Forgotten audio formats: Wire recording

From espionage to home recording, the colourful life of the longest-used audio medium.

Read the whole story

 

[masterofninja]

Brilliant article! This is what I love about Ars. I was interested to hear about the "The Live Wire" album, and the restoration process. I'm going to have to have a Google (other search engines available) day to read about how they did it, as it seems that whoever's restored it is due more than a Grammy. Even the Wikipedia page only gives a passing mention to it, whereas it seems a more "exotic" method of extraction was used which must be good for digital archaeology. This must be great to try and get better sound out of old recordings - I particularly like the story of the 19th century recordings of Otto von Bismarck singing the Marseillaise.

 

[charltjr]

Love this sort of "lost tech" piece, more please.......

Techmoan did a really interesting video on a wire recorder (well, I thought it was interesting )

https://youtu.be/90ihiTwJPCc

 

[fragile]

bongbong[/url]":1d4cfzd3]is it really accurate to call wire recording or tape or vinyl, an audio format?
Im not trying to sound smart alecky or be a nitpicker.
but is this the proper form so i can use it without error since the audio formats i know are flac, wav ,mp3 etc which I KNOW are file fomats.
wont audio device be a better term?

BTW their recovery methods are brilliant and awe inspiring

I think it is accurate.

Coming from an era where everything was analogue, be it reel-to-reel tape, cassette tape, records etc, then this is definitely a format.

You are really thinking about file format - which simply does not apply in this instance as far as I can tell.

 

[jerminator]

Very interesting read on a technology that I've seen in old movies, and didn't think it was quite this ubiquitous. Good stuff. I liked the Guthrie guitar sticker "This machine kills fascists." We'll be seeing more of that sentiment soon again looking at where we're all headed.

 

[Jim Salter]

bongbong[/url]":3m3ugcn2]is it really accurate to call wire recording or tape or vinyl, an audio format?
Im not trying to sound smart alecky or be a nitpicker.
but is this the proper form so i can use it without error since the audio formats i know are flac, wav ,mp3 etc which I KNOW are file fomats.
wont audio device be a better term?

If you absolutely must nitpick this, the term you're looking for is "media" - or, in the singular, medium.

 

[AFP]

Re: the video clip showing a wire recorder in "The Two Jakes". Watch a few seconds past the wire recorder, and you also get a nice glimpse at another recording medium of days-past, instant cameras (although, given that there's a lot of overlap between photographers and people who love anachronistic things, you can still buy instant cameras and the stuff to feed them).

 

[Wardatrigger]

charltjr[/url]":25gwpc2q]Love this sort of "lost tech" piece, more please.......

Techmoan did a really interesting video on a wire recorder (well, I thought it was interesting )

https://youtu.be/90ihiTwJPCc

And in a couple more months, Ars will cover music for oscilloscopes.

 

[cbreak]

bongbong[/url]":26pc9tyw]is it really accurate to call wire recording or tape or vinyl, an audio format?
Im not trying to sound smart alecky or be a nitpicker.
but is this the proper form so i can use it without error since the audio formats i know are flac, wav ,mp3 etc which I KNOW are file fomats.
wont audio device be a better term?

BTW their recovery methods are brilliant and awe inspiring

The article doesn't actually describe the format, unfortunately, but there certainly is a way in which the data is encoded.

 

[Jim Salter]

fragile[/url]":3pjvfv7y]Coming from an era where everything was analogue, be it reel-to-reel tape, cassette tape, records etc, then this is definitely a format.

Digging back in memory, I think what audio engineers used to call "format" in the analog days wasn't ever really a tightly-defined term. It generally encompassed physical medium, encoding, and modulation in one all-encompassing if somewhat vague term - because you never really had much call to separate the layers back then; they all went together.

For that matter, the "encoding" was usually "none whatsoever" when it came right down to it. Wire or tape are both direct modulation of a magnetic medium with no encoding. Phonograph is direct modulation of a physical medium with no encoding.

 

[Jim Salter]

cbreak[/url]":14hmupog]The article doesn't actually describe the format, unfortunately, but there certainly is a way in which the data is encoded.

No, there isn't. It's direct amplitude modulation. There's no encoding whatsoever.

An example of encoding would be the old "eight, none, and one" of telephone modem days - referring to eight signal bits, no parity bit, one stop bit. There's absolutely none of that in wire, tape, phonograph, or AM radio - you literally just translate the amplitude modulation of the medium directly into movement of a speaker driver, and presto, you get sound.

