DOLBY NOISE REDUCTION - Was it GOOD or BAD? Live Audio Comparison of Dolby B and C on Tape
HTML-код
- Опубликовано: 18 апр 2023
- Whether you like Dolby NR or not, it's a thing. I've always tended to not use it, but I still think it's an ingenious solution to a nagging problem on cassettes... tape hiss. In this video, we'll learn how Dolby B and C work, as well as do live comparisons with and without Dolby on Type I, Type II, and Type IV cassettes. Let me know your thoughts in the comments below.
*NOTE - After posting this video, I noticed a lot of background hiss on the recordings, even the digital file. Turns out, recording from the headphone output on the deck was introducing noise. I've upgraded my setup to allow direct capture from my tape decks, so future videos will sound MUCH better. There's a full update on my Patreon page for those interested*
Support us on Patreon: / vintageelectronicschannel
#electronicscreators #vintageelectronics #electronics #cassette 
Наука
Before doing such a "test": You have to calibrate the recording level, bias and if possible the EQ ( this have noting to do with the 120/70 us ) for every tape used, certainly using DOLBY C ! DOLBY C needs the record level correct within 0.3dB and a descent flat frequency response to operate properly. By the way, your TASCAM 112 has audible flutter.
I'm a vinyl guy, but I enjoy a good type II or type IV metal from time to time! I agree with you 100 percent, NO NOISE REDUCTION PLEASE! 😊
In my quest to rebuild my vinyl collection AND feature new releases on the format, I've just ordered a vinyl release of my friend', Patrick Cornelius @pcorneliusmusic album, Acadia: way of the Cairns. Can't wait to get it. It's a perfect genre for analog media.
I think all excerpts in this video sound equally hissy. As you point out in the video description, that is definitely due to using the HP out of the deck. I have found this to be the case as well when capturing cassette tapes to a portable digital recorder. Always use the line outs of the deck, bypassing the deck's crappy in-built HP amp. As for using Dolby: I find it too much hit-&-miss to be of practical use. You need a deck with level calibration to make optimal use of it and it does not transplant well to other cassette decks. I record without Dolby and then route the tape signal through an external single-ended denoiser. 30 dB noise reduction is feasible and a digital capture of the tape signal is hard to distinguish from a CD original in an AB test.
I ended up changing my video recording setup. After hearing the results from this video, I routed an output from my program selectors to my MOTU interface so I can capture the recordings at high quality and record as a WAV file to be used in the videos. There are a couple videos coming up over the next month that use the new system and it sounds much better.
It seems like there are some issues with your equipment. There's an awful lot of noise and distortion in the sound during the demonstration. Even during the 'recording' part where you played the 'original' there was already a ton of noise in the sound. That should obviously not be the case. The playback that followed after that sounded extremely muffled and distorted. This is NOT what tapes should sound like, played on a well maintained and calibrated cassettedeck. Other channels like 'Cassette comeback' show what tapes can actually sound like. Even without Dolby they can sound a lot better than what is demonstrated in this video. This video might give people a completely false image of what cassettes sounded like.
I was never a fan of noise reduction either... Thanks for making and sharing your videos.
Thanks for watching! Next week's video is about Type IV (metal) cassettes and the demos in that video are done without noise reduction and I think it sounds fantastic.
Thank you for posting.
Wow! The dolby was confusing the original treble with noise. I agree with you, in your demonstration, using no dolby at all sounded better. I wanna hear a dbx demo.
I have a couple DBX encoder/decoders. That's on my list to do a demo on.
For me, it depends on how I plan to use my cassette. Dolby is heavily dependent on azimuth. Playback on another machines with Dolby which aren't in perfect head alignment with the recording deck, will usually not give favorable results with Dolby switched on. They can often sound dull and lifeless. If I am making a cassette that will be played back on other machines, I will usually opt for no NR unless the recording contains quiet spots and I am on a Type I tape, then I'll encode with B. If I am making a cassette that I plan to only play on the deck that is performing the recording, I will opt for C. My deck doesn't have S but I am interested to hear how that compares to C. Metal cassettes have lower floor hiss by nature, so you can certainly get by with recording with no NR on those if you have money to burn. When a metal cassette is played back on my recording machine with C Dolby used, there is absolutely no hiss at all. Only the amplifiers transistor hiss is present. Sometimes, as you mentioned, I will record on type I with B NR on, even if the cassette will be played on another machines without Dolby, because the only draw back is usually exaggerated highs which can be corrected easily through tone or treble adjustment. So, my opinion on this is - If you are planning to play your recording on other machines, it's probably best to leave Dolby off. On type I tapes you plan to play on other machines where your recording has quiet moments, I sometimes decide to record with Dolby B on. On those types of recordings you might get lucky on another machine with Dolby on. If you are only playing back on the deck doing the recording, shoot for the moon. It will sound fantastic!
