h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Entry: Tape Hiss - A3651707
Author: Hell (Scout) - U171578

This is a short Entry Explaining what 'Tape Hiss' is. I didn't want to go into the details of how to supress tape hiss - this would be sufficient material for five other Entries (which I plan to do in the near future)

HELL

Yup. It is short. Can't argue with you there.

Just a thought - though you don't want to go into the details on hiss suppression, would you mind giving a nod in that direction, as a coda to the entry. Little more than a remark that hiss suppression methods exist would make me happy, and it would round out the entry a bit, as otherwise you could ge the impression that tape hiss is a totally insurmountable problem.


Geggs

Hi Hell,

I see your conundrum, but it leaves the entry, as is, somewhat incomplete. My immediate question was exactly the one you wanted to leave out for the time being: how is tape hiss reduced? Could you provide even a summary of the ways that hiss could be reduced even for the purposes of the article?

Otherwise it's a good, well written entry.

Woodpigeon

OK. I see...Rounding up! Good idea... I'll add a bit in a moment.

HELL

"This is also one explanation as to why the archaic, mechanic vinyl records were replaced only late in the 1980s by the digitally recorded compact discs."

I read this as "Vinyl records are better than the tapes made from them, so it was only in the late 1980s that vinyl records were replaced by digital compact discs."

I don't understand that at all.

Yeah, that's how I read it, but I didn't think there was a problem with the line. I take it you disagree?


Geggs

"CDs only replaced vinyl in the late 80s because vinyl was better than tape".

What sort of an explanation is that?

It is rather glib I guess. I suppose the longer explanation would be that because the sound quality on tape was never any better (and in some cases worse) than that of an LP, tapes were never able to replace LPs, but rather sat alongside them, as a more convenient alternative. CDs, which have noticably better sound quality, have more or less wiped out LPs, and are now the principle sound reproduction medium. Unless I've got that totally wrong.

On balance, I guess the whole argument is a little outside the main thrust of the entry.


Geggs

Cassettes are a lot more practical, require less care and you can hear them in the car. In principle, the quality of cassete recorded sound can be very good. Even so, vinyl LPs did not vanish, as they still had a better sonic quality and: no tape hiss. That's why they were not replaced or affected in any way by the invention of cassettes. I had it that there was a fear by then, that the cassette would make the vinyl LPs obsolete. Just like today you sometimes hear people saying paper print media are on the way out, because you can store the entire encyclopaedia galactica on two and a half CDs (or other numbers I dunno).

I'll tweak around with that one... Just gimme a minute!

HELL

OK, better now?

I also included a little bit about tape hiss suppression...

HELL

Nice little entry Hell

"typical high pitch noise sound"
No need for both noise *and* sound - choose which one fits the bill best and delete the other.

Is tape hiss really a 'high pitch sound'? It's a form of white noise, although it may have a bias toward the higher end of the sound spectrum. The opposite (bass-heavy white noise) is called 'pink noise'; is there a similar term for top-heavy white noise?

"In fact, tape hiss can be heard on any material that has originally been recorded to tape - that is, virtually all recordings until the late 1980s"
Sound recordings were originally made direct to cylinder or disc - tape didn't ebter the equation at all. When was tape first regularly used as a recording medium for subsequent transfer to disc? And if there was a significant period beforehand, is it correct to say 'virtually all'?

"late in the 1980s by the digitally recorded compact discs"
Same kind of question: When did digital recording start, and how many of the original CD releases were simply made from old master tapes?

"The texture of the magnetic tape that is being recorded"
The sound is being recorded, the tape is what it's being recorded on.

"The texture of the magnetic tape that is being recorded, the size and the thickness of the magnetic particle's grains that ere embedded somehow in the plastic tape produce fluctuations in the involved magnetic fields, which are later heard as a noise sound, the tape hiss"
It took me quite a few runs to understand that fully. I think I see it like this: 'Recording tape is made up of tiny grains of a magnetic substance which are fixed to the tape itself. The presence of the grains produces fluctuations in the magnetic fields involved in the initial recording, and this is later heard as a sound - tape hiss. The smaller the grains, the lower the amount of hiss'.

reverting - reversing

I don't follow the Dlby A explanation. Surely the filters *decrease* the high end during recording, and then boost it again during playback.