It's arguable whether you could constitute FM radio as "encoded" or not - the amplitude modulation of the recorded sound is translated into frequency modulation of a carrier signal, but there's still no encoding to interpret around it, it's just the direct waveform of the original sound on an underlying medium.

 

[cbreak]

Jim Salter[/url]":35axktf4]

cbreak[/url]":35axktf4]The article doesn't actually describe the format, unfortunately, but there certainly is a way in which the data is encoded.

No, there isn't. It's direct amplitude modulation. There's no encoding whatsoever.

An example of encoding would be the old "eight, none, and one" of telephone modem days - referring to eight signal bits, no parity bit, one stop bit. There's absolutely none of that in wire, tape, phonograph, or AM radio - you literally just translate the amplitude modulation of the medium directly into movement of a speaker driver, and presto, you get sound.

It's arguable whether you could constitute FM radio as "encoded" or not - the amplitude modulation of the recorded sound is translated into frequency modulation of a carrier signal, but there's still no encoding to interpret around it, it's just the direct waveform of the original sound on an underlying medium.

Amplitude modulation IS an encoding. Not every encoding is digital.

 

[cbreak]

I would have expected "Wire Tap" to come from tapping the wires of a phone / telegraph / whatever.

 

[AFP]

cbreak[/url]":1ea0ss0k]I would have expected "Wire Tap" to come from tapping the wires of a phone / telegraph / whatever.

Perhaps this is where the expression "wearing a wire" comes from.

 

[Hat Monster]

bongbong[/url]":3385tf50]is it really accurate to call wire recording or tape or vinyl, an audio format?
Im not trying to sound smart alecky or be a nitpicker.
but is this the proper form so i can use it without error since the audio formats i know are flac, wav ,mp3 etc which I KNOW are file fomats.
wont audio device be a better term?

BTW their recovery methods are brilliant and awe inspiring

Yes, it is accurate!

The "formats" you list aren't formats at all. They're all ways to store linear PCM data. FLAC is a lossless way to store linear PCM. MP3 is a lossy way to store linear PCM. WAV is just straight up linear PCM inside a RIFF container (which is a derivation of the CBM/EA IFF container format).

The actual audio format in all cases is linear PCM.

 

[durindana]

cbreak[/url]":3ndrfq2n]I would have expected "Wire Tap" to come from tapping the wires of a phone / telegraph / whatever.

It did.

 

[Jim Z]

I've got to say, considering the medium and the condition they said it was in, they did an incredible job reclaiming the audio of "Dead or Alive."

 

[Fixpir]

Jim Salter[/url]":3r1bzikb]

fragile[/url]":3r1bzikb]Coming from an era where everything was analogue, be it reel-to-reel tape, cassette tape, records etc, then this is definitely a format.

Digging back in memory, I think what audio engineers used to call "format" in the analog days wasn't ever really a tightly-defined term. It generally encompassed physical medium, encoding, and modulation in one all-encompassing if somewhat vague term - because you never really had much call to separate the layers back then; they all went together.

For that matter, the "encoding" was usually "none whatsoever" when it came right down to it. Wire or tape are both direct modulation of a magnetic medium with no encoding. Phonograph is direct modulation of a physical medium with no encoding.

Direct modulation with a bias, as stated in the article. Or else, the hysteresis curve of the magnetic material introduces an awful distortion.
My understanding is that they did not find any remnant of HF (understand in the context "over 20kHz!") bias, on the wire, because the wire recording used DC bias. Great explanation here.
Compact cassettes and tape recorders used AC bias.

Spoiler

Without bias

With DC bias :

With AC bias :

 

[TheFritz]

I work at a company, Fort Wayne Metals, that used to manufacture this wire. I've got to briefly play around with a old play back device.

Cool stuff.

The company obviously doesn't make that wire anymore, per se. Instead, we've taken that expertise of making high quality, fine wire to make medical grade wire.

 

[Jim Salter]

cbreak[/url]":3hfinrv0]Amplitude modulation IS an encoding. Not every encoding is digital.

No, it really isn't - amplitude modulation is exactly what it says on the tin - modulation. The only way to label what goes on in wire, phonograph, or standard two-channel cassette "encoding" is if you want to get super pedantic and call it "direct" encoding - the equivalent of multiplying a number by one.

