45 years almost all because it was broken no reparable deck probably from service spares. )
@AudioMasterclass replies to @paulstubbs7678: @Mikexception Oddly, I was never troubled by head wear on any of my cassette decks including my Portastudio but this may be because of the masking effect of low expectations. On the other hand, my Fostex E16 16-track reel-to-reel - did I give it one relap or two before I went ADAT to experience other delightful kinds of problems? As for delving inside my cassette deck to align levels, I too can wear that t-shirt proudly.
@stevenjackson8226: It did work, and well, but it was work to make it work. The whole compact cassette thing was fiddly and ultimately limited. Yes, transport hygiene was critical, and some machines had extensive calibration features. I had some Nakamichi decks, and was familiar with other decks, that had extensive manual or automatic calibration capabilities, and things like outboard Dolby B or C boxes. To optimize recording and playback, these things had to be continually optimized. Then, a tape was pretty much optimized for that machine it was made on. Play that tape on any other machine and it almost invariably sound different, and usually worse.
@JohnnyFocal: Your on a role. Another good video!
@TWEAKER01: If the tape machine's heads are clean and aligned properly, of course Dobly NR just works: correct frequency response and tape hiss is reduced. But especially if recorded and played back on the same deck. The trouble was recording on a decent deck then playing back on another (and car players without Dobly) – people got used to thinking the over-bright, compressed HF (and hiss) was normal.
In fact, "dolby stretching" (encoding and not decoding) was often used in multi-track tape recording as an enhancer effect on parts such as backing vocals.
@rabb1tjones921: I bought a prerecorded cassette, back in the day, that was recorded with Dolby noise reduction. I also used to use a little screw driver to align my head for different tapes.
@anahatamelodeon: In a test where Dolby recordings were played back to a panel of listeners with good equipment perfectly set up, and compared with recording and playback with no Dolby, the noise reduced recordings still sounded subjectively duller, even though the frequency response could be measured and was exactly the same. A further experiment explained this: they played a recording back with and without white noise deliberately added, and everybody agreed that the sound with artificially added white noise sounded "brighter". So even with perfect aligned equipment you can't win!
Professional Dolby type A recordings (e.g. studio mixes and master tapes) always featured a burst of "Dolby tone" at the beginning of the tape: this was used to calibrate the playback level so playback processing would be matched to the record processing. I think some Dolby B recordings also had a Dolby tone at the start, but VERY few cassette players had anything you could adjust to use it, and virtually nobody would have known how to use it or even what it was.
@Mikexception replies to @anahatamelodeon: That is another perfect confusion -listener's impression depends on spectrum he at moment hear. Today I make recordings from my exceptional AM radio and I observe that whenever reception is more noisy ( noise spectrum is almost two times wider than signal from station) my impression is that such recording is.... like I listen to wider spectrum. When day is good for reception and noise is not much noticeable impression about sopranos is more confusing - depends on instrumentation and track. . .
@IncognitoChild: It's funny how long each iteration of Dolby took to filter through into mainstream home audio decks.
When you consider Dolby B was introduced in 68, Dolby C in 80 and Dolby at S in 98. Yet I didn't see too many decks with Dolby C and until the mid to late 80s. It felt like Dolby S take up was much quicker although it may just have been that I was at a working age to be able to afford higher priced electronics.
For the kind of music I listen to I used DBX instead..... But for compatibility in Walkman's I used Dolby B and Dolby C.
@donmason356: Dolby B and C helped out great when recording my scratchy albums to cassette. Love cassettes and still record off radio and turn table. Just need some power to drive them.
@MrCandude: Dolby shmolby. A fad gimmick. Otherwise we would have had the button on CD players and streaming services.
🤓
@TWEAKER01 replies to @MrCandude: CD (and early digital ) had pre-emphasis and de-emphasis, to help suppress HF noise on playback. It was actually an analog circuit in the converter, activated by a sub-code flag on the disc or digital tape.
@MrCandude replies to @MrCandude: @@TWEAKER01 Was there for the beginning of CD. Did not know about the emphasis button. Cool. Thanks!
@PHX-222: Using the right tape and keeping your heads clean is essential, but that's just part of the equation.
The reason why Dolby B failed to decode properly in most decks and portable players was head to tape alignment, or azimuth. Cassettes can play perceivably fine with some minor mis-alignment of the tape as there is a bit of tolerance for mis-tracking. Unfortunately, however, when the audio signal is encoded with Dolby, this tolerance diminishes greatly and so therefore, unless the tracking is pretty much dead-on, Dolby B will not be decoded properly and usually results in the loss of highs and a muffled, lifeless sound.
