Did that Dolby thing ever work?
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- Опубліковано 26 гру 2024
- A lot of people think that the Dolby Noise Reduction button on their cassette deck should be switched off for playback. Why? Because the sound is dull with it switched in. So did it ever work? Why didn't people like it? ❤️ Support My Channel ❤️ www.buymeacoff...
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
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.
You're technical assistant is the stuff of nightmares.
Yes - can't get past her. I give up.
your, possessive. Not you're, as in you are.
One man's nightmare... 🙂
What program or app does that?
@Zimmy_1981 A combination of five, one of which is me. Trouble is, I’m not sure which one.
Watching this video has rekindled my interest in my old cassettes (all with Dolby off). I haven't played them in over 20 years, but I've now dragged out over 200 cassettes, cleaned and demagnetized the heads on my trusty old Sony TC-FX510R and here I am happily reliving the past. So, thank you.
Wow incredibke collection man. If I had 10 tapes i had a lot, back then, having such a huge collection here wud deem one rich 😂
Ever since 1982, my favorite Dolby has been Thomas Dolby. His stuff always sounds ace!
Yeah, I still own 'The Flat Earth' on vinyl and digital. Even today it sounds amazing both musically and sonically.
'Good heavens, Miss Sakamoto - you're beautiful!'
I once thought Thomas Dolby was the creator of the noise reduction system.
He blinded us with science.
Deep heat for the feet
Dolby B does work, however most pre-recorded tapes sounded better with it off and adjust the treble as needed. With it on you needed to crank the treble to make it sound good. When I recorded cassettes on a good deck it was great. Dolby C with type II or IV was great with a good deck.
Pretty much exactly the same as my own experiences. Cassette tapes sucked because of head alignment issues and the low tape speed, but the tape decks themselves were excellent toward the end of the format's mainstream life--even cheaper ones.
I always used the Dolby switched on. You are 100% correct: if you get a dull sound from Dolby, it's the misalignment of the heads. Another reason is that the tape used was over biased when recorded, or just plain bad. I suspect most complaints came from commercially-duplicated tapes, which were mostly bad. They were duplicated at very high speeds on the cheapest tape possible to save costs.
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).
When I was still using cassettes up to the early 2000s I just used maxell xl-ii with no noise reduction. It seemed to be the best at leaving good response on lows mids and highs. Sure there was some noise, but I could hardly hear it except for maybe the blank spots between songs.
I always preferred TDK SA and SA-X. If the deck is in great condition, I can get away without using Dolby on record.
@@truesoundchris Oh yeah, after 1985. But, before then, their cases were as good as Maxell. For me, Sony was the worst.
Any reason to not use metal? I ended up using a number of those in my recording collection in the mid 1990s.
@@gblargg They were always more expensive, not universally sold, and, frankly, the high-bias ferric oxides (Type II) tapes always sounded better on my Japanese-made decks. In the U.S., Japanese brands were the most commonly sold e.g. Kenwood, Pioneer, Sansui, Sony, Awia, Sharp, TEAC, Nakamichi, Kyocera....
@@gblargg metal type 4 tape wears the heads up to 3 times as fast as normal tape. Also type 4 tape is expensive, costing more than double the cost of type 2 tapes. The performance of type 4 is better than type 2, but not enough for me to pay so much for it plus wear my heads out.
I’ve been playing with a nice Dolby type S deck and metal tapes and I’m actually very impressed by how good it sounds. It’s a lot of fun to see how far an inferior technology can be taken with technology
In my EXPERIENCE Dolby S was the only version worth bothering with at all, and when used correctly gives unbeatable recording quality 😉
Yep, that's the best combination with cassette tape for sure, especially if you're also recording on a 3-head deck to properly monitor the recording level to eliminate noticeable distortion and maximize the available dynamic range of the tape itself.
All tapes were slightly different in their abilities too, with the overall best one I ever found and used being the TDK MA-XG, although they were quite expensive when brand new. (But definitely worth it IF you had a very good quality 3-head cassette deck with Dolby S NR, that could actually take FULL advantage of that specific tape!)
If everything was ideal, the above tape on a really good deck with Dolby S, the signal to noise ratio could be as high as about 85 dB, which is pretty darn close to CD! (~100-120 dB for CD with the best CD players)
@@JoeJ-8282 As a 16 bit linear quantizing format, CD's theoretical maximum is 96 dB dynamic range and signal to noise ratio, with another bit or two lower noise floor using frequency-shaped dither. 120 dB would be 20 bit recording and I've never seen anyone ever claim to get that out of a CD.
@@editingsecrets Yeah, those numbers I mentioned were just some claimed specs of various high end CD players that I remember seeing over the years, I had no way of actually testing to see how accurate those numbers were.
For example, the CD player that I have in my stereo system rn claims to have the theoretical maximum Dynamic Range of 96 dB, but it's claimed Signal to Noise Ratio is 105 dB. I'm not sure if it's actually capable of those numbers in all actuality, because I don't have any way to accurately measure or test it, but I do know that it sounds REALLY great, and it was an excellent deal for me, especially since I found it used at one of my local thrift stores for $15! You really can't beat that for a really good quality CD player! It's not "technically" a super high-end brand, but it's definitely decent, and it works very well for me.
