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Useless functions on music equipment

Started by Icehaven, July 10, 2018, 10:00:31 AM

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Sebastian Cobb

That sounds like the hiss was either present in the source or being introduced somewhere before the tape.


buzby

#32
Quote from: JesusAndYourBush on July 12, 2018, 11:21:10 AM
Yeah it's B and C I was referring to.  On more than one occasion in a simple experiment I'd make two recordings of something, one with dolby on, and one with it off.  Then play back the recordings with dolby off.  The one that had been recorded with dolby off sounded pretty much the same as the original (it'd probably have more hiss but the difference would be minimal and not noticeable for just one tape generation), whereas the one with dolby on had a large amount of hiss added to it.  Now play it back with dolby on and it removes the hiss.  So dolby appears to be adding hiss only to take it off again... but the resulting recording is still worse than the one you recorded with dolby off because its taken something out of the recording making it sound less good than the original whereas the one I recorded with dolby off still sounds good.  So, erm... what's the point of it?
Noise reduction systems in general were devised to make up for shortcomings in magnetic tape recording, such as hiss and noise induced by the transport mechanism (this is even more of an issue on cassettes, due to their dynamic range being limited by the low speed of the tape and the narrow tape width).

To try and work around these deficiencies the noise reduction systems used companding - compressing the frequency range of the signal to be recorded away from the frequency bands tape performs worst in (the low and high frequencies), and then expanding the recorded signal back into those frequency ranges on playback (a similar system is used in FM broadcasting - the FM encoder at the studio compresses the signal to a narrow frequency range for transmission to avoid cross-channel interference and the decoder in your radio expands it back out again). If you play back a tape recorded with Dolby with the noise reduction decoder disabled, it will sound worse than one that wasn't recorded with Dolby enabled. All the signal will be compressed into the middle with very little bass and or high frequencies. This means the low-frequency rumble and high frequency hiss that are normally partially masked by the music become very audible

Basically if it was recorded with Dolby NR enabled it had to be played back with the decoder enabled otherwise it would sound shite (this was even more of an issue with Dolby C - B and S weren't as bad for playback on decks that didn't have the required decoder).

Quote
Later I had a tape deck that had something called Dolby HX-Pro.  There was no button to switch it on, I asked the the guy in the hifi shop about that and he said it just sortof does its stuff.  I never noticed it doing anything!  A scam?
HX Pro was licenced to Dolby by Bang & Olufsen (they came up with it for their Beocord 5000 tape deck). It isn't a noise reduction system, but a way of extending the headroom (hence the  name HX) by fiddling with the bias signal level during recording based on the frequencies in the input signal rather than just using a constant bias frequency. It basically means you can record to the tape at a higher signal level before you encounter distortion. It's only applied during recording, and the resulting increase in headroom on the recording is available to any playback deck without needing a decoder (it became common on prerecorded tapes for that reason).

JesusAndYourBush

Quote from: buzby on July 12, 2018, 11:48:54 AM
Basically if it was recorded with Dolby NR enabled it had to be played back with the decoder enabled otherwise it would sound shite (this was even more of an issue with Dolby C - B and S weren't as bad for playback on decks that didn't have the required decoder).

For me, the recording recorded with dolby on and played back with dolby on still sounded inferior to the recording made with no dolby at all.

Thanks for your explanation.  I was aware it was doing something strange with the audio, I just wasn't sure what.

I think Mr Dolby should have gone straight to stereo and not wasted all those years fiddling with noise reduction.

Depressed Beyond Tables

Quote from: icehaven on July 10, 2018, 10:00:31 AM
I have an old-ish Sony MP3 player that has a 'Zappin In' button which when pressed causes the music to fade away with a whooshing noise over which a synthesised American voice says ''Zappin in'', then it proceeds to fade random tracks in and out for 10 seconds or so each, until you press the button again, then the whooshing noise and voice come back, only it says ''Zappin out'' this time, then goes back to playing normally, but not to what you were listening to before.

I've never fathomed why this exists, apart from giving the MP3 player's owner, the person who put the music on it in the first place, a little taster of the selection in case you can't decide what to listen to and/or can't remember what's on there. Even if that is what it's for (which is in itself quite pointless really) the voice is so annoying and the fading in and out so messy and awkward to listen to that it's unlikely to be used much by even the most indecisive person. And to top it all off the button is naturally positioned in such a way that it's extremely easy to press by accident, so instead of turning up something you're getting into you get ''(WHOOOSHHHH) ZAPPIN IN...'' and a fade up of something completely different, and whatever you were just getting enthusiastic about is gone and the moment is lost.
Is this just an anomaly or is it common to find this kind of supposedly useful but actually pisspoor 'feature'?

I remember a 10-second-intro feature on old CD decks. Don't know what the point was. It simply played the first ten seconds of a track and then moved onto the next song with the same thing. Maybe it was for A&R men who needed to save finger energy when skipping through bundles of hopeful bands. Or it was a testing feature to check whether the CD had been burned flawlessly.

?

buzby

Quote from: Depressed Beyond Tables on July 12, 2018, 07:06:59 PM
I remember a 10-second-intro feature on old CD decks. Don't know what the point was. It simply played the first ten seconds of a track and then moved onto the next song with the same thing. Maybe it was for A&R men who needed to save finger energy when skipping through bundles of hopeful bands. Or it was a testing feature to check whether the CD had been burned flawlessly.

?
Intro Scan, it was called - it was intended as a quick way for you to find a track on a CD if you couldn't be arsed looking for the booklet. It was probably more useful on things like CD Walkmans, car stereos and Cd changer jukeboxes where you wouldn't have access to the booklet.