Two crucial points for me are these-- if you use an equalizer, you can boost the treble compass of the cassette when Dolby is IN. That really helps bring up the highs which have been attenuated by the NR system. Secondly, all normal bias tapes are JUNK, people. They were made for VOICE DICTATION. That is it. They were never meant to be a hi fi system. You have to at least step up to type 2 or better tapes to get the treble compass needed.
Dolby noise reduction works only in the most optimum circumstances. Clean tape path, right head height, azimuth, tape speed, tape calibration and level. If you don't, tape will most likely sound muffled. People don't want to go the extra mile to get their decks properly calibrated, so they just rather be stubborn and say that dolby nr never worked and just never use it. But when it works, IT WORKS. Dolby S plus a metal tape is as good if not even better than a CD.
Yes, agreed. I run a 3-head deck with Dolby B, C and S. It also allows me to calibrate the bias to the tape. Dolby S effectively has the same noise as a CD, i.e. none. Dolby C is subjectively nearly as good and Dolby B has a little audible hiss, but way less than recording without. Other than slightly audible hiss with Dolby B, any of the Dolby systems give an overall recording quality with Type 2 and 4 tapes that is effectively indistinguishable from the source, be it CD, Vinyl or whatever. I could certainly never listen to a non-Dolby recording on headphones - the hiss would drive me crazy. However, my first experience with Dolby was in 1974 with Dolby B on an Akai deck and it sounded awful, partly because I only had type 1 tapes, but also because the Dolby was probably badly calibrated and drastically knocked the treble off as well, making recordings sound as though they'd been made from behind a thick curtain. It's a fact that all things analogue are far more dependent than digital on being of good quality and being set up properly if they are to perform well, but that in itself brings its own reward.
My experience has been that I never use Dolby with chrome and metal cassettes, as these usually have a very low noise floor and the record level can be set so high, that the sound acoustically masks the background noise. With normal position tapes, I use the best noise reduction system available, but either when I'm sure that all my cassette decks have the same Dolby calibration and I don't notice any pumping, or when I'm sure that I'll only be replaying on the same deck.
I'm impressed by the wow and flutter stability of your deck, but it seems like hiss a little higher than what I'm used to.
I'm not using NR when recording. I would like to see comparison with S though.
I never get this bad of a result from my less expensive deck. How are the heads on that Tascam? Your results were horrible compared to what I get with my deck, which is probably half the price. None of my tapes EVER sounded that bad, with Dolby on or off.
I don't like to record with NR. But I will buy albums that are recorded using Dolby SR or HX Pro and compare them with their regular Dolby B releases. Nowadays, NR doesn't seem necessary in my opinion. Since I tend to use 90 minute tapes, I'll make two 45 minute "master" recordings onto minidiscs and dub from those. All tracks are normalized to the same volume and I try to record from FLAC or Apple Music's 24-bit offerings. My new cassette recordings sound a million times better than my cassettes from the 1990s. Like you, I also record using Tascam decks (cassette and minidisc). The minidiscs come in real handy when you have friends who feel nostalgic and want one of your mix tapes. I like making mix tapes for my friends for christmas.
My tapes now sound better than my tapes from the 80s and 90s as well. A big part of that is equipment. As a kid, I had a budget tape deck and bought cheap tapes. At 13, I got a brand new Sherwood cassette deck. That was a budget brand, but it sounded way better and had Dolby B and C and recorded on metal tapes. That's when I started really getting into recording tapes and trying to get the best possible quality. Nowadays, I tend to record my "masters" on 2-track 15ips reel to reel. I also make mix tapes for folks. I'm glad I'm not the only one! I've never had a minidisc player or recorder, but it's on my list to get.
I remember Dolby noise reduction. I used to record from sources like vinyl records, and I would get good results using Dolby B noise reduction using Chrome tapes. However, using Dolby C, which raised the signal to noise ratio, tends to sound pretty crappy on equipment which didn’t have it. Most of the more expensive portable tape players did have Dolby B noise reduction, but not C. However, it did matter as to which type of tapes were more suitable. Using Type II or Type IV have better frequency response compared to Type I tapes. Most of the portable cassette players only supported Type I tapes, so you would need a higher end player to play back Type II and IV tapes.
I agree. I tend to use higher end types without noise reduction and get pretty good results. The times I did use NR back in the day, I used Dolby C. It did mess with the high end quite a bit though when I played the tapes back on my Walkman. I didn't mind too much, as I tend to like a brighter sound anyway.