@@JoeJ-8282 When the CD format is fully used - not squashed to hell by "the loudness wars" - it can sound really great! Especially for only fifteeen bucks, wow!
I had a separate dolby unit for my reel-to-reel deck. My friend had an enormous record collection and I would borrow from him and make a dolbyB encoded reel-to-reel copy at 7 1/2"/s. They always sounded as good as the LP.
You've stated it exactly correctly. For 28 years I aligned tape machines physically and electrically, using Dolby-A, B, and SR. Unfortunately the public has not yet acquired "our" level of discernment as to appreciate the value in "hearing" something in the way it was intended (wide dynamic range and balanced spectral curve), they would just crank up the bass and treble anyway, especially in the noisy A** car. Really just listening to un-decoded B-type tapes, makes-up for a dirty cassette deck in a pretty nice way.
A lot of it has to do with whether or not one had the experience of hearing unamplified musicians balance their volume playing together live, as with a jazz combo or an orchestra. That experience gives a reference for realistic playback. If the sounds are all pasted together as a fictional studio composite, there's no actual shared experience to compare the playback to.
I used to record my tapes with Dolby B enabled just as a treble boost. Playing them back, I would turn it off. It helped make up for the limitations of cassette tape.
@@devilsoffspring5519 You not used Dolby C? its my favorite dolby NR
@@quebecforce111 Hehehe yeah, I used it. It works even better than Dolby B, but C is more picky about head alignment and that's just not something that goes hand in hand with cassette tape :)
@@devilsoffspring5519 merci
One feature that sadly was adopted only by NAD (who developed it) and Yamaha was Play Trim, which applied adjustable EQ to the signal before it was sent to the Dolby NR decoding circuit to compensate for alignment issues. It was pretty effective.
Yamaha tape decks have play trim, exactly as you describe.
I have an NAD deck and Dolby works extremely well on it.
Loved my Yamaha 3 head deck. Every bit as good as a nakamichi. I sold it for peanuts when I got married.
I only tolerated compact cassettes in my youth when I recorded LPs to them. I never engaged Dolby noise reduction because, like you said, it dulled the sound. I never understood what the big deal was with Dolby NR, no matter what letter they used.
Where only B was available I found it better to enable B on recording with the gain reduced a bit then disable it on playback with the treble dialed down a little. Just a little.
@J S No, your mother is.
In 75 I bought a Teac 3340S and a Dolby unit that was recommended to me for quieter recordings. I used it for a week or two making encoded recordings that then had to be played back through the Dolby box to unencode what was recorded. I don’t know if I wasn’t using it properly or what, but it seemed like the recordings just didn’t sound as good compared to not using it in the first place. I returned the Dolby box to the dealer and am glad that I haven’t had to deal with it. I used that deck to record a lot of my original music into the 90s. In recent years I have archived most of my old tapes into my daw and am quite pleased with the quality of my old recordings.
Back in the day I used to encode with dolby and play back without, for the extra treble zing. I probably wouldn't do that now.
Wouldn't the largest treble boost come from leaving it off during recording and playback?
I remember experiencing the high end boost when the Dolby switch was off but thought that people were just hearing the boosted high end and preferred that as a psychological comparison, kind of like people prefer the sound of something that's a bit louder than what you're comparing it to. Thanks for clearing up the mystery.
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.
Nakamichi DR-2 and DR-3 owner here, nuf said 😊
Also bias matters, I missed that in the video. And of course, sensitivity and azimuth.
My cassettes from the nineties, almost always recorded with Dolby C sound still terrific.
Sometimes I play one of my old cassettes in my DR-2 and I'm amazed at how they still sound magnificent on my main system.
Tape speed and size matters. CC was made to be lo-fi and good decks got horribly expensive because of that
After owning decks with B, C, and one with dBX, I have to say that I found Dolby C to be the most satisfying overall. Never had Dolby S so can't comment on that.
Edit: And in my own experience Nakamichi decks were legendary. Better than TEAC top of the line IMHO. Could never personally afford to shell out for the great ones, however. Wife insisted on feeding the kids. Priorities. Sheesh.
@NicolaDiNisio Hi Nicola, i have the Nakamichi DR-3 to and i have some questions for you . For recording with type 1 cassette do you use Dolby B or C . Sincerely im like you , i love alot my DR-3 .
@@quebecforce111 I see no reason to use Dolby B for my own cassettes. Dolby C is far superior. Get the bias right and make sure to use tapes of the right sensitivity, or choose one and tune your deck for that tape only, you will need the schematics of the DR-3.
I still have tapes recorded by me in the late eighties with Dolby C that sound terrific.
@@NicolaDiNisio some said the DR3 are one of the best 2 heads of all time and one of the big plus are there releability. sorry english are not my first language lol
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.