Icehaven

Quote from: buzby on July 12, 2018, 10:32:28 PM
Intro Scan, it was called - it was intended as a quick way for you to find a track on a CD if you couldn't be arsed looking for the booklet

Or pressing the skip button at your own convenience.

Sebastian Cobb

It probably seemed like a brave new robotic world when you compare it to trying to find that track on an lp when you are unsure of the title.

JesusAndYourBush

Quote from: icehaven on July 12, 2018, 10:54:14 PM
Or pressing the skip button at your own convenience.

If you were shitting then Intro Scan would be quite useful.

Sebastian Cobb

I could do with intro scan. My nad cd player struggles to find high-numbered tracks these days. It's either mechanically dying or it's got some muck on the shaft that lets it seek.

Depressed Beyond Tables

Quote from: JesusAndYourBush on July 13, 2018, 01:29:55 AM
If you were shitting then Intro Scan would be quite useful.

What if it lands on the song when you're mid-business?


Icehaven

Quote from: JesusAndYourBush on July 13, 2018, 01:29:55 AM
If you were shitting then Intro Scan would be quite useful.

I'm not sure I'll be buying any more Sony products if they insist on including major design features that are only any use if you go to the toilet a lot and have a terrible memory. I'm not sure that's a customer demographic I particularly want to be included in yet. Maybe in a few decades.

kngen

The 'index' number on CD player displays (usually beside the actually useful track number). The only time I've seen it used to any effect was when, on a secret track, the singer counted in '1 ..2..3..4' and it dutifully counted up alongside him. That was fun.

I presume it was for different movements in classical music, but both Deutsche Grammophon and Naxos seemed to have ignored it completely and just divided things into tracks like a normal person.

Sebastian Cobb

Part of the CD standard included a pre-emphasis flag. Basically it tells the CD player that the top-end was boosted during mastering (by upto 10db) and that the player should turn it down again.

It wasn't used that much and only really during the early days. I don't think I've ever seen one in the wild. I've definitely heard some tinny early cd's but they also sounded tinny on every player including my dad's CD-104 which definitely had the function as I've seen the relays inside it.

a duncandisorderly

Quote from: kngen on July 13, 2018, 05:30:41 PM
The 'index' number on CD player displays (usually beside the actually useful track number). The only time I've seen it used to any effect was when, on a secret track, the singer counted in '1 ..2..3..4' and it dutifully counted up alongside him. That was fun.

I presume it was for different movements in classical music, but both Deutsche Grammophon and Naxos seemed to have ignored it completely and just divided things into tracks like a normal person.

sound effects CDs, talking books.... I saw some CDs in the early 90s that had two side-by-side mono tracks of books being read. you needed the index points to navigate them, as well as a working balance control or channel selector. unsurprisingly they didn't really catch on. but sound-effects & (music) sample CDs made better use of the IDs, to subdivide categories.
CDText was another red book thing that only a few bothered with. I've got some commercial titles with it (bob dylan, notably) but mostly I put it on discs I mastered myself, or else rehearsal/listening discs where I'd put comments for my guitarist, knowing that they'd pop up & surprise him on his car stereo. this player, a rather nice kenwood job, perished with his first lotus elise, which burned to the ground on the M60 one saturday afternoon. I'd heard news on 5-live of this car fire just before he texted me with the same news.

Sebastian Cobb

Yeah, my dad got a Kenwood 200 disc carousel and the cd text on most were non-existent and truncated and upper caps on the rest.

He also had a CD-I, now that thing was a waste of time. Although I do remember being amazed by the full-motion Mad Dog Mcree.

a duncandisorderly

Quote from: Sebastian Cobb on July 13, 2018, 07:30:24 PM
Yeah, my dad got a Kenwood 200 disc carousel and the cd text on most were non-existent and truncated and upper caps on the rest.


I have four of the sony 400-disc jobs. I used to leave them on shuffle & stream them to my desk at work. when I realised that I didn't know what it was playing, I added an old dv-cam & a slingbox, so I could watch them too. the video lagged by about twenty seconds, so that's how long I had to figure out or guess which one of my own CDs I was hearing. much more fun than an ipod.

Sebastian Cobb

Quote from: a duncandisorderly on July 13, 2018, 07:35:44 PM
I have four of the sony 400-disc jobs. I used to leave them on shuffle & stream them to my desk at work. when I realised that I didn't know what it was playing, I added an old dv-cam & a slingbox, so I could watch them too. the video lagged by about twenty seconds, so that's how long I had to figure out or guess which one of my own CDs I was hearing. much more fun than an ipod.

A few years ago I kept blagging reasons to work from home so I could rip my cd's to flac.

Chucked them all in google music so I can stream them anywhere. It's got an 'instant mix' feature where you point it at a track and makes you a perpetual playlist of similar tracks. It's great.

Cuntbeaks

I had that Index feature on a Pioneer Stable Platter CD player and the only CD it had any use with was Faust Tapes, which on any other CD player was just one track, one track of frightening and hallucinatory intensity. The index feature allowed you to skip through the different 'movements'.

Worth it for that alone.

Sebastian Cobb

Is the 'stable platter' deck the one where you had to put the cd in upside down as it dropped a big weight on the deck to stop the cd wobbling?

The guy I bought my Linn Kans off started pitching that to me. And some mad pioneer amp with two seperate monoblocks in it. I told him I'd got a quad 33/303 and he said 'yeah fair enough'.

Cuntbeaks

Yeah, upside right enough. The main issue was that you never got see any of the CD art as it generally got put it back into the case upside-down as well.