Pre-recorded cassettes were the worst for this, which is why most people thought the tape sounded better with the Dolby switched off. So because of this, the consumer would NEVER turn Dolby on for recording on their own decks. Which was a shame because if they did, they'd discover that:
If you played back a tape encoded with Dolby on the same unit that made the recording and encoded the Dolby signal, it worked perfectly, with no issues. Why? Because it's tracking dead on!
Of course, if you're using shit tape and not cleaning your heads, it's not going to work then either. :)
@TWEAKER01 replies to @PHX-222: Absolutely correct, particularly as Dolby NR calibration was so level sensitive. As was Dolby A and SR on pro machines.
@jokubrik6597: In my younger days I always avoided Dolby, like many others, as it seemed to lose some high end signal/sparkle. Now recently rediscovering cassettes at the age of 60, I am using it on all the time and not having any issues. The recordings sound pristine to me! -I probably put it down to the loss of high frequencies that we all experience to whatever degree as we age. Just a thought...
@Mikexception replies to @jokubrik6597: In old times listeners accpted loss of sopranos during recording as normal ( digital was not known) and were delighted with any possibility to regain them - with dolby off and tone controls and "crispy speakers" Tapes were cheap, heads dirty and decks not aligned by producers as should/ misaligned . Any upbeat was welcomed - unfortunately together with noise (like the solution with switched off Dolby). . Today thanks to higher demands from listeners, and better knowledge, years of experience . we can avoid it and forget about noise reduction too
@schlechtj1: I have seen YouTube videos on dolby and they just put in a cassette and try the different settings. "Wow dolby c sounds bad". I have to tell these reviewers that it must be encoded and then decoded, you just can't flip the switches willy nilly. These are people who claim they know what they are doing so I can see most people's confusion.
@enricoself2256: I think Dolby B - or better, playing tapes encoded with Dolby B without Dolby ON - is partly responsible for how some music recorded in the 80's sounds: several digital recording's from mid 80's have very prominent treble, like playing a cassette without Dolby. Recordings from the 70's or 90's are not so much treble rich. Might be a coincidence, though.
As for Dolby, I actually only used Dolby B on type I cassette; type II and IV are better off without Dolby, the 70us eq is enough to remove tape hiss. Dolby C depends too much on tape deck calibration, frequency response and ability of the tape to retain recorded levels (some type II tapes lose 1 ~ 2 dB of levels in the course of some years), so I never ever used it (although it sounded nice on a hi-end revox tape deck)
@Makinthadough: Appreciate your previous response to my precious comment on sibilance. Looks like you’re in a different room that would reinforce your answer that your direction in the previous room was to blame not your gear. Sounds great in this space on the same mid-fi gear on my end. Thanks for another great video.
@DKN808: Nak Dragon w/auto azimuth —problem solved. The issue with Dolby was ALWAYS tapes made on “other” decks, like prerecorded cassettes from record companies. If you recorded and played back tapes on your own deck, Dolby worked fine 99% of the time.
@pedrolima8705: I've just discovered your channel and I'm loving your vídeos. I think that set the 400 Hz level for each kind of tape, clean the heads and capstan, demagnetizing the heads, etc., is part of the analog enchantment. As with overhang angle, anti skating, compatibility of the mass of the arm with the capsule, etc., etc.. The hifi is for the ones who love it. Sorry if my english is incorrect, but I haven't trained it for more than 20 years.
@jeffbranch8072: I don't know if the Dolby button worked particularly, but my Dolby CD's work very well! I especially like 'Europa and the Pirate Twins' from 'The Golden Age of Wireless'. And who can forget 'Aliens Ate My Buick'?
@AudioMasterclass replies to @jeffbranch8072: Comment readers might like to know this refers to Thomas Dolby, a musician popular in the 1980s https://en.wikipedia.org/wiki/Thomas_Dolby
@universalhead: So 99.8 % of tape-decks have mis aligned heads according to this. Every tape deck I have dulls the sound when you turn on Dolby. It gets rid of the hiss which is what I thought it was supposed to do.
I have prerecorded tapes done Dolby HX pro that sound amazing on the same machine with all dolby turned off and very little noise. I record blank tapes from CD or vinyl from the 80’s on type 1 cassettes and it sounds great.