I'm a member of the Dolby B team. However, I use a Denon 3 heads for recording and I record at the highest level possible on new-old-stock chrome tapes, then I listen on another 2 heads Denon because I don't want to use the 3 heads prematurely. After watching your video, I now understand the meaning of the dolby sign on the Vu meter, it's the Dolby trigger. I didn't know that
i used dolby c mainly on normal tape & no dolby on chrome & metal worked well, hx pro helped as well
The biggest Dolby type-B issue was with store bought music cassettes. No matter how much cleaning, degaussing, and aligning, of the heads was done, the mastering deficits just wouldn’t allow enough clear signal for the noise reduction to perform its task properly.
Most pre-recorded cassettes were horribly mastered. Plus, most pop music at the peak of the cassette era had loads of treble.
That was because the commercial cassettes were high-speed copied (up to 64X normal speed), so very often they lacked treble response.
@@florianm3170 Yes, they were pretty terrible. I do have some of the “Digalog” tapes, and they have incredibly good treble response.
In my experience, it works pretty well so long as it's for your own recording played on the deck that recorded it, and some decks are very well aligned with one another. Pre-records are definitely a hit and miss, some have given the correct treble response when compared to a streaming version in a/b tests. But no matter how good you can get it to work, some sounds (mostly high textured electronic sounds) can lack detail unless you under bias, but that will also give a treble boost to everything else. Leaving dolby off during recording will keep those problem sounds more intact. 99% of vocal and instrumental music dolby will stay faithful to the source so long as you have a proper bias adjustment making pink noise match the source indiscernibly at 0db (yes even a two head deck with the internal pots adjusted), you won't be able to tell the difference in an a/b test, even with good headphones, volume cranked high. It's just those electronic sounds that go above and beyond the capabilities sometimes. If someone doesn't believe me, generate a sawtooth in audacity, record it onto cassette at 0db, then play it back comparing it to the source sawtooth (match the volumes if required). It will be missing texture, far worse so if you used dolby.
My guess is that electronic alignment alone is not enough. It is also about the quality of tape transport. A perfectly biased deck can measure well on a bench, the Dolby may operate flawlessly, but then high W+F, especially audio-frequency flutter, makes it all mushy and dirty. And then the listener plays with controls to mask this midrange trash with excessive treble. We certainly did it back in the 80s. Fast forward 40 years, and I still do it with my "disposable" low-end decks - while a Revox or a Sony ES sound fine as they are.
@@jmi5969 Most definitely YES about that!
Good quality vintage tape decks from reputable and well known brands, especially the ones that were made in Japan, were WAY better sounding, (because of the reasons you mentioned, among other things), than the brand new cassette decks that are available nowadays, of which all use the same identical, REALLY cheesy quality, mechanisms made in China to modern day, super cheap, "throw away" quality standards!
There's literally NO comparison between good vintage decks and those horrible new ones! There's even videos here on UA-cam on various audiophile and "audio nerd" channels that have done side by side comparisons of both to prove how terrible the brand new cassette decks are in comparison to a good quality vintage deck that has been properly taken care of and serviced over the years. It's actually pretty sad and ridiculously funny how much worse the new ones are vs. most vintage decks!
@@truesoundchris Sure they are. Unless I'm just not a human.
@@truesoundchrisEver try Jean-Michel Jarre - "Oxygene", or Synergy - "Cords", for instance? I beg to differ with your statement, friend. These are decades old, fully electronic but still sound beautiful and remarkably timeless (and very clean to boot).
I remember an interview with Ray Dolby where he was relating the problem of explaining what he did to the average party-goer:
RD: You know that button on your cassette deck?
PG: Yes! What does it do anyway?
RD: It reduces noise.
PG: What noise?
I used dbx with metal tape.
Exactly. What noise?
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. :)
Absolutely correct, particularly as Dolby NR calibration was so level sensitive. As was Dolby A and SR on pro machines.
As a teenager I really wanted a Nakamichi Dragon or CR‐7E, or even that AIWA one that let you adjust head azimuth.
Also the HX Pro & AMTS features really help along w/ metal tape. . I have found that to get the right record levels, it helps-- after recording a track-- to let it play back once all the way through before checking the level. The sound will embed itself onto the tape at a lower level than if one checks it directly after recording. Thanks for you channel..
At the time I went for DBX😄 A while ago I restored my ‘good years’ Technics RSM-255X cassette deck and listened to those old DBX tapes. I was surprised about the high quality of those 40 year old tapes in the 40 year old deck!
Yep, but the problem, of course, was that when you lent a cassette to a friend, surely their deck had Dolby nr, that was incompatible with Dbx, so they weren't unplayable.
At the time I had brainwashed my friends to buy a DBX deck.😄 So no problem there!
@@Erwinhooi DBX for the WIN!
My ex-girlfriend liked when I recorded her tapes with Dolby-B so she could play them back without the Dolby... she's way cooler than me. She loved the blistering high-end.
Most professional recording engineers I knew recommended against installing the Dolby-A system. It was just more equipment that had to be calibrated and reduced the number of machines you could playback with. More stuff to go wrong. Better to have a properly aligned Studer A827 without noise reduction.