Scout

Dolby boosts the high frequency of the music, then records it on tape. On playback, it attenuates the high frequency, so that it is back to the correct volume relative to everything else. But in this stage of the process, the high frequency his is attenuated as well.

But if you didn't understand that, Hell should explain it better.

Wow... Thanks for your comments.

"typical high pitch noise sound"
How about 'noisy sound'?

"Is tape hiss really a 'high pitch sound'?"
Typically yes. At least the most audible and annoying part is high pitch.

"In fact, tape hiss can be heard on any material that has originally been recorded to tape - that is, virtually all recordings until the late 1980s"

"Sound recordings were originally made direct to cylinder or disc - tape didn't ebter the equation at all. When was tape first regularly used as a recording medium for subsequent transfer to disc? And if there was a significant period beforehand, is it correct to say 'virtually all'?"

I think so. Tape, or magnetic recording started around 1935. Effectively all recordings from 1935 to 1985, had some form of magnetic tape in the equation. The few recordings before that period are a interesting, but negligible percentile of recordings.

"late in the 1980s by the digitally recorded compact discs"

Digital recording was possible in the mid-80s, it became common in the mid-90. The point is - as written in the Entry, that in fact, tape hiss can be heard on any material that has originally been recorded to tape. It doesn't matter if the end product is a CD or a vinyl record, if the original piece has been recorded to tape any reproduction (the CD, in that case) will contain tape hiss.

"I think I see it like this: 'Recording tape is made up of tiny grains of a magnetic substance which are fixed to the tape itself. The presence of the grains produces fluctuations in the magnetic fields involved in the initial recording, and this is later heard as a sound - tape hiss. The smaller the grains, the lower the amount of hiss'."

Almost there. The smaller and the more homogenous(!) the grains, the lower the amount of hiss.

"I don't follow the Dlby A explanation. Surely the filters *decrease* the high end during recording, and then boost it again during playback."

Gnomon's right... (That's why I wanted to make a separate Entry about N.R.). I will try to explain this better and still keep it as short as possible!


OK... I'll bop a note when I think it's ready!

Thanks!

HELL

Here it comes...

Take a look at it now. I did some rewording, and removed some odd words from parts that didn't work well. I rephrased the DolbyA part.

HELL

Looks much better now, but I'm still uncomfortable with the phrase 'noisy sound'. All sounds are noisy since they all make a noise - an un-noisy sound would be silence. I think you can just call tape hiss a noise, since a noise a bit like a weed. A weed is simply a plant growing where you don't want that plant to be. A noise is a sound in a place you don't want that sound to be

"This is also one explanation as to why the archaic, mechanic vinyl records were not replaced by the more handy cassettes"
I was pondering this bit earlier and couldn't quite put my finger on why it didn't feel right, but now I think I've got it. An explanation of something is the whole reason why it's so, but there may be more than factor, or individual reasons in that explanation. I think it would be better to say 'This is one reason why...', because there were other reasons, such as (as far as I was concerned at the time) the tiny artwork and the fact that you can't skip from one track to the next as easily as moving the stylus from track to another on a record. You yourself give another reason later on in the entry - the fact that it's a whole lot more difficult to play records in a car as opposed to cassettes.

Interesting

Just one thing - what's a noodler?

What ever it is it sounds cool

Just flying through and read a bit

availiable>>available

Kat

On the new CD's of older recorded music, before the invention of the CD's, do you hear the tape hiss as well? If I listen to a CD of lets say a typical 50 or 60 artist, Elvis Presley, is the tape hiss noticable as well? By the way,

(I've got some tapes with recorded music dating back to the seventies and they are still sound very clear.

Cassettes are not that bad at all!!! That's why some people thought it would replace vinyl records... Tape (talkin' about reels now) were the medium of choice until very recently. When it comes to mixing, producing, equalizing and storing they're a lot more robust and versatile than shellacks or metal cylinders.

BTW. I also have some very nice sounding cassettes with 80s stuff... But on the quiet pars you hear the goddamn hiss... It's there!

I added a footnote explaining that you hear tape hiss on CDs too if the original recording was on tape.

Cheers!

HELL

PS: 'one explanation' mutated to 'one reason', and 'noisy sound' became 'noise'... You're right. It's better that way