I have other prerecorded tapes that sound dull no matter what you do. I found high quality recordings sound amazing, like some vinyl records sound not good at all and some sound incredible on the same stereo.
@salmorreale7900: Thank you for posting.
@poekiemanpoekieman9224: I used to have an Akai GX31, if I remember correctly, it could adjust itself to the tape by recording beeps and sweeps, playing them back and changing settings until it thought it got it right. It kind of worked.
@devilsoffspring5519: In a nutshell, Dolby noise reduction only works properly if the tape head elevation is adjusted to exactly match the tape you're playing, which it almost never was with pre-recorded tapes or tapes that were recorded on any other tape machine. Turn the tape over to play the other side and you also had to re-adjust it!
When the head alignment is exactly right for the one tape you're playing, Dolby B and C noise reduction were incredibly good--especially Dolby C.
Yeah, cassette tape was pretty noisy format and was never intended for music when it was invented and Dolby NR, either B or C, only worked its magic when the head alignment was just right to give the best treble output. Otherwise, it was awful because it would kill the treble output was well as noise.
@rogerking7258: This is a perfect illustration of how analogue recordings are vastly more dependent on the playback equipment (both quality and condition) than are digital recordings. I've been using cassettes since the 1970s and I have never felt that Dolby was less than excellent; but I've always had an interest in the technology so I wouldn't dream of using a dirty machine, crap tapes, wrong bias, or recording at the wrong level, etc. My current three head machine with Dolby S essentially makes recording that are indistinguishable to the ear from the source, be that vinyl, CD or whatever. However, one thing is certain - pre-recorded tapes almost always sound crap because it would have been too expensive to use decent tape stock or record them at only 1 7/8" speed (+ precise azimuth and probably loads of other factors).
@MrSlipstreem replies to @rogerking7258: Absolutely, and a lot of people will give you the side-eye when you try explaining to them just how good Dolby S was, but in 1989 when Dolby S was launched, Dolby held a listening session for a group of audiophiles (real ones I'm assuming) to compare a digital source with a Dolby S cassette recording. None of them could reliably distinguish one from the other at normal domestic listening levels. Dolby S filtered down to a few mid-tier decks by the mid-90s making it far more affordable for us mere mortals, but the decks still had to meet strict design criteria specified by Dolby in order to receive a licence to incorporate it, ergo, there is no such thing as a bad Dolby S deck.
@FireAngelOfLondon: Nakamichi used to make cassette decks that would adjust their Dolby levels for each brand of tape; you put the tape in and set it to calibrate and it would record a series of tones on the tape and set the Dolby level for recording on that exact tape type. It was a tedious process but was only needed when recording as the levels coming off the tape would be correct if you bothered to calibrate before using a new tape type. Of course if you only ever used one brand of tape then calibration only needed to be done a couple of times a year to get the best out of the machine.
Maybe there were other brands of cassette deck that did this but I never saw one.
@landnnut: The belt on my cira. 1982 Nakamichi BX-1 went bad so b type Dolby is moot.
@Trev0r98: The following is 100% true.
I sped up the tape transport of my 1971-vintage non-Dolby Sony TC-160 cassette deck by a factor of 3 (5.6 ips), rolled back the Equalization (the two outboard pots at the front of the MOSFET-based circuit board), and never looked back.
How did I speed up the tape transport? Simple: I put a couple of Revel car model tires over the drive motor spindle, where the belts went. Then I just wrapped the drive belt around the V-shaped groove where the model tires met. The tires were 3 times the diameter of the OEM spindle.
With this modification, I got around 72 db S/N ratio, and 20 - 22 KHz frequency response on good Maxell cassettes (oddly, not CrO2-based - even though the deck had a CrO2 selector switch) and less than 1% THD at 0 VU, 1 KHz, and .07% wow & flutter.
Of course, a 90 minute cassette was good for only 30 minutes at that recording speed, but damn if this Sony rig didn't sound as good as a Revox A77 reel to reel deck at 15 ips. Only problem was, I had to replace the F&F ("Ferrite and Ferrite") tape heads every 9 months or so, and they weren't cheap back in 1977, when I was 17 years old when I did this. They cost around $30 dollars back then, but were fairly easy to source.
I then boosted the dynamic range - S/N ratio of this deck up to around 105 dB using my SWTP expander/compressor that I put in the signal chain. Very similar to the dbx 119, but in kit form. Yes, I put the compander together myself and calibrated it.