I had a Technics cassette deck that had Dolby-B, Dolby-C and dbx. Dolby B actually worked fairly well, but it was a nice and well maintained machine. Dolby-C was muddy. dbx (compander) was abysmal.
Interesting. I grew up with a Technics deck in the house that did a reasonable job with B and C, but the dbx was amazing. Problem was, we usually recorded on this nice deck and played back in all sorts of equipment, so only B ever got used.
Many people don't even understand that Dolby ANYTHING is a 2 way process. You cannot just throw it in if the tape was not encoded in the first place.
This lack of understanding was not just for the domestic market. In the early days of analog Prologic for cinemas, prints would arrive at the cinema often Dolby A encoded. Even if the cinema was a mono none Dolby sound system. Playback sounded quite odd. Very compressed and over bright.
In later days trailers would arrive as Mono, stereo with or without Dolby A. Mostly with no identification on them. Not that it mattered anyway. With multiplexes and mostly nontechnical staff. The Dolby was activated ALL the time, even in mono. Simply because few understood the implications. (or did not care!)
I've even had a Brenda Lee CD where Dolby A reduction had been applied to a none encoded track in the first place. Sounded dreadful, taking it back to the shop was a pointless exercise, they had no idea what I was talking about and could hear nothing wrong.
Ahh, those were the days!
I was taught to get the bias for your tape right, and set the (pre)rec level correct as well. My last deck had bias and (pre)rec level adjustments, next to the normal recording level, and with 3 heads, tuning was easy. Then Dolby worked fine.
I still own a Yamaha KX-200 with Dolby B and C. I used C for recording but never for playback. As they say in Spinal Tap; "You shouldn't do rock albums in Dobly". The KX220 is no longer in my system though. It's languishing on a shelf in the box room. Best sound I ever heard from cassette was from a Fostex 4 track owned by my mate which ran tapes at 2x normal speed for home recording. A 90 minute tape lasted just 22 minutes !
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
My first cassette deck had Dolby C, and I thought it worked quite well, but I always used the best quality blank tapes I could afford and I never bought pre recorded cassettes. I did sometimes resort to switching the Dolby off when playing the few pre recorded cassettes I ended up with to compensate for their poor quality.
When I was really hard up, I'd use the pre-recorded cassettes for session tapes. : )
I knew the Dolby B button worked and it did reduce tape hiss but I always found it dulled the high frequency of the music too.
Great explanation. I really like your clear technical approach.
This may be an explanation, why I sensed that Dolby only was working „from time to time“ and decided to switch it on or off by ear depending on the tape played back.
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!
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.
I still have a Revox A77 and an external Dolby box made by Advent 100A. It works great. If you play a tape that was Dolby encoded with Dolby switched out, it plays with excessive treble. Some people equate this with "better".
Back in the days when it was common to send a client home with a rough mix on cassette we used to use Tascam 122 cassette machines biased for TDK chrome tape. These copies never had Dolby B applied and sounded terrific. My production reel to reels also did not use Dolby, we inserted dbx noise reduction and it was (and still is) fantastic.
You can believe what you want. I could care less about this noise reduction as it took the life out of recording. I used to use it, but it took out more than it opened up. Most could care less about recording analog regardless which tape format they use. I choose not to use it anymore. More circuits used equals more chance of noise introduced into the signal path. You choose what suits your situation and needs. Your ears are the only ones that matter in this hobby.
My Aiwa AD-F770 calibrates automatically for each tape you record onto, very useful. I used Dolby B for tapes to be played in the car (yes, Dolby on the car stereo too, only recently removed it) and Dolby C for home recordings.
The key to a proper working Dolby system is that at playback the audio must have exact the same level on all frequencies as on recording. Therefor a good aligned tape must be used. In the 80's I bought the "really good" real chrome dioxyd (CrO2) like BASF or Agfa. But today, some decades later, (omg, I'm old) these tapes lost between 6 to 10 dB playback level, so they can't be played with Dolby on anymore 🙄
Basf chromium cassettes had the best "Type II" tapes, but they sounded well only on european brands deck, or with the Nakamichi 'cause they needed an higher amplitude bias signal (not only in percentage). Then the japanese brands like Sony or Tdk made chromium-equivalent tapes with cobalt, to work good also on the majority of japanese decks.
Got Denon and Teac cassette decks. Japanese decks play better with Japanese tapes like TDK, Sony, Fuji, while BASF Agfa or Philips play better on european brands like Gründig
@@CaptainDangeax Exact 🙂
One of my decks has autocalibration and I have a small collection of 25 different Type I and II cassette tapes from brands including Maxell, TDK, BASF, Sony and Philips. I'd say the deck can calibrate itself properly (ie. with a maximum difference of 1-2 dB between input and playback level) to 50-60% of those cassettes. In these cases, recordings with Dolby B or C sound excellent. That is, as long as I play them back on the original deck. Overall, I find Dolby to be fiddly and very sensitive to alignment differences between various decks, as you pointed out. I do not bother with Dolby anymore ever since I put an external single-ended denoiser in my playback chain.
