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02-09-2015, 12:29 PM
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#1
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Human being with feelings
Join Date: Sep 2008
Location: Sweden
Posts: 7,416
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Why the 100 Hz...?
A thing that has always puzzled me, but that I have not dared to ask before:
CD sampling is at 44 100 Hz, right? But why the extra 100 Hz? Would 44 kHz not have been good enough? After all, it allows to capture frequencies up to 22 kHz, and very few (*very*few*) people hear anything up there. So... why the 100 Hz...?
__________________
// MVHMF
I never always did the right thing, but all I did wasn't wrong...
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02-09-2015, 12:37 PM
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#2
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Human being with feelings
Join Date: Jun 2008
Posts: 126
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__________________
OS X 10.12.3/Win 8.1 - Late 2011 17" macbook pro.
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02-09-2015, 12:42 PM
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#3
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Human being with feelings
Join Date: Nov 2013
Location: Hamburg
Posts: 749
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Boy, I think i can start with some faint memories from the 80s. I think it has something to do with videospecs. The mastering was done with Sony PCM1630 Videomachines and video lines, frame rate and bits per line dictated the Samplingfrequency.
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02-09-2015, 12:45 PM
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#4
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Human being with feelings
Join Date: Feb 2014
Posts: 253
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According to a different article at Wikipedia, 44100/16 was...
"Originally chosen by Sony because it could be recorded on modified video equipment running at either 25 frames per second (PAL) or 30 frame/s (using an NTSC monochrome video recorder) and cover the 20 kHz bandwidth thought necessary to match professional analog recording equipment of the time."
http://en.wikipedia.org/wiki/Samplin..._processing%29
There may be other reasons too, but I haven't looked any farther.
:-Don
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02-09-2015, 12:55 PM
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#5
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Banned
Join Date: Dec 2011
Location: Oud West, NL
Posts: 2,335
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As usual, it's SONY's fault. But let's not forget, the old BETA tapes were so much better than VHS ... meaning SONY gets one good idea and it gets crushed by the hoards.
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02-09-2015, 03:10 PM
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#6
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Human being with feelings
Join Date: Sep 2008
Location: Sweden
Posts: 7,416
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Quote:
Originally Posted by HobbyCore
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Ah! Of course... Thanks.
And, yes, it certainly has something to do with video specs:
Code:
It is simplest if the same number of lines are used in each field, and,
crucially, it was decided that a sample rate that could be used on both
NTSC (monochrome) and PAL equipment. Since NTSC has a field rate of 60
Hz, and PAL has a field rate of 50 Hz, their least common multiple is
300 Hz, and with 3 samples per line, this yields a sample rate that is
a multiple of 900 Hz. For NTSC the sample rate is 5m × 60 × 3, where 5m
is the number of active lines per field, which must be a multiple of 5
(the rest used for synchronization), and for PAL the sample rate is 6n
× 50 × 3, where 6n is the number of active lines per field, which must
be a multiple of 6. The sampling rates that satisfy these requirements
– at least 40 kHz (so can encode 20 kHz sounds), no more than 46.875
kHz (so require no more than 3 samples per line in PAL), and a multiple
of 900 Hz (so can be encoded in NTSC and PAL) are thus 40.5, 41.4,
42.3, 43.2, 44.1, 45, 45.9, and 46.8 kHz. The lower ones are eliminated
due to low-pass filters requiring a transition band, while the higher
ones are eliminated due to some lines being required for vertical
blanking interval; 44.1 kHz was the higher usable rate, and was
eventually chosen.
__________________
// MVHMF
I never always did the right thing, but all I did wasn't wrong...
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02-09-2015, 04:47 PM
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#7
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Human being with feelings
Join Date: Oct 2007
Location: Lincoln, UK
Posts: 7,924
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Quote:
Originally Posted by The Telenator
As usual, it's SONY's fault. But let's not forget, the old BETA tapes were so much better than VHS ... meaning SONY gets one good idea and it gets crushed by the hoards.
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Don't forget, they held out for 16-bit when others said only 14-bit was required. Imagine the sample-rate/ bit-depth threads if that had been the CD standard
>
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02-09-2015, 07:16 PM
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#8
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Human being with feelings
Join Date: Jan 2009
Location: New Zealand
Posts: 2,905
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Sony has been a pretty amazing firm when you think about it.
They have done lots of development over the years.
Grinder
https://soundcloud.com/steve-maitland-1
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02-09-2015, 08:46 PM
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#9
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Human being with feelings
Join Date: Mar 2010
Location: Adelaide, South Australia (originally from Geelong)
Posts: 5,598
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Quote:
Originally Posted by grinder
Sony has been a pretty amazing firm when you think about it.
They have done lots of development over the years.
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Indeed. In fact, the S/Pdif protocol many of us use actually stands for Sony/Philips Digital Interconnect Format.
Philips are also another company that have been pivotal in the digital revolution. They were pioneers in the development of the Compact Disc format. I still have a first generation Philips CD player here.