Effectively, I had a 1971 Sony cassette deck making recordings better than any Revox 15" deck (forget about any Nakamichi 1000) and playing back at CD sound quality. Not bad for 1977 - 1978. Five years before CD technology came out.
@howardskeivys4184: Back in the day I had 2 premium cassette decks, one of which was a twin deck. Both units were equipped with Dolby B and C which I used extensively. That was multiple iterations ago of hifi components. Cassette decks no longer have a place in my hifi rig.
We need far more technical information from you. Especially if your technical assistant is going to present it.
@marks42: Agree 100% Dolby B and C work, even my not quite real Dolby C on a Nakamichi 481Z sounded great, but it all needs to be clean and in A1 condition. But in my opinion Dolby B/C is better illustrated with a graph (a picture is worth a….), at school in the 70s, I could always explain it better to class mate’s with graph/diagram. I really love your articles, just good information no BS.👍😊
@ampheat: Despite proper cleaning and demagnetizing, as an owner of multiple cassette decks, the main problem with HF roll off was due to azimuth head misalignment, exacerbated by Dolby encoded tapes.
Had I known this would be an issue at the outset, I would have recorded all my tapes without Dolby. Now the solution is to use decks with adjustable azimuth played back with Dolby.
@zappo7771: Great explanation... so I no doubt broke all logic but... I would record w Dolby B (also thinking my deck had C) and get the saturation as excellent as possible w/o distortion... then in my car the deck had Dolby B as well... but I de-selected the switch and presto the dynamics "seemed" perfect... yes in a pinch you could hear some noise... BUT because of the natural noise floor of the vehical and wind (as w would play Rock as I Rolled) the recorded tape noise was not present perhaps dither??? ... that was as good as it got in the car till CDs ... what are your thoughts?
@AudioMasterclass replies to @zappo7771: Switch Dolby out in a car, or anywhere, brings up low level high frequencies. So you'll hear more clearly above the engine and road noise. DM
@RaineStudio: Leaving Dolby off, even when it works perfectly on playback, is better known as "High-Frequency Hearing Loss Compensation."
@AudioMasterclass replies to @RaineStudio: Well technically you are wrong. But subjectively there is a certain amount of truth in what you say. DM
@Kris_M: I've got 40 TDK and 5 BASF Chrome tapes all recorded with Dolby C and they still sound fine (not dull) today. I do clean the heads and drive parts now and then.
@allanredford6070: good video. imo, subjectively dolby b and s transparenz. the auto-tape calibration n my 90a Sony decks and good factory aignment, bettered mx 80s Nakamichi dcks.. dolby c was poor, audibly odd. few c-equipped production decks met dolby's strict alignment standardsm probably.. my Nakamixhi 700zxe auto.tuning dck+ NR100 v adapter was unsatisfacory. engaginc c on playback of a non-dolby tape is an effecive öpw-pass/high-cut filter for noisy source material, which fortunately, I have virtually none.
xour formidble-sounding lady assistant, looks like fun, if she loosened-up :-)I never experienced dbx I or II. read that it had issues......?
@NackDSP: No, it never worked. That tape deck rolled off the high end so the decoder never got the correct signal level to decode, so the high end roll off was exaggerated by the Dolby expander so the highs were wiped out. The expander had a delay relative to the compressor, so the high frequency transients were squashed. The system never had a chance of working. How could it. The signal used to drive the encoder was lost during encoding and the decode would always be late and wrong. Had Dolby found a way to bury the compressor commands as some sort of inaudible phase modulated tone to drive the expander decode logic it might have had some chance, but it traded dynamic range for a doubling of the frequency response errors and squashing high frequency transient response.
@tennvol2464: The Dolby button was my least fav idea ever! Hated it! Muffled music button.
@Dimster6666: I clearly remember a friend saying "hey that sounds much better" when I switched the Dolby off, being a little perturbed as I am a techno geek and of course if the tape was recorded WITH Dolby so it MUST be played back WITH Dolby! Regardless of how it sounded I would stick to my "geek" guns. Then along came Dolby C and of course metal tapes and being an avid fan of head cleaning, de-magnetizing and correct azimuth & "variable bias" I would spend hours working out which sounded best. I spend so much time on this that I forgot to just sit back and enjoy the music. One day the same friend came over and suggested again I switch the Dolby off, so I did, and very quickly I heard an awkward "nah switch it back on it sounds better!" These days I just log into my TIDAL account, click my mouse and just sit back and enjoy the music - at 66 I no longer feel the need to labour for hours or days getting the right settings - I sit back and enjoy the music, which is what I should have been doing 50 years ago!
