ฝัง
- เผยแพร่เมื่อ 4 ส.ค. 2024
- DBX is a noise reduction system introduced in the 70s. It was a competitor to Dolby NR for home/professional use. Why noise reduction? Because audio tape by default is "hissy". You hear SSSSSSSSSSS among the music, amplified in your tweeters. Digital audio doesn't have this issue, so NR isn't needed today. In this video, we make two recordings: one using Dolby NR on a Linear Stereo VHS deck, and another with DBX NR and compare sound.
Follow databits on Facebook:
/ 1databits
Twitter/X:
/ digitalbt or @digitalbt
Patreon:
/ databits
A HUGE thank you to my current Patreon patrons:
Desiree Oudinot
Kyle Fassbinder
Greg
Dylan Olah
Jackson Nieforth
Dan Barlow Jr.
Mark Reed
SilentS
TKB - วิทยาศาสตร์และเทคโนโลยี
Basically dbx would have reduced the noise better than Dolby B but would not have fixed the limited frequency response and wow and flutter. VHS HiFi was so much better and I got my first HiFi deck, a Mitsubishi HS421UR, on April 3, 1987 and it made excellent audio recordings.
tbh: The 15kHz horizontal noise from most TV sets was killing any audiophile ambitions for younger folks anyways... ;-)
I had a friend who constantly complained about being able to hear the horizontal oscillator frequency on many TVs (about 15734 Hz for color, originally 15750 before the color standard). I could hear it when I was a kid and teenager but could tune it out after getting used to it. The 1000 / 1001 factor in the frame rate was to eliminate beats between the color and audio parts of the TV signal and became part of the 1953 color standard.
@@3Cr15w311Speaks boldly how far from the analog days we left.
I just love your old-school handheld videos. They're the best. 🧡
LINEAR stereo? I didn't even know that was a thing!
I've known it was a thing for many years, just not as common as linear mono or HiFi stereo.
Not for long.
linear stereo was very primitive
Had the black pal version of that jvc VCR,
First time hearing stereo movies at home.
Didn’t know you’re back on yt! 😊
Far better than I expected.
Why did you not plug the dbx unit in properly as a pass-through loop? Were you demonstrating something?
The VHS HiFi Stereo introduced by JVC in 1984 (modulated on 2 carriers in the video signal) was much better and did not need noise reduction.
One problem with linear audio on vhs is that it typically has a lot of wow and flutter. There is no masking that with (the admittedly excellent) dbx. The dbx does sound much better than Dolby. I always considered vhs linear stereo mediocre at best. Dbx makes it tolerable.
indeed, as the linear audio head did provide the tracking impulse too. And most decks were aligned in a way to ensure proper head-to-tape contact for the sync, resulting in a more loose tension/contact on the opposite side of this wide head, often visible in playback. in plus the capstan motor's PLL often became desparate if sync was not read properly (in bad cases you got tracking wobble in the picture. But audio was howling too while the image was pumping in horizontal size.)
All this made the linear audio really prone to wow and flutter. So PCM stereo was a logical solution... but what about DVHS....
In total, thinking about upgrading VHS is like trying to upgrade an old PCs. if you upgrade one component, there is always a next thing which could be done too. and finally you end up with a machine where you swapped everything.
BTT: having dolby (even b, wihtout dbx) in VCRs would have been great.
@@rarbiart Dolby B. Yes. And just like with audio cassettes the Dolby B encoded linear audio would still play acceptably on VHS decks that did not have Dolby B. That would have been great.
Thanks! Love the content. Great video
2.56: there is even a shield above the linear head! that helped probably to reduce noise from the drum. (on some machines you had 60/120Hz from the spinning drum in the audio)
I've had VHS decks back through the 80s... great decks, and I never knew that Dolby NR was available on the linear track. I think we just skipped from our 1977 RCA top loader to a 1980 Panasonic portable unit to a 1987 JVC HiFi deck... neat!
Now, i'm thinking I want to make a stripped down portable VHS deck that only plays back the linear audio track. so ridiculously inconvenient but fun... ;D
I'd argue Hi-Fi Stereo was actually better than CD Quality because its notional frequency ceiling is higher than 44.1kHz and more like the 48kHz of studio recordings at the time - there's not any actual quantization going on, it's just acting like a linear tape deck with a blisteringly fast tape speed.