Once upon a time, I had to send my Fostex X15 away for repairs. Meantime, I was given an X26 to use. Everything was fine for recording. But soon as I put in a tape made on the X15, everything went to ***t. Lost the highs, the lows, was left with an ugly sound, worse than AM radio. Just saying. : )
I am one those people who tends to switch Dolby off on cassette decks. However, some years ago I made a lot of music on an 8 channel Fostex 1/4'' tape recorder with Dolby C and it worked fine - as long as I used the good Maxell tapes (the machine was probably adjusted for those) and planned which instruments I put on the individual tracks. Since there were only 8 tracks I sometimes had to have more than one instrument on some of the tracks. If I put an instrument rich in treble - like strings - on the same track as the drums, I could hear the strings loose treble when the snare drum was hit and than gain treble again until the next drum beat. But apart from that quirk it worked fine.
@audiomasterclass
I believe type A cost $1000 CAD per track.
I always use Dolby C during Mastering my own mixes from DAW to Cassettes . After the master is made ------------------again use Dolby C during play back and record back to DAW for CD production . My decks are Yamaha KX 800------------TEAC V-870-----------Yamaha KX 580 (2 Head) and Sony 611S . Indeed proper tape tuning is must as all my decks come with tape tuning option. For play backs I use 2 head decks Nakamichi BX 125 ---------------Yamaha KX 300 and Nakamichi BX 2 .
If the music you listen to is already noise, dolby doesn't fix this. Seriously, I think of Dolby NR as something like the RIAA curve that goes way back with records. Even reel-to-reel decks without dolby have a curve I've discovered. I thought it would be brilliant to run my reels at double speed and digitally record them at 96 KHz sampling rate and simply change them to 48 KHz in software to save time. But I did a test first with white noise and frequency sweeps to discover that there was a frequency response difference and I assume a type of curve. So I've done all of my digitizing of reels at realtime speed.
The reel to reel EQ curves are different for the various speeds. They're more agressive at the lower speeds. There were two slighly different standards around the world for many years although they didn't differ by a large amount. These were the CCIR and NAB curves. The cassette system also has pernament EQ curves which are always applied regardless of if the Dolby treatment is further applied or not.
Dolby should have made playback level adjustments available on all decks with Dolby NR to reduce the compatibility problems. I still have some more than 30 year old Dolby B/C recordings on TDK and Maxell tapes that sound almost perfect. But most pre-recorded Dolby B tapes did already sound a little dull when they were brand-new.
I'd say yes to this, but for non-technical people, probably 99% of cassette users, it would probably be one more thing to get wrong. DM
@@AudioMasterclass I wonder if cassettes could have had a brief either ultra-low or ultra-high tone for the deck to measure and align to automatically? (I suppose I'm adding cost to the decks now.)
@@GeneSavage That could have been done. There were tape machines that used a pilot tone to improve stability but they never caught on. I can't remember the details but perhaps Google knows something. DM
@AudioMasterclass you could hear those calibration tones at the beginning of some pre-recorded tapes that were created during duplication to calibrate or QC the resulting recording. Some high-end home decks do have calibration tones to automatically set bias and recording levels. Nakamichi decks could also auto adjust head azimuth.
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.
Dolby S. All I know is that if I flicked the switch (sensibly and unconveniently hidden on the back of my old Fostex G16S) to off. Niagra falls arrived. Over 16 tracks on half inch tape Dolby S was fantastic.
I found the Dolby Type C on my E16 perfectly adequate. DM
I always used Dolby C NR. I also fine tuned the bias of the tape by recording noise of my FM tuner (finding an empty spot where there is no station). If the noise was identical between recording and playback it was ok for me. This gave me good results with my Kenwood cassette deck.
I once bought a pre recorded cassette, recorded with dolby-B or normal Dolby as I called it, and it indeed sounded dull. That was the first and the last pre recorded cassette that I ever bought.
Of course it is all past tense. I am in the digital age now and relieved of all these goodies I used to love in the past.
Yes I remember the FM noise trick. With my deck opened up and a schematic to hand it was possible to set both level and bias.
I leave Dolby on and I always try to match it to the correct Dolby. B recordings to B and C to C, etc. Although these days I tend to make my recordings in C. The recommended tape for my deck is TDK D, but I use a wide variety of tapes that work fine. TDK D, Memorex DBS, Maxell XL II, UR, BASF you name it. But my favorites are the D, the DBS and the XL II.
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.
I was never a big fan of Dolby NR. If I used it for a particular recording, it was B-Type, never C-type. I think it also has to do with the fact I didn't know at the time how it worked. Only recently I learned more about it, since I started experimenting with the software tools described in my comment on your previous video. Now I only use dbx on my cassette deck with dbx or via software DxII on the other deck. I love dbx.
Good video. Agree with everything, and I think I understand. However, I only record cassettes for playback in my car and my car cassette player has no Dolby. (Yes, I play cassettes in my car in 2023!) So if the playback machine has no Dolby, am I right in saying there's no point in recording with Dolby?
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.
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.
There was also HX-Pro, which I believe was a bias modulation scheme that recognized that high-frequency content acted as a bias signal.
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
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.
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.