Encoding is something above and beyond the original data, which needs to be interpreted or decoded rather than being just blindly played back as part of the main data stream. And no, that doesn't need to be digital - an analog example is the old Dolby Pro Logic encoding that hid an extra couple of channels inside a two-channel recording medium.

Edit: I forgot about recording bias to tape, as pointed out above. Bias would qualify as extremely simple encoding.

 

[Hat Monster]

cbreak[/url]":29gtuevb]

Jim Salter[/url]":29gtuevb]

cbreak[/url]":29gtuevb]The article doesn't actually describe the format, unfortunately, but there certainly is a way in which the data is encoded.

No, there isn't. It's direct amplitude modulation. There's no encoding whatsoever.

An example of encoding would be the old "eight, none, and one" of telephone modem days - referring to eight signal bits, no parity bit, one stop bit. There's absolutely none of that in wire, tape, phonograph, or AM radio - you literally just translate the amplitude modulation of the medium directly into movement of a speaker driver, and presto, you get sound.

It's arguable whether you could constitute FM radio as "encoded" or not - the amplitude modulation of the recorded sound is translated into frequency modulation of a carrier signal, but there's still no encoding to interpret around it, it's just the direct waveform of the original sound on an underlying medium.

Amplitude modulation IS an encoding. Not every encoding is digital.

AM isn't an encoding, it's a modulation. You can have both, but you must have the modulation (modulation is how a different medium is changed to accept the signal: If you do no more than that, you haven't encoded anything). An encoding, as the name suggests, translates the signal into another form where it's a symbolic representation of the original. FM and AM are both not encodings, they're direct transfers into another medium. The offset of the signal controls the power of the AM signal, or the offset of the FM signal, directly.

A very simple encoding would be something like PWM, where the length of the pulse represents the power of the signal. You'd think that's a digital form, but it's still analog: The length of the pulses is your analog component. This can be demodulated by nothing more complex than a speaker cone's inertia, so represents a form of encoding and modulation where the act of demodulation is also the act of decoding.

Another common, and simple, encoding is the digitisation and capture of the signal into a digital form, such as LPCM. LPCM is just a long list of numbers, so it's a valid encoding. Being a storage, rather than transmission, format, it has no modulation.

A more complex encoding is a QAM constellation, where each state of the modulation can be one of 4, 16, 64, 256 or even more states, encoding bits into each individual state (it's similar to a look-up table, and uses one).

 

[redtomato]

cbreak[/url]":1aebafrc]

Jim Salter[/url]":1aebafrc]

cbreak[/url]":1aebafrc]The article doesn't actually describe the format, unfortunately, but there certainly is a way in which the data is encoded.

No, there isn't. It's direct amplitude modulation. There's no encoding whatsoever.

An example of encoding would be the old "eight, none, and one" of telephone modem days - referring to eight signal bits, no parity bit, one stop bit. There's absolutely none of that in wire, tape, phonograph, or AM radio - you literally just translate the amplitude modulation of the medium directly into movement of a speaker driver, and presto, you get sound.

It's arguable whether you could constitute FM radio as "encoded" or not - the amplitude modulation of the recorded sound is translated into frequency modulation of a carrier signal, but there's still no encoding to interpret around it, it's just the direct waveform of the original sound on an underlying medium.

Amplitude modulation IS an encoding. Not every encoding is digital.

From my perspective, written English is an encoding of spoken English, in that there is little direct relationship between the spoken sounds and the written graphemes. More properly, written English is a notation system, one that is full of irregularities, exemptions, and special cases.

This isn't always the case in other languages, some of which have been reformed so that most words (but still not usually every single word) can be spoken as they are written.

On a more philosophical level, all languages can be regarded as domain specific encodings of the speaker's thoughts, that require years of training to decode.

 

[Carewolf]

Jim Salter[/url]":6xo1rl8n]

cbreak[/url]":6xo1rl8n]The article doesn't actually describe the format, unfortunately, but there certainly is a way in which the data is encoded.

No, there isn't. It's direct amplitude modulation. There's no encoding whatsoever.

Well directly storing as a magnetic signal is an encoding. Plus there is the speed, which is an important part of analogue formats like this, and mentioned in the article, in fact as a form of encoded messages

 

[mmiller7]

I was watching a video about the wire recorder just the other day on YouTube...really cool stuff!
Retro Tech: The Wire Recorder

 

[Stevelane]

The thing I remember most about wire recorders was as a boy discovering spools of fine wire in a shed in the garden together with other electronic "junk". Then realizing the impossibility of getting the stuff back on the spool when it inevitably spilled off! My Dad was not best pleased!!