.. Great demo for what it's worth the technical aspect of other comments would go way over peoples heads so you done the right thing with this test. It's exactly what anyone wold do with tinkering and getting there set up right i am on the fence with dolby as i use multi track recorders but i have to ask is the dolby that's built into these systems a gimmick. Why did they bring out stand alone dolby there is so many options in daws that is the reason i would avoid using dolby
I don't think Dolby is a gimmick. I believe it had practical purpose in reducing tape hiss at the low speeds cassettes run at, especially in the early decks. That said, I'd rather deal with the hiss than have my recordings dulled on playback with Dolby B
@@VintageElectronicsChannel .. I respect your knowledge and sharing your experiences with this technology but i do have a question. I own multi track cassette and reel to reel recorders and would love to know. Is the built in dolby b of these systems of the same quality of a stand alone. I am looking at some standalone like a TEAC AN-80 would is give me the same results as something that has dolby b built in with just the regular on off.
@theprogrammerrolandmc3039, I don't think I'd recommend using Dolby with a reel to Reel. Even at 7.5ips, the noise is so low I don't think it would be necessary. I don't have a lot of experience with standalone Dolby equipment, except some Dolby A stuff for open reel. I would think it would be the same technology and result as a built in system though.
@@VintageElectronicsChannel .. Thanks for your help i agree reel to reel is completely different from cassette i never have hiss on my reel to reel.
The hiss is the tape. I say boo to nr. Even with the pre recorded tapes, i play then with no nr and the treble down a scoche
B and C worked great if you recorded and listened to the tape on the same deck for sure but it might not sound so good on another deck. I used chrome cassettes mainly TDK or Sony were my faves but also Fuji had good ones. If you set the level just right it was way better than nothing because the hiss and lack of dynamic range of a raw cassette was not very listenable. If you had a type 1 tape with no dolby it sounded like gravel. Does the youtube compression affect this? I remember hearing the hiss much more even with better tapes.
How about a video on DBX noise reduction and compare it to dolby C and S if possible. ? Sometimes i use no NR and other times just B or C when recording or playback. It also depends on the quality of your speakers and in particular the Mid ranges if you plan to use dolby B or C, There you notice the most benefits in my opinion. A great set of Modern Speakers sounds best with the older vintage receivers etc just as long as you match them correctly in terms of impedance and Watts output. Also modern over ear headphones sound extremely great with vintage walkmans etc. Try them and see.
I have plans to do a DBX comparison to Dolby. I have the equipment, so all I need to do is record a video. It'll be coming up.
Why is there so much noise/hiss in the first place on the Original File? Makes analysis of the NR types a bit moot.
Immediately following this video, I made an upgrade to my setup. I noticed that as well. I had recorded from the headphones output of the tape deck directly into my camera. For all future videos, audio will be captured direct into my MOTU M2 interface. I added an additional output from my DBX program selector to output from all my tape decks directly into the computer. There are a couple videos coming up on the channel that use the direct capture and it makes a world of difference.
I couldn't hear any tape hiss in any of the recordings through the video. In my systems, I can hear the hiss quite clearly, and Dolby B gets rid of it very well. I think it's good, so long as your equipment is good all the way down the line. The way Dolby is supposed to work is that it accentuates those frequencies in the recordings that are then lowered during playback, so there shouldn't be a dulling effect to the high frequencies. If you're perceiving a dull sound, then there is something weird going on, like maybe the biasing of the cassette isn't quite right during recording or something? Somehow, you are losing high end that wasn't properly added into the recording. That doesn't happen for me at all, Dolby B has all the highs and sounds crisp and clear as a bell. C is generally bad because it's too complex and recording and playback rarely matches up well from machine to machine. Dolby S on the other hand is better than all of the others. S tapes sound great played back with no Dolby and with Dolby B or S engaged.
I've never had a machine capable of Dolby S, so I've never personally experienced that one. I've heard it's really good and someday I'd like to find a machine with it. I've always liked a brighter sound profile personally, so I've actually recorded tapes with B and played them without NR engaged to get the accentuated highs. It's definitely a personal preference.
Couldn't agree more. Love Dolby B encoded recordings but played back without any Dolby decoding at all. Works well even om type1s to enhance the treble response. I'm sure that's not how Dolby is intended to be used but works well for me
@@joeclayton2875 dolby only increases the level of high frequency sounds when they reach a certain threshold. if you playback a dolby recording without it on, it's going to distort the music by emphasizing louder high frequency sounds over lower volume high frequency sounds. just simply using the treble control (or an equalizer) will increase the high frequencies more uniformly
I haven't watched this. I've always thought that Dolby Noise Reduction had Snake Oil written all over it.