I used my Nakamichi ZX7 with metal tapes, usually TDK, and the Dolby C switch in the 'on' position always, for about 20 years. I don't use the deck or the cassettes anymore, but it worked great through the 80s and 90s. Still have the vinyl records and the CDs I bought in the 90s and 2ks. The vinyl records are the best in the end.
There is exactly one system that I know of where Dolby Type B worked really damn well. It was a Technics system from the 90s. As a small child (in the early 2000s) I borrowed the old NDW-cassettes from my aunt. They were purchased cassettes with the Dolby-Logo printed on them. On this system, the highs were still very clear despite "Dolby" being switched on, but less noisy. It never got muffled. I Think, the azimuth, the tape path, the Dolby-Level, the playback-level and every other factor were probably right on this system. I have only had negative experiences with other devices so far...
I recorded a bunch of vinyl records using Dolby-B and some using Dolby-S. I’d occasionally A-B a vinyl against the tape I had just recorded and to my critical ears they were quite good.
(From David) I always have Dolby switched in(on) & utilize Type C when the tape has been so encoded. There are some "noisey" environments, however, in which the sound "improvement" is perceived as limited.
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.
I've found that recording in Dolby, and playing it back on Dolby from another player (my car) actually makes a positive difference. Versus not recording in Dolby, and trying to play it back with the setting on.
Dolby works best only in the cassette deck (assuming the deck is in perfect condition) that recorded the tape with Dolby...
I have many decks, alignment tapes, service skills etc ...
If I had to use NR in a cassette I would choose DBX any time...
But usually I record cassettes without NR... that's me ✌️
You're correct to talk about alignment, and 3 head decks with fine bias help that by ear. My deck generated tones to assist. I used Dolby C too (a video on that?) and I also used dbx, there's a type 1 and type 2 (my cassette was type 2 I believe) but Dolby A sounds similar (in operation) to dbx or have I missed the point?
What an amazing channel and content, i love it so much.
From this video, what I've gleaned is that Dolby's noise reduction schemes are not only frequency dependent, but level dependent as well.
The fact that low level portions of the signal are raised during encode(recording) and lowered back to original ratio during decode(playback), indicates some kind of dynamic processing - compression & expansion? - going on as well.
So the cassette Dolby schemes didn't just raise some frequencies during encode and lower those same frequencies during playback, there was also a sort of "compansion" process at play here.
Correct. It was a compression/expansion process.
Yes, there is the standard EQ on record and playback on all decks. This has a constant frequency curve and is not level dependant. The Dolby B and C systems effectively compress the higher frequencies by applying more gain to them during their lower levels during recording and less gain on playback to return them to the correct level. The standard EQ operates after the Dolby processing during recording and before the Dolby preocessing on playback.
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.
It's been working for me on the tapes I recorded myself. The results are mixed on pre-recorded tapes. I used to record with C for years but eventually moved to B, like the overall result better.
The best results I ever had recording Dolby B tapes was in 1980 using a quite expensive Aiwa AD6900 machine that had a pretty involved manual tape tuning facility which - if used properly each time before making the actual recording - made brilliant recordings that would also play faultlessly on other machines too. A couple of minutes well spent each time before making a recording.
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.
I own some Nagra recorders including a IV-S. (2 in fact) Some time ago I found this Bryston 280B noise reduction unit with 2 Dolby SR cartridges in it. Its very hard to hear any difference in the recordings with or without. But I am almost 67 now. So it must be my hearing! The Nagra has always sounded good to me. Yes at 15 inch.
Dolby works, sometimes. It's like you said, it's a companding system. But unlike DBX it sounds okay with it off. So, if it isn't working quite up to expectations and you have to switch it off because it's a home recording that didn't have it or for what ever reason, at least you get a boost in highs.
Thank You Sooooo much. Finally the missing tutorial on Dolby. Again, thank you!
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.
In the 80s the studio I worked in used had dbx noise reduction rack units for each track on both 2 track and multitrack machines - lots of rack units. We thought that worked very well. At home on my cassette deck, I never used Dolby B - even tapes recorded and played on that machine sounded dull to me. But the deck also had Dolby C, and I actually thought that worked well for my own recordings. I used it all the time. Not sure the difference between B and C. Will have to look it up. Thanks for the memories!!! No wonder we were so happy to get DAT! :) Love your videos!
I'm sure it works but there are so many variables that the average user can't be bothered with mitigating. If a friend offered to record something for me, I'd always say to them, "DO NOT USE DOLBY", because YES... I would always get a dull sounding cassette if they did. In addition, many of the "Walkmans" I had over the years didn't have a Dolby switch so it didn't make sense to record with Dolby. Right or wrong, I almost exclusively used BASF Chromdioxide and even Metal tapes and push the levels as high as I could to combat tape noise. No idea if it made that much difference but I'm sure I told myself it did. I recall having a few decks over the years with Dolby C and do remember experimenting with it. Unfortunately, so few decks had it that again, it didn't make sense to use it when recording in case the destination player didn't have Dolby C.
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.