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02-09-2015, 09:15 PM
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#10
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Human being with feelings
Join Date: Jul 2010
Location: Online
Posts: 4,896
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It Hz so good it can't be bad?
__________________
it aint worth a bop,if it dont got that pop
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02-09-2015, 10:05 PM
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#11
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Human being with feelings
Join Date: Jul 2010
Location: Online
Posts: 4,896
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Quote:
Originally Posted by The Telenator
As usual, it's SONY's fault. But let's not forget, the old BETA tapes were so much better than VHS ... meaning SONY gets one good idea and it gets crushed by the hoards.
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yeah betamax was fucking brilliant.
I had a copy of Live In Pompei and Quadrophenia both on betamax.
The sound was fantastic.
I threw them all in a skip in 1992
__________________
it aint worth a bop,if it dont got that pop
Last edited by Cosmic; 02-09-2015 at 11:13 PM.
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02-09-2015, 11:11 PM
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#12
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Human being with feelings
Join Date: Aug 2011
Posts: 668
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Quote:
Originally Posted by Fabian
Ah! Of course... Thanks.
And, yes, it certainly has something to do with video specs:
Code:
It is simplest if the same number of lines are used in each field, and,
crucially, it was decided that a sample rate that could be used on both
NTSC (monochrome) and PAL equipment. Since NTSC has a field rate of 60
Hz, and PAL has a field rate of 50 Hz, their least common multiple is
300 Hz, and with 3 samples per line, this yields a sample rate that is
a multiple of 900 Hz. For NTSC the sample rate is 5m × 60 × 3, where 5m
is the number of active lines per field, which must be a multiple of 5
(the rest used for synchronization), and for PAL the sample rate is 6n
× 50 × 3, where 6n is the number of active lines per field, which must
be a multiple of 6. The sampling rates that satisfy these requirements
– at least 40 kHz (so can encode 20 kHz sounds), no more than 46.875
kHz (so require no more than 3 samples per line in PAL), and a multiple
of 900 Hz (so can be encoded in NTSC and PAL) are thus 40.5, 41.4,
42.3, 43.2, 44.1, 45, 45.9, and 46.8 kHz. The lower ones are eliminated
due to low-pass filters requiring a transition band, while the higher
ones are eliminated due to some lines being required for vertical
blanking interval; 44.1 kHz was the higher usable rate, and was
eventually chosen.
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I am so glad I know all that now.
I mean not glad. I am not glad.
__________________
~~~ Proud Reaper License Owner! ~~~
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02-09-2015, 11:19 PM
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#13
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Human being with feelings
Join Date: Feb 2013
Location: Northeast Michigan
Posts: 3,460
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Quote:
Originally Posted by Fabian
Ah! Of course... Thanks.
And, yes, it certainly has something to do with video specs:
Code:
It is simplest if the same number of lines are used in each field, and,
crucially, it was decided that a sample rate that could be used on both
NTSC (monochrome) and PAL equipment. Since NTSC has a field rate of 60
Hz, and PAL has a field rate of 50 Hz, their least common multiple is
300 Hz, and with 3 samples per line, this yields a sample rate that is
a multiple of 900 Hz. For NTSC the sample rate is 5m × 60 × 3, where 5m
is the number of active lines per field, which must be a multiple of 5
(the rest used for synchronization), and for PAL the sample rate is 6n
× 50 × 3, where 6n is the number of active lines per field, which must
be a multiple of 6. The sampling rates that satisfy these requirements
– at least 40 kHz (so can encode 20 kHz sounds), no more than 46.875
kHz (so require no more than 3 samples per line in PAL), and a multiple
of 900 Hz (so can be encoded in NTSC and PAL) are thus 40.5, 41.4,
42.3, 43.2, 44.1, 45, 45.9, and 46.8 kHz. The lower ones are eliminated
due to low-pass filters requiring a transition band, while the higher
ones are eliminated due to some lines being required for vertical
blanking interval; 44.1 kHz was the higher usable rate, and was
eventually chosen.
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Is that math? It looks like math... oooooh my head hurts...
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02-10-2015, 12:49 AM
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#14
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Human being with feelings
Join Date: Mar 2008
Location: Unwired (probably in the proximity of Amsterdam)
Posts: 4,868
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Quote:
Originally Posted by The Telenator
As usual, it's SONY's fault. But let's not forget, the old BETA tapes were so much better than VHS ... meaning SONY gets one good idea and it gets crushed by the hoards.
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You must have been watching only pr0n tapes, then - Philips' V2000 was technically better, it just didn't have pr0n available, courtesy of its Christian board of directors (crushed by the boards ). And everybody *hated* having to flip the tape halfway the movie - except people watching pr0n who usually didn't get that far in a single viewing.