I also have a linear stereo Video 2000 machine, a VR2340. The sound quality is very loud and clear, but it's clearly slow-speed linear and isn't really much better than optical film soundtracks and is indeed very hissy. More than adequate for going through a TV speaker, but they may as well have just stuck with mono for that. It's not as if there were any pre-recorded V2000 titles by that time, and who ever had any OTA stereo broadcasts to record (although thinking about it they probably did in Germany where more of these machines were sold)?
the different hiSSSSSSSSSSes of VCRs (digital hissing on Hifi-VCRs was even worse sometimes) was a constant pain in the ears the years i spent in the VHS and BETA repair shop during alignment runs. (the shop was authorized for in warranty repairs for e.g. Sony, Panasonic, Sharp, Philips)
midrange boosted dramatically with the dbx - I like it for cassette tapes but this might be overkill unless you wanted that heavy compressed sound which could be a cool effect for an audio project, dbx passed drums can sound so good. - someone hard of hearing woudl also benefit from the dbx unit... not so much compression where it's a wall of noise still retains some dynamics
AFM VHS-HiFi eliminated wow and flutter as well. But it would have fixed VHS-HiFi cutting in and out.
What would happen if you double stack Dolby and dbx?
I wonder that too. And the order would matter too!
I found that if I used dolby C and type 2 dbx on a cassette deck, it killed that breathing artifact.
Could you record dbx on to a "newer" Hi-fi vcr?
I used a 140x type 2 unit on a pc wth a noisey sound card. The sound card noise modulated with the signal like tape hiss does.
Is there a way to wire the DBX decoder so that you only need to press the "dbx out" button instead of changing the cable setup?
Perhaps you just did it for the demonstration, yes it's easy to understand.
Anyway, I was to glad when stereo Hi-Fi VCRs came out, best sound recordings ever before burning a CD was a thing.
i have a dbx 150 type 1 and the in and out buttons just turns the compander on or off, and has nothing to do with switching the inputs and outputs, so if u encode a recording by having the in button pushed, u must also play it back with the in button pushed. the out button bypasses the encode/decode function. if properly connected it remains between the tape deck and console and no wire switching is required, or it could be connected to a dbx 200x switchbox that allows u to use the dbx unit on multiple decks as well as contolling equalizers and other audio processing equipment
You said Giulio instead of Julio hahahaha, Giulio would be in Italian. The J sound is like HU, HULIO. Proper advice from a Spanish man. 🎉
TIL!
My dads freind I think has one of these in super mint condition its still plugged in I should try it sometime seee if it plays.
That music gave me a Mr. Rogers vibe.
you swapped the stereo channel plugs for the RCA input to the DBX decoder
Linear sound tracks on VCR's ofen had poor tracking which would kill dbx decoding. Might work great on umatic and type c 1" open real vtr's. I think they ran a 9.6ips.
one drawback of the Hi-Fi stereo was that it couldn't be dubbed over existing recorded video.
Esatto,la funzione audio dubbing infatti lavora sulla traccia normal
linear VHS sucked compared to HI-FI, no compare on specs. VHS HI-FI was the best bang for buck on audio in the day, just poor searching on a 6 hr tape. 20-20KHz +, 90+ S/N, 90+Dynamic Range...And that was HI-FI analog.
i have found that dbx type 1 is superior to dolby b,c, and even s if all the levels are properly set, the only drawback to dbx is it is very temperamental and if your levels arent set just right you will get breathing and/or volume pumping
hi i just checked there was 6800 deck this had alot of toys on it
I've always liked DBX and Dolby A.
L'audio VHS hifi e' indistinguibile dal CD,posso garantirlo,ho delle mie videocassette audio che lo confermano.strano il fenomeno di alcuni videoregistratori che hanno un problema a registrare l'audio se non c'e il segnale video,i miei registrano l'audio senza problemi senza alcun segnale video,tutti
Now there's a nerdy thing I probably would have tried if I had that gear! Still gotta have AFM for SLP recordings.
i seen another youtuber do a repair video on a Vector Research V-6040D vcr and it had a DBX logo on it only time i've ever seen that on a vcr.
That was probably for the stereo TV tuner which I think used dbx. MTS?
@@scottstrang1583 not sure just know its the only time i ever seen a dbx logo on a vcr. the Dolby logo was pretty common on some 80s machines.
I noticed one had much less treble
NR kills the high end.
For most vhs cassette will used dolby b noise reduction
That Run light would irritate the blinkety blink,, me constantly
duct tape to the rescue ... or nail varnish
@@cheeseparis1 doesn't explain the blinking
I had a " hifi" vcr and the sound was terrible. A lot of the time it was like bubbles .
VCR is a tape recorder lol.
Linear stereo on professional machines wasn't really too dreadful. With higher-quality circuitry, higher-quality heads, and manual level controls, plus Dolby, the sound quality was "reasonably good". The AGC was one of the biggest issues on consumer machines. Forever my most hated "feature" on all audio recording devices! On a JVC Duplicator (BR-7000 or later models) or something like an S-VHS editor, the linear stereo was fairly "good". Certainly far better than any consumer deck. The linear audio on the Sony SVO-5800 is surprisingly crisp (relatively, at least). AFM HiFi stereo, or High Dynamic as Panasonic dubbed it - for reasons best known to them! - (labelled HD audio on early machines) is far better, of course. VHS HiFi audio does actually use a system very similar to DBX, but it's not "advertised" and it's non-switchable - it's just always-on/part of the system.