Dolby did what it said on the tin, it was purely down to ensuring due diligence was done on your machine, also the quality of the cassette deck had a big a play on it too,
My main gripe was the shocking manufacturing quality of pre-recorded tapes, these where always hit and miss especially as they where massed produced at speed.
Frequencies where usually all over the shop, too much low and not enough high
Some of the pre recorded tapes are just awful. But I think it's because some of the record companies recorded on really trashy cassettes. And this seriously hurt the reputation of the cassette.
D B it works well enough for me when used correctly. It also worked really well when a Dolby encoded tape was played back in our old car cassette, non Dolby, player...helped lift the music above the car & road noise.
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.
A Good Alternative in the 70s:
Philips "DNL"
I made the same experience that is described in this video and never used Dolby B on any of my over 600 cassettes since my first Hifi tape deck in the end of the 70s, that was capable of Dolby B. I didn't want to destroy my recordings with this crap, that, when playing back, reduced high frequencies very agressively when using it with playback, too, or made them too shrill, when not using Dolby at playback.
What was very good in my eyes btw. ears, was on my first Hifi tape deck from 1975: "DNL", "dynamic noise limiter" by Philips.
This worked like a charm:
First I did not have to destroy my recordings, as DNL was for playback only. A huge advantage, as my cassettes were recorded neutral and universal.
Second it worked by cutting off some high frequencies at very low volumes, when noise can be heard easily, otherwise it did not filter too much (or nothing?). It is interesting, that in low volume passages I never heard that loss of high frequency, as one could assume. But the noise on the other hand was canceled so much. The handbook of the machine told, that low volume music had automatically fewer high frequencies... I don't know, if this is true (?)
So with DNL there was never the impression of missing high frequencies like with Dolby recordings, while noise in more silent parts was reduced very effectively.
I dont't understand, why Dolby was such a success in opposite to DNL. Maybe, because with cheap chrome cassettes in the end of the seventies the noise was not a real problem anymore for most of us, especially, when the cheap and very, very good tdk sa 90 cassettes came out.
Dolby S did a lot to improve the higher frequencies in consumer-level tape decks. That one really worked.
My first encounter with the Dolby Noise Reduction process came in the form of a stand-alone component made by TEAC, the AN-50. It required 4 pairs of stereo patch cords connected between a single tape recorder and the amplifier. The feature that I found most useful was a built-in 400hz tone that I used to set VU levels. The unit did clean up and improve the sound quality to some extent, but I took a different approach to resolve the source of the noise which was to record on higher quality tape to begin with. I still have the AN-50 and use it as a tone generator. I have had no need for the Dolby process all these years with clean recordings across the board.
It worked properly, whether it’s A,B type, C, S, SR… as long as it’s aligned properly at *each deck it’s played on*. which is not always feasible.
I spent literally years in the 80’s trying to find a home deck that matched a car deck in speed, alignment, and Dolby tracking. It was horrifying.
In the studio everything was aligned before record/playback so that was easy to troubleshoot.
I like it and it does work. I used it on just about everything except tape running at 30 ips 1/2”.-
Exactly in that manner I used Dolby B , but Dolby C was tremenduous on Pioneer deck, forget which it were. It was good piece of hardware. Then, I made Compander. Bro, it was quantum leap not for one men, but for humanity. Even today, my recordings under compander sounds equally to CD quality. And all of that on , say, maxell normal tape. Repeat: I made that compander, by very well known schematics. Not my patent. But, anyway, it was huge success. Thanks for patience
One thing that I'm not sure you specifically mentioned is that Dolby B was always intended to be something that did not spoil the music too much on non-Dolby playback - since very many portable or car players didn't have it. Since our hearing is less responsive to high and low frequencies at lower sound levels (hence 'loudness' buttons on some hifi amplifiers), then the Dolby encoding that has boosted lower level treble frequencies will sound fine anyway, especially in a noisy environment. But not on your hifi at good sound levels in a quiet room.
Thank you for what I think is a very good explanation of why it doesn't always work properly - I can remember frequently having to clean heads when the music didn't sound quite right.
It was the same for Dolby Stereo in the cinema, which I first experienced with Star Wars in 1978 (we got it late in the UK). It was a real wow at the time compared to normal cinema sound. But the point was that the same print could be played in a non-Dolby cinema and it would still sound good. In fact, probably better due to more detail. DM
@@AudioMasterclass That's interesting, thank you.
What we need is plugin that simulates all types of Dolby decoding, A, B, C, S, SR (And dbx I & II etc, come to think of it.) I haven't recorded to cassette for going on twenty-five years. I have had to transfer from a cassette provided by a client, (and come across reel-to-reel tapes of various formats that were encoded as well).
My Denon DRR-730 cassette deck (now 26 years old!) has Dolby B and C. The manual says that Dolby B only has noise reduction up to 10 dB, while Dolby C has up to 20 dB, and uses "an antisaturation network and spectral skewing circuitry". I've not recorded cassettes in several years now, but my recollection is that I mostly used CrO2 tapes and Dolby C. But for the few pre-recorded cassettes I purchased I never knew what Dolby version was supposed to be used, so I would use my ears and choose the best sounding. I don't know if I ever chose "right" or not (as intended by the cassette distributor).