@andynaz5631: I thought Thomas Dolby invented Dolby NR when he was blinded by science in that missing submarine.
@Lenny-kt2th: Sounds familiar. I always used Dolby B/C/S when appropriate, but I also know people who left Dolby B off to get a high frequency boost.
@nsfeliz7825: you csn still dolbyize ur tapes today using software. use any daw or audio software that can perform level compression and set it close as possible to dolbay specs whae recording to tape.
@spacemissing: Of course the manufacturers were nice enough to tell us exactly what tapes each machine was set up for....... NOT!
And then, what would happen when you couldn't get the "right" tape any more, provided you Did know what it was?
I didn't have the money to pay for a calibration.
With my TEAC A-170S, I nearly always recorded with Dolby on and played back with it off.
After I bought a Harman/Kardon TD392, if I recorded a tape with Dolby C I normally played it using B.
My Concord HPL-550 car stereo Sometimes gave pretty good results when I used the same
NR setting I had recorded with, but it really depended on the tape and the signal level.
Never got around to testing its dbx function because I didn't have a way to record with that NR.
I still have that unit, fortunately. It sounds amazingy good.
My tapes (I still have all of them) are labelled with the NR used.
A few have the same material on both sides, one with B and one with C.
@johnmason6213: When I was focussed on cassettes in the 80’s it became clear to me that Dolby killed the high frequencies along with the hiss, as a music purist it seemed idiotic unless you just hated hiss more than you loved the full sound. I would put up with the hiss in order to hear all the music.
@AudioMasterclass replies to @johnmason6213: I don't agree with this regarding Dolby, nevertheless it is a useful point. I'm not keen on single-ended noise reduction unless it is really, really necessary. A bit of hiss or a few clicks is often better than messed-about sound. DM
@ianl.9271: Most commercially sold tapes are not encoded. The problem is if someone has heard an encoded program, it will sound brighter when playing back with Dolby off anyway. No one will think that the eq is now wrong because they have not heard the actual source. Brighter always sound better.
Same thing with FM de-emphasis. If it can be defeated, it will 'sound clearer' because of the boosted highs.
@usaturnuranus: I had a cassette deck with dBx encoding and decoding. With metal tape it was incredibly clean - but the only deck that I could ever play my encoded tapes on was that one deck. Never met anyone else who had the ability to play them, and they were unbearable without the function activated.
@michaeldeloatch7461: You had me at your assistant's first utterance, and you won my heart with your hysterical expressions admiring her from your little bubble as she spoke! New subscribe here!
You missed discussing type C.
It's easy for me now - I have recorded one cassette in the past twenty years after getting my hands on a nice pioneer deck from the 80s, and I can't hear > 5KHz worth a beep anyway so hiss away tape, I recorded without it.
Forty years ago I did use it on prerecorded tapes with the logo and turned it off for those recorded without. For my own recordings, I found it better left off because as a kid I bought TDK or Maxell midprice tapes typically or whatever was on sale when I was running low on blanks, so I got inconsistent quality recordings and therefore dolby was imprecise on playback and annoying.
@michaeldeloatch7461 replies to @michaeldeloatch7461: Oh yeah - another reason I forgot -- neither my early Walkman nor the cassette deck from radio shack I stuck in my parents' car had dolby available so it seemed logical to forgo it when recording back in the house on my deck.
@gblargg replies to @michaeldeloatch7461: There was also HX-Pro, which I believe was a bias modulation scheme that recognized that high-frequency content acted as a bias signal.
@AudioMasterclass replies to @michaeldeloatch7461: Yes I did miss out Type C as I felt that would be overcomplicating this video, Type S too. HX Pro is a different thing entirely and I may comment in future. DM
@nicholassheffo5723: The B-type of even C- type and S-type might not work as well later with tapes played a good few times, though some people just used a Chrome/Metal switch as substitute noise reduction and are happy with it, whether that is a good idea or not.
@sbbinahee: In my cassette listening days i definitely left dolby nr off for the exact reason you say. Instead I would reduce the tone and Bob's yer uncle or in your case, Paul mc cartney 😂
@jessegiles5508: Interesting to hear a take on Dolby B I haven’t come across yet. Every audio engineer I’ve heard speak of it raves about it but as they describe it’s effect it’s hard not to wonder why no phasing effects are mentioned (I guess the curve is gentle so it’s ignored) and the lack of gain for portable decks.