 

[Coriolanus]

There was an episode of Bones where some guy who was part of a Hoover-era conspiracy within the FBI had a piece of wire from a wire recorder containing JFK and a mistress. That's pretty much where I heard of wire recorders from.

 

[Jozsi]

I had no idea that wire recorders had such a long and complex history. In the early sixties a friend of mine a few years older than me had acquired one of these machines and I've never forgotten how bad it sounded. It was simply dreadful with a great deal of distortion and noise, completely unsuitable for almost anything but perhaps adequate for dictation which I imagine was its original purpose. I don't recall the recording wire itself being terribly fine but like I said, it's been a while.

 

[avilhelmo]

Any sufficiently advanced mathematics is indistinguishable from magic.

I think the Pythagoreans were right. Amazing.

 

[Rookie_MIB]

Ah - now this explains something I read about a while back. I was reading a book and there was a reference to a 'wire recording', and I just assumed that it was a 'tape recorder wired in'. I never knew that this was how they used to do older recordings...

And of course it makes sense, and you learn something new every day.

 

[Danathar]

I wonder, was there ever an attempt to do digital recording onto a wire? Something incredibly long lasting might be useful somehow.

I'd imagine the bitrate would be pathetically low by today's standards, but with enough wire you could record something digitally and archive it for a VERY long time.

 

[Coriolanus]

Danathar[/url]":qlkab2gb]I wonder, was there ever an attempt to do digital recording onto a wire? Something incredibly long lasting might be useful somehow.

I'd imagine the bitrate would be pathetically low by today's standards, but with enough wire you could record something digitally and archive it for a VERY long time.

I always thought the benefit of analog is that it degrades relatively gracefully. If you had an antenna and you were trying to pull in a TV station from far away that is analog, then you might get a lot of static and snow, but you'll still get a recognizable picture and sound.

But if you have a digital signal, if it degrades beyond a certain point, you've got nothing. So, maybe storing digital recordings onto wire might be okay initially, but as it degrades, it'll just turn into junk.

 

[Peevester]

Wardatrigger[/url]":1y4y944x]

charltjr[/url]":1y4y944x]Love this sort of "lost tech" piece, more please.......

Techmoan did a really interesting video on a wire recorder (well, I thought it was interesting )

https://youtu.be/90ihiTwJPCc

And in a couple more months, Ars will cover music for oscilloscopes.

Which is currently going nuts on youtube - search for Jerobeam Fenderson.

I'm listening to one of the Guthrie songs in the background, and it's giving me chills hearing a 60 year old recording that sounds that good. Does anyone have a link to the uncorrected audio?

 

[flashback_rtk]

a home-recording medium that people could, and did, use to record their own voices, as well as their own music and songs off the radio—thus giving the world its first example of illegal home recording.

Was there any law preventing it at the time? You make it sound as if it was the first observation of a natural phenomenon in a laboratory.

The less complicated tape decks were also getting cheaper and soon became the recorder of choice for universities, schools, independent studios, and, eventually, home recordists who fancied stealing sounds from the radio.

And that's why I ask, insisting on it makes me think you're just trying to educate your readers on your opinion on recording songs from the radio.

It was a very interesting article by the way.

 

[SPCagigas]

Nate the great[/url]":2bfdqtp0]Speaking of audio formats, whatever happened to the updog format?

... still waiting for the inevitable response...

 

[Antron Argaiv]

jerminator[/url]":14rmyxi3]Very interesting read on a technology that I've seen in old movies, and didn't think it was quite this ubiquitous. Good stuff. I liked the Guthrie guitar sticker "This machine kills fascists." We'll be seeing more of that sentiment soon again looking at where we're all headed.

The Guthries are a national treasure.

 

[Umbaglo]

Is this format what was being referred to by all my old tape players that had a switch for various tape formats that included "Metal" as one of them? I don't remember ever seeing any alternate tape format at the time, but I remember thinking "Metal" was certainly a strange one specifically.

 

[Peevester]

Umbaglo[/url]":i72cw7qu]Is this format what was being referred to by all my old tape players that had a switch for various tape formats that included "Metal" as one of them? I don't remember ever seeing any alternate tape format at the time, but I remember thinking "Metal" was certainly a strange one specifically.

No, metal is Chromium Oxide tapes, nothing to do with wire recording. A wire recording looks like a big spool of shiny thread, and is not in a cassette.