The deck also features a "BIAS FINE" control in recording. Turn the bias control counterclockwise to "decrease the bias current" and boost high frequencies, and clockwise to reduce them- the manual implies this is to allow users to match their personal listening tastes. I never really played with this much. Does this finely adjust how much noise reduction occurs (versus the default for whatever particular Dolby is being used?
The deck also features something called Dolby HX-Pro headroom extension system. There is no switch for this, it is automatically applied to recordings. The manual claims that it lifts up the saturation level in the treble range, that it makes normal and CrO2 tapes sound closer to that of metal tapes, and that it operates independently of Dolby B and C.
I'm curious about this... it seems to me that two systems each independently altering the recording might cause problems?
The HX-Pro, developped by Bang & Olufsen and licensed to Dolby, is not a noise reduction system. Just a wise trick to give more headroom at high frequencies for tape recording.
High audio frequencies act a bit like the AC bias frequency mixed in the record heads during recording. When high frequencies reach a sufficient level, the HX-Pro decreases the amount of AC bias. With this technique, higher level of high frequencies can be put on tape without saturation.
I found not over-biasing and creative use of saturation to be way more important. NR is just a bit of extra icing for dynamic range
I leave it of, mainly because my WM-22 doesn’t have support for it and it does sound fine without Dolby as long as you use IEC type 1 or better tape.
My decks are the Denon DRS- 810 & AIWA AD-F700. MO is that using Dolby C actually enhances the sound. See owners manual for DRS- 810 pg 10
I was so obsessed with Dolby level and azimuth I purchased alignment tapes from Sony mainly because they were affordable and I had the proper equipment. My most foolish purchase was a Teac Dolby level tape and I had to sweet talk a Teac rep. to sell me one for $100.00 bucks. The only saving grace with Dolby is if you play back a tape made on a different deck and it sounds dull if you switch Dolby off it will usually sound much better.
I admit to buying hundreds of blank TDK/SA and Maxell uD something II tapes. I struggled so much trying to get timing down on recording records. But, aside from that, I thought Dolby worked if you pushed VU to +2-3. This seemed to be the case on the multiple decks I owned. If I recorded to 0 VU I get a low dull playback with Dolby. I tried DBX instead but it seemed to produce weird artifacts with dynamics.
It worked because, when recording with a level higher than 0VU, in practice Dolby never intervened on the signal, even if it was on; Dolby's logic, as explained in the video, was to reduce the background noise only when it became perceptible, therefore when the signal dropped below 0VU.
@@carminedambrosio7 I guess I understood that from the video. What I failed to mention is it wasn’t explained. Nobody I ever spoke to understood what you were supposed to do to use Dolby NR.
@@stevezeidman7224 I guess it all comes down to what the ears have to say about the playback.
I used to have a 1/4" tape, open reel recorder, that was a 4 track. With it, I had the 4 channel DBX noise reduction unit (One channel per track.) If I remember right (it's been over a couple of decades), when I would record tracks 1, 2, and 3 (Including drums on one of these three tracks) and then bounce all of them down to track 4, if I were using DBX, the drums would modulate track 4. On track 4 you'd get the instruments from tracks 1 and 2 (assuming the drums were on track 3) being pumped, up and down, volume wise, on track 4. The drums would cause the noise unit to turn up and down the volume on track 4 (loaded with the instruments and the drum), to the beat of the drum. I think that I just turned off the DBX unit completely, because of this problem when bouncing tracks. I' would just record the tracks fairly hot so that the signal to noise ratio was good. If drums were on a single track, by themselves, this wasn't a problem with using the noise reduction unit (the DBX.) But, when bouncing tracks, the drums and the noise unit, together, would wreck the thing. ((PS: On a different note. Having TWO, four track recording machines, like they did on Sgt. Peppers, is a major advange, over having just one, four track machine. I say this because when they were premixing (bouncing all four recorded tracks from a recorder, to one track on the second recorder, they could put scratch tracks on tracks 2,3 and 4 of the second machine, as a reference. With these scratch tracks on the second machine, they then could determine how loud each of the track being mixed down from the first machine to the second machine, should be. If you're only using one four track machine, you don't have scratch tracks to use for reference volume levels. So, premixing, for most people, who had only one four track recorder, was more difficult that what The Beatles had to work with on Sgt. Pepper. There were no scratch tracks to refer to for setting volume levels of the, to be premixed, tracks. You had to imagine the other tracks sound, without actually having heard it. The old sayings about Sgt. Pepper being recorded on a four track is wrong. There were TWO, four track machines that they were using. That is a big difference from having just one.))
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 .
Worth it though. Do you have a link?
@@AudioMasterclass no sorry it was a few years ago
I have a Nakamichi RX-505 that was recently serviced. Both Dolby B and C work great. I feel like Dolby C doesn’t work as well between my deck and WM-D6C, and Dolby B on my WM-D6 sounds great! But I think the head on the WM-D6 is better. So I use Dolby B when recording for my Walkman for playback, and Dolby C when recording for my Nakamichi for playback.