The Traders' Den  

  The Traders' Den > Where we go to learn ..... > Technobabble
 

Notices

Technobabble Post your general Need for Help questions here.
Lossy or Lossless?
Moderators

Reply
 
Thread Tools
  #1  
Old 2005-08-09, 04:50 PM
irishcrazy2005's Avatar
irishcrazy2005 irishcrazy2005 is offline
Yeah, that's a zebra donkey
110.97 GB/130.20 GB/1.17
 
Join Date: Nov 2004
Location: Berkeley, CA
24/96 Audacity

Oops!

Last edited by irishcrazy2005; 2005-08-09 at 06:27 PM.
Reply With Quote Reply with Nested Quotes
  #2  
Old 2005-08-09, 05:29 PM
Five's Avatar
Five Five is offline
189.30 GB/594.78 GB/3.14
 
Join Date: Oct 2004
Location: Canada
Re: Adobe Audition

this isn't the sort of info you will find on this board.

you could try http://audacity.sourceforge.net/ you just have to set a few things to make it display all the way up to 22500kHz in the spectral display (in the options).

You could also seek out an old shareware version of CEP2.0 there's a link posted in the first thread in the lossy or lossless forum here. when that prog expires you are still allowed to use the spectral view and frequency analysis altho pretty much everything else won't work after it expires, unlike Adobe Audition where nothing works after it expires.
__________________
Checksums Demystified | ask for help in Technobabble

thetradersden.org | ttd recommended free software/freeware webring
shntool tlh eac foobar2000 spek audacity cdwave vlc

Quote:
Originally posted by oxymoron
Here you are in a place of permanent madness, be careful!
Reply With Quote Reply with Nested Quotes
  #3  
Old 2005-08-09, 06:08 PM
irishcrazy2005's Avatar
irishcrazy2005 irishcrazy2005 is offline
Yeah, that's a zebra donkey
110.97 GB/130.20 GB/1.17
 
Join Date: Nov 2004
Location: Berkeley, CA
Re: Adobe Audition

Quote:
Originally Posted by Five
this isn't the sort of info you will find on this board.

you could try http://audacity.sourceforge.net/ you just have to set a few things to make it display all the way up to 22500kHz in the spectral display (in the options).

You could also seek out an old shareware version of CEP2.0 there's a link posted in the first thread in the lossy or lossless forum here. when that prog expires you are still allowed to use the spectral view and frequency analysis altho pretty much everything else won't work after it expires, unlike Adobe Audition where nothing works after it expires.
Thanks for the info. I want to be clear that I wasn't trying to do anything illegal, so sorry if what I asked was!

-Phil
Reply With Quote Reply with Nested Quotes
  #4  
Old 2005-08-09, 06:29 PM
irishcrazy2005's Avatar
irishcrazy2005 irishcrazy2005 is offline
Yeah, that's a zebra donkey
110.97 GB/130.20 GB/1.17
 
Join Date: Nov 2004
Location: Berkeley, CA
Re: 24/96 Audacity

Ok, so now I am using Audacity and I have a question. I have two versions of the same show. Same source, one is just the original 24/96 seed and the other is the 16/44.1 seed that the taper also released. When opening these in Audacity and zooming into a 2-sec section, the waveforms look exactly the same. Why is this, and where should I be seeing differences?

-Phil
Reply With Quote Reply with Nested Quotes
  #5  
Old 2005-08-09, 06:38 PM
irishcrazy2005's Avatar
irishcrazy2005 irishcrazy2005 is offline
Yeah, that's a zebra donkey
110.97 GB/130.20 GB/1.17
 
Join Date: Nov 2004
Location: Berkeley, CA
Re: 24/96 Audacity

Ahha! Now I've figured it out. If you look at the FFT analysis, the 24-bit sources gets lower and higher in frequencies! I should just retitle this thread, "Thread where I talk to myself."

-Phil
Reply With Quote Reply with Nested Quotes
  #6  
Old 2005-08-10, 01:59 PM
irishcrazy2005's Avatar
irishcrazy2005 irishcrazy2005 is offline
Yeah, that's a zebra donkey
110.97 GB/130.20 GB/1.17
 
Join Date: Nov 2004
Location: Berkeley, CA
Re: 24/96 Audacity

Ok, now i am confused about some things. I understand the Nyquist theorem saying that the sampling frequency must be twice the bandwidth of the source, but I am confused by this spectrum. What are these higher frequencies in this FFT of a 24-bit, 96kHz source? Are these really acoustic frequencies being picked up by the mics, or are they just higher harmonics or something? I am confused. I didn't think that mics could pick up frequencies this high. What is the sharp cut-off at about 24kHz? Also, if I lower the FFT size, the higher frequencies all but dissappear. Help! I am so confused.....

-Phil

Reply With Quote Reply with Nested Quotes
  #7  
Old 2005-08-10, 03:14 PM
prof_peabody's Avatar
prof_peabody prof_peabody is offline
16.47 GB/136.61 GB/8.29
 
Join Date: Mar 2005
Re: 24/96 Audacity

Without much info, and my audio physics fading rapidly, it looks like the source had a hard (rectangle) high-pass filter (e.g. not tappered). This kind of filtering is great fr producing all kinds of aliasing. It looks like the energy peak at 12 kHz is generating a nice harmonic at 24 and 36 kHz.

On a side note, i wonder about the usefulness of recording 96 kHz with some mics. Seems overkill to me; 24 bit I can understand.
Reply With Quote Reply with Nested Quotes
  #8  
Old 2005-08-10, 03:20 PM
prof_peabody's Avatar
prof_peabody prof_peabody is offline
16.47 GB/136.61 GB/8.29
 
Join Date: Mar 2005
Re: 24/96 Audacity

Ok, things are starting to move in my head. It looks like someone wasted a lot of bits recording at 96 kHz. Somewhere in the set-up something is filtering the signal just above 22 kHz. The rectangle filter is introducing a fair amount of noise just below 22 kHz. If you wante to clean up the recording, I'd probably run a tapered filter on the high end to filter out that crap.
Reply With Quote Reply with Nested Quotes
Reply

The Traders' Den > Where we go to learn ..... > Technobabble

Similar Threads
Thread Forum Replies Last Post
Question about Audacity - Drgiggles1 Technobabble 14 2009-01-26 04:14 PM
Editing in Audacity - yrascals Technobabble 2 2006-04-30 07:33 PM
Audacity fade-in? - Kush Technobabble 4 2006-04-09 06:20 PM
Help with Audacity? - lepaul Technobabble 3 2006-01-09 07:57 PM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forums


All times are GMT -5. The time now is 06:55 AM.


Powered by: vBulletin, Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004 - , TheTradersDen.org - All Rights Reserved - Hosted at QuickPacket