__________________
˙lɐd 'ʎɐʍ ƃuoɹʍ ǝɥʇ ǝɔıʌǝp ʇɐɥʇ ƃuıploɥ ǝɹ,noʎ
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02-10-2015, 12:58 AM
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#15
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Human being with feelings
Join Date: Mar 2008
Location: Unwired (probably in the proximity of Amsterdam)
Posts: 4,868
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Quote:
Originally Posted by grinder
Sony has been a pretty amazing firm when you think about it.
They have done lots of development over the years.
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At that point, Sony was great at marketing and design, but really sucked at developing technology. Remember how they sold "walkmans" - which Philips had invented (but called "portable compact cassette player"). After both Philips and Sony had lost the video standard war, they teamed up to redeploy Philips' existing LaserDisc technology under a new name, Compact Disc (also see S/PDIF: Sony/Philips digital interface.)
Then both firms failed big time again, when Apple - a company without any music tech nor a huge music publishing rights catalog - showed them how to design and market sell portable music players. Amazing, indeed.
__________________
˙lɐd 'ʎɐʍ ƃuoɹʍ ǝɥʇ ǝɔıʌǝp ʇɐɥʇ ƃuıploɥ ǝɹ,noʎ
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02-10-2015, 01:29 AM
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#16
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Human being with feelings
Join Date: Mar 2010
Location: Adelaide, South Australia (originally from Geelong)
Posts: 5,598
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Quote:
Originally Posted by Banned
......After both Philips and Sony had lost the video standard war, they teamed up to redeploy Philips' existing LaserDisc technology under a new name, Compact Disc (also see S/PDIF: Sony/Philips digital interface.)
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I posted about that a few posts up.
Quote:
Originally Posted by ReaDave
Indeed. In fact, the S/Pdif protocol many of us use actually stands for Sony/Philips Digital Interconnect Format.
Philips are also another company that have been pivotal in the digital revolution. They were pioneers in the development of the Compact Disc format. I still have a first generation Philips CD player here.
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02-10-2015, 03:23 AM
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#17
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Human being with feelings
Join Date: Mar 2008
Location: Unwired (probably in the proximity of Amsterdam)
Posts: 4,868
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Quote:
Originally Posted by ReaDave
I posted about that a few posts up.
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Ah yes, missed that bit. The point I wanted to make here is that - oversimplified a bit - Sony didn't really put in much useful technological expertise, that was mainly Philips' contribution. But Philips sucked at marketing and design (LD, V2000 flops; Sony outselling them on 'walkmans'), where Sony did a much better job at that point in time. They joined forces mainly because sufficient critical mass (market share) is needed to set a new standard; both firms were big players in music publishing too, and they used a very liberal licensing scheme so everony could build cheap CD players (royalties were set at less than a dollar per CD player, iirc).
__________________
˙lɐd 'ʎɐʍ ƃuoɹʍ ǝɥʇ ǝɔıʌǝp ʇɐɥʇ ƃuıploɥ ǝɹ,noʎ
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02-10-2015, 07:34 AM
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#18
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Human being with feelings
Join Date: May 2011
Posts: 2,694
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Quote:
Originally Posted by Cosmic
yeah betamax was fucking brilliant.
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Indeed. Remember the portable F1 ? which IIRC could be used for pcm audio. Also it could be simply slotted into a pro edit suite and be used directly as a source machine.
Still have a beta tape somewhere. oh the memories.
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02-10-2015, 01:15 PM
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#19
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Human being with feelings
Join Date: Sep 2008
Location: Sweden
Posts: 7,416
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Quote:
Originally Posted by Jeffsounds
Is that math? It looks like math... oooooh my head hurts...
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Math is good...
__________________
// MVHMF
I never always did the right thing, but all I did wasn't wrong...
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02-10-2015, 03:50 PM
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#20
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Human being with feelings
Join Date: Feb 2013
Location: Northeast Michigan
Posts: 3,460
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Quote:
Originally Posted by Fabian
Math is good...
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BLASPHEMER!
Actually I rather enjoyed math in school, especially algebra. I remember algebra being quite fun in college but we had this really cool prof who was GREAT at teaching his subject!
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02-11-2015, 11:57 AM
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#21
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Human being with feelings
Join Date: Sep 2008
Location: Sweden
Posts: 7,416
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Quote:
Originally Posted by Jeffsounds
BLASPHEMER!
Actually I rather enjoyed math in school, especially algebra. I remember algebra being quite fun in college but we had this really cool prof who was GREAT at teaching his subject!
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Yes, that matters... a lot. Unfortunately, the way math is taught in schools is (typically) not good...
__________________
// MVHMF
I never always did the right thing, but all I did wasn't wrong...
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02-11-2015, 12:03 PM
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#22
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Human being with feelings
Join Date: Oct 2008
Posts: 1,598
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Quote:
Originally Posted by The Telenator
As usual, it's SONY's fault. But let's not forget, the old BETA tapes were so much better than VHS ... meaning SONY gets one good idea and it gets crushed by the hoards.
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I've heard this. how are Beta tapes better than VHS though? just curious
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