Yep never like noise reduction always kept it turned off even since I was a kid and I'm 68 years old I had a cassette recorder player 1966 it was a piece of crap but hey at least the existed it was Norelco it didn't sound very good I still have the original cassette tape that came with it they went very good but I agree heck with noise reduction leave it off thanks for the video have a great day
I've never liked noise reduction. I think it makes the music worse, not better.
Nice cassette tape is good
So. Much. Noise. I can't listen to this. The noise your system makes even without the tape running is ridiculous. As far as the tape, I used Dolby S. Great shit.
After publishing the video, I made changes to the video recording setup. I left a note in the video description about that. All videos recorded after this one use the new system.
Type I - All three were too quiet (if volume didn't change) and lost horrible amounts on B and C.
Type II - B and C weren't much different than the original, but slightly muted.
Type IV - Surprisingly B and C did worse than Type II.
Overall, Type II was the best. Now let's hope the newly made Type IIs are as good as old stock.
I've always preferred Type II cassettes. Metal sound great too, but I never felt the price difference was worth it when compared to a well-recorded type-II.
I heard hiss throughout this recording. Using a live piece makes it hard due to background noise.
It would have worked better if the deck was properly adjusted to tape-type (bias, azimuth, ..)
dolby c very bright playback with no decoding. i prefer dolby b no decoding playback.
I have to agree. I like Dolby encoded tapes played back without it. I prefer a brighter sound.
Great minds think alike. I thought I was unique having this view
You were super over biased on that type 1. Proper bias and a type 1 sounds very good with no loss of treble. In my experience with NR, it can sound very good, but there's still something missing and some music makes it apparent, a quiet trebly instrument buried behind loud mids and lows will sound slightly quieter using NR. But not always. Best to leave it off, no processing, just hear what's actually on the tape. Dolby is a cheat that doesn't quite work perfectly.
Chrome tape, no Dolby NR sounds the best to my ears. All version of Dolby NR are worse sounding than the unfiltered tape versions, IMO.
I agree with you 100%
Depends. Didagree. I had Pioneer deck, wjich has outstanding dolby C.
Type I tape sounded terrible no matter what. I always used type II back in the day, and did not use any NR
I generally did the same thing back then.
Hello there... I appreciated your attempt but even the original file playback sounds quite hissy to me.
I have like many others had my share of renewed experience with Dolby. I am mostly using Technics decks that do both BIAS and EQ at 3 kHz. The result is amazing when there is a good tape in, i.e. barely or not even distinguishable from an unprocessed recording, but only with BIAS neutral tapes (Maxell XLII, TDK SA, Sony UX-S and probably AD, HF-S, XLI). But at this point in time you might incur into degradation, a tape that basically isn't able to cope anymore with the compressed dynamic range, which results in drop-outs and other glitches that were otherwise barely ever present without the usage of Dolby.
To make the most out of Dolby without coloring the sound using a standard calibrated deck with no BIAS tuning you have to pick a tape exactly centered in the IEC type slot.
After publishing the video and listening to it, I noticed the hiss as well. Since recording that video, I've changed the capture method for all my decks to eliminate any outside and unwanted hiss. Details in the video description. Good points in your comment though. Both the deck and tape make a huge difference.
I have a Sony deck with calibration and Dolby S. Using a calibrated type II or IV tape with S sounds amazing.
I agree that the first thing I noted in this video as well was the amount of hiss that was omnipresent, completely ruined the validity of these tests IMO.
Also, dude, you recorded these way too hot! You shouldn't be going over 0dB on a regular basis.
Nagrywam zawsze bez DOLBY,szumy mi nie przeszkadzają...
I agree with you. Noise is part of the sound of tape.
I dont think the track you chose to demonstrate is the best because the cymbals of the drums are sizzling away in the same range as the hiss you would hear on tapes, if the drummers wasnt using the ride all the time you might hear the hiss better.
You need to remake this video. You didn't include dolby S.
I didn't have a Dolby S deck at the time. I do now, so it's on my list.
I don't think it was nearly as good on commercially recorded cassettes as on ones you made yourself on your own machine. First off most commercial tapes were recorded hot and lost highs to begin with. Then cassette head alignment was critical and probably the mass production recorders heads were not exactly aligned like yours which would lose highs. I always worked to keep my peaks out of the red as much as possible and made decent recordings with higher grade tapes.
I agree with you. Commercial tapes never sounded good with NR switched on.