47.967 kHz sample rate?

[Azimuth]

I was reading Bob Clearmountain's SOS article and they talk about "pulling down the sample rate to 47.967k while mixing". I've never heard such a thing, I've only known the standards sample rates (44.1, 48 and so on). Is this some kind of video option or something?

[danbronson]

Originally Posted by Azimuth

I was reading Bob Clearmountain's SOS article and they talk about "pulling down the sample rate to 47.967k while mixing". I've never heard such a thing, I've only known the standards sample rates (44.1, 48 and so on). Is this some kind of video option or something?

I'm going to go out on a limb and say that that is what 48 actually is and they just round up for simplicity's sake. But that's just a guess, I'm curious as well!

[narcoman]

Originally Posted by Azimuth

I was reading Bob Clearmountain's SOS article and they talk about "pulling down the sample rate to 47.967k while mixing". I've never heard such a thing, I've only known the standards sample rates (44.1, 48 and so on). Is this some kind of video option or something?

yup. Have to do that sort of thing all the time. Pull downs for video are common.

[theblue1]

I found these references to that precise frequency:

XFree86 on Beige Macintosh G3
Keywords:
Date Created: 2002-09-17
Author: Luke Scharf luke@vt.edu
The following is a sample /etc/X11/XF86Config-4 file that is compatible
with the Beige All-in-One Macintosh G3:
[...]
Mode "800x600"

# D: 49.885 MHz, H: 47.967 kHz, V: 72.022 Hz
DotClock 49.886
HTimings 800 856 976 1040
VTimings 600 637 643 666
Flags "+HSync" "+VSync" # Warning: XFree86 doesn't support accel
EndMode

xfree86-beige-macintosh-g3

So, it appears it may be something related to the horizontal reresh rate of an old Macintosh Beige monitor spec.

But 47.967 is also apparently the amount (in millions -- or maybe billions? -- of dollars) of some weapon system funding on a unclassified Air Force budget sheet in PDF form: www.saffm.hq.af.mil/shared/media/document/AFD-070212-005.pdf

I'm thinking it might relate to the former but the latter seems a stretch.

[larry b]

Yup, it's for video work. Similar to the Drop-Frame/Non-Drop Frame SMPTE thing.

[joeq]

Originally Posted by Mike Derrick

if ya google yer number you get the, Boltzmann constant.

it looks like you got the number times the Boltzman constant

probably the 'k' - k is used to represent a constant in physics equations

If you google 44.1k you will get audio stuff, but if you just put in any old number with a lot of decimals and with a 'k' it will give the result of that number times the Boltzman constant

[Azimuth]

Originally Posted by narcoman

yup. Have to do that sort of thing all the time. Pull downs for video are common.

Excuse my curiosity but how exactly do you do a "pull down" like that?

[Mike Derrick]

Originally Posted by joeq

it looks like you got the number times the Boltzman constant

probably the 'k' - k is used to represent a constant in physics equations

If you google 44.1k you will get audio stuff, but if you just put in any old number with a lot of decimals and with a 'k' it will give the result of that number times the Boltzman constant

You are right.

[narcoman]

Originally Posted by Azimuth

Excuse my curiosity but how exactly do you do a "pull down" like that?

personally? It's a feature in PT.

[theblue1]

Originally Posted by joeq

it looks like you got the number times the Boltzman constant

probably the 'k' - k is used to represent a constant in physics equations

If you google 44.1k you will get audio stuff, but if you just put in any old number with a lot of decimals and with a 'k' it will give the result of that number times the Boltzman constant

I knew there'd be hell to pay for dropping out of that Zen, Existentialism, and the Art & Mystery of Quantum Mechanics class...