The fact there was normally a switch means it’s no big deal in the real world. Sometimes it sounded better on, sometimes off. All depending on the system and context I was listening in.
I have had the pleasure of engineering and mixing a few recordings on 24 track 2” tape and applying Dolby B and S was a luxury you would be silly not to take advantage of. The quality of that sound isn’t something I’ll forget.
And home on the Nakamichi deck, all Dolby, all day. The Yammie amp took care of the make up gain and the dreaded hiss was gone.
On the school bus though it was worth flicking it off.
I still think the stereo image is a bit ‘altered’ to my ears and I can totally see how some people might seek out releases without it.
I used to love my tapes but hiss was enemy #1 behind a lot of problems. I’m loving the vinyl revival but feel no urge to drag out any old tapes, as cool as they may have been
@polysormi3825: Why is that AI so angry? 😄
@esvegateban: Or we could just use, idk, CD.
@apmcd47: Funny, really. I was told that "Dolby Noise Reduction" as found on cassette decks was for reducing tape hiss that I never really noticed unless I had the music so loud that the neighbours half a mile away were complaining about how loud I had it on! Seriously, though, I never could afford equipment with Type B and have never missed it. I had a sneaking suspicion that it was a con of some sort and would never have used it even if it was on a deck that I owned.
@terryscanlan6738: Who cares? I can't remember when I retired the last cassette deck. Isn't it 2000 something? Digital did not come soon enough.
@desembrey: Audio cassettes existed for one purpose only - convenience. They were a way to take the music of your choice with you, and you accepted the 'worse than AM radio' sound as a price you had to pay.
@benjaminedwards9751: My home deck is a harman-kardon hk400xm that does all 4 tape types with manual calibration facilities. Needless to say, it has Dolby Type B as well as HX Pro. I play these cassettes in my car because I drive a 1997. It sports a cassette player with Dolby and has been regularly cleaned and maintained by myself for 26 years. Friends and co-workers of mine get in my car, and they don't believe me when I tell them they're listening to a cassette. I have to eject the tape and prove it to them, and they are simply blown away by the sound quality. None of them knew cassettes could sound so good. This just goes to show that cassettes can sound absolutely amazing if you have proper equipment that has been maintained and that you know how to use correctly. Yes, Dolby absolutely does work. I've been proving it for decades.
@CamelDudeMan replies to @benjaminedwards9751: how dare you clean and care for your expensive gear >:( Its so unfair that my ashtray noise reduction doesn't work.
@juliocesarpereira4325: At first, I didn't know how to use Dolby B or C. But after I learned that you have to record with this feature to apply it on playback, it did work. And in fact improved the quality of high frequencies whenever I listened on some pocket stereo players. My last tape deck recorder had three heads and it meant I could monitor the recording in real time. And once, I bought a Sony Metal cassette tape. The first thing I noticed was that it allowed a much lounder recording. And as I listened to it in real time, I noticed the improvement such as much lower tape hiss. So in short, metal tapes allowed higher dynamic range and Doby C turned noise floor even lower, so tape his was dramatically attenuated. I was impressed when I found out that although the volume button of my pocket stereo was in "zero", the music was leaking to my headphones. The problem was that these tapes were very expensive and they shortened the lifespan of tape decks heads. So I returned to Chrome and Super Avilyn cassettes using Dolby B or not.
@j7ndominica051: On my Aiwa Creator's Stereo, the level reads back at about 3 dB less. The sound seems slightly muffled and "digitally processed," similar to fft noise reduction that people often overuse. Since there are no test tones on cassette tapes, I wouldn't know how to align it. If a type I the tape is overdriven, it loses high frequencies, so Dolby would see a radicaly different level. I find the best recording level to be where the VU is barely kissing 0. Holes in the tape also get emphasized by Dolby.
The one-sided Dolby-HX works better and allows to maintain high frequencies at higher levels by reducing the bias.
@tori8380: Dolby B definitely helped. But you needed to tweak record and repro levels and bias for best results.
@AudioMasterclass replies to @tori8380: Exactly so. DM
@gratmatassa5432: i used dolby c mainly on normal tape & no dolby on chrome & metal worked well, hx pro helped as well