FWIW, Dolby C was used for the linear audio on other VCRs - Umatic-SP and Betacam-SP, (and MII, if I recall correctly).
Regarding AGC, on material of fairly constant level, the circuitry almost always sets the level far too low, hence far higher noise levels. On material of widely changing level, it was even more crap, but in different ways!!
Thank God for digital 😄
My uncle had a stereo linear vhs deck. I had it at my place for a while back in the day and was really impressed with how good it sounded. If I remember correctly it was just shy of a Type II cassette recording. His deck didn't have DNR, so that might have helped. But then I heard HIFI vhs and I was hooked.
@@jims_junk most pre-recorded tapes had Dolby B, even though hardly anyone had Dolby B decoding on their VCRs - which would've made tapes sound extra clear, but also extra hissy! Once Beta-HiFi and HiFI VHS had been invented, linear audio became somewhat of an afterthought - very little effort went into it. It just had to work. Quality wasn't really a concern 🤷♂️ When VCRs mute the HiFi and switch to linear, on a creased section of tape or whatever, the difference is always "dramatically worse" - it needn't be, but it is. On a pro machine the difference is far less "dramatic".
Manufacturers also put very little effort into accurately adjusting audio head azimuth, so straight from factory, most decks were a bit "off".
Even HiFi audio got dumbed-down on later machines. No more VU meters, no more recording level controls, or other "nice features". Progress! Lol.
hi have played around like this in the past
it's not as good as the hi-fi
to all out there liner betacam iis better
than any thing you have here
and betacam is 4 channel on the betacan 75p
decks
there's only one bad side betacam you need ear plugs the fan's the betacam A500P can ear the power
very good point you made
i had to go away from VHS they are all ways
going bad
with betacam easy to find parts from decks
all over the places
With those cheap RCAs... oh man. :) At least an entry level Audioquest interconnect would have been appreciated.
pcm audio sounds like DAT
DAT is PCM Audio
@@mateuszorlinski7334 Thanks dat wist ik dus niet
Home made tapes > anything prerecorded. So even if they used DBX, they probably would have sounded like ass, just like any HI-Fi track, or any prerecorded cassette. The high speed duplication just didn't do any favors for anyone that had done any listening of high quality vinyl, CDs, or laserdiscs.
@@spazzman90 most VHS tapes were recorded in real time, on very high quality machines, with far better audio performance than consumer machines. 🤷♂️ Not all duplication facilities kept their machines well maintained though!
High speed duplication, like the Sony Sprinter, was a thing, but every plant/facility I worked at was real-time. I think high speed was more common in the US than in Europe.
Useless experiment. Linear stereo itsef had its limits and was never designed being hifi. Frequency response (at the very best, on a good day) 50 Hz - 12 kHz.
heaps of jump wires on a PCB just mean the company was too cheap to use a double sided board, there was NEVER a technical reason not to. Theyre ugly to me
These are wires for sensors, motors, for the heads to the head amps and more. Can't do that wirelessly to this day.
@@kyoudaiken Buddy - do you not know what a multilayer board is? You really trying to teach a Mechtronic Engineering Technician how PCBs are made?
@@mycosys First of all in this era, multi layer PCBs were rare and super expensive. Secondly, all wires you see there in the spaghetti are not even interconnects on the same PCB, they connect motors, sensors, the heads on the head drum and more. You've obviously never saw how electronics were made before you were born.
@@kyoudaiken Oh, kid, this is just getting sad.
what is your point? Consumer equipment for retail was always built for a price point. if SS-THT is the cost efficient way and the results meets the spec: this is no shame.
on the other hand: databits at 2:35 (and @kyoudaiken probably) speak about the 1980ies rats nest of wiring loom. i fully understand why the construction was like that. Manual labor was quite cheap, for assembly and even for outgoing inspections and rework loops. the pain of running the QA for the assembly line for this machine: can't imagine.
If you call this "ugly": just skip this video and get yourself a sleek newer machine. e.g. like the ones Funai ran 2003-2006 after they integrated the Philips VCR activity.
13:00 That's the sound of half of music videos in 90s TV. 😬 The sound of incompatibility or letting noobs operate the equipment.
Your narration sounds bad also, you had better audio for a while after having the low bitrate sound for a long time. But no one actually cares about that, so I guess you can continue using that phone to record it, not worth the trouble.