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Burn your own Frequency Waveform CD (1 Viewer)

Tom.le

Agent
Joined
Jul 9, 2002
Messages
34
http://www.geocities.com/frequency_wave/
Here are a few CDRs I've made. I hope some people find them useful.
They're great for speaker phase rotation and audio equipment calibration.
Burn your own frequency CDR from 1Hz to 22kHz either sine wave or square wave.
Remember, all files are actually .ACE compressed (WinAce). You must rename the .ACE.ZIP extensions to .ACE. Geocities does not support .ACE files, that's why they had to be named .zip.
 

PaulT

Supporting Actor
Joined
Oct 28, 2002
Messages
932
Tom,

Thanks for the access to the files. Just to let everyone know, Geocities has a bandwidth limitation on downloads, so you might have to wait another hour if the site gets hit a lot. I was able to get 3 files before hitting the limit.
 

Tom.le

Agent
Joined
Jul 9, 2002
Messages
34
Thanks for the feedback Paul.

What a rip. I wonder if I could place them elsewhere where there's no limit, or at least a lot higher.
 

Bob McElfresh

Senior HTF Member
Joined
May 22, 1999
Messages
5,182
The NCH Tone Generator is also useful. You pick the frequency & duration and it writes a .WAV file. Each wave file becomes a track on your own custom cd. You can make one for octave frequencies to measure subwoofer response in your room.
 

Christ Reynolds

Senior HTF Member
Joined
May 6, 2002
Messages
3,597
Real Name
CJ
just out of curiosity, how is it that i can download a 788kb file and have it decompress to 746 mb? the compressed ACE files are 12.48mb, and the decompressed cd images are 7.17gb. seems like quite a ratio to me.

CJ
 

PaulT

Supporting Actor
Joined
Oct 28, 2002
Messages
932
There is a huge redundancy in information contained in the sine waves. This allows the amount of compression you see with WinAce or WinZip or WinRar. They are all using slightly different algorithms, but the more redundancy, the smaller the resulting files.
Here is a link to very basic File Compression info:
http://www.howstuffworks.com/file-compression.htm
 

Tom.le

Agent
Joined
Jul 9, 2002
Messages
34
And the better algorithm the better the compression. Which is why I chose the .ACE compression for my distribution. I tried .RAR, but it compressed to about 75MB. I tried .ZIP, but I forgot what it compressed to, I think it was in the hundreds range.

Somehow, .ACE compression can recognize a really quick redundancy. Which is what is involved in a sinewave. For example, a 60Hz tone sinewave repeats after almost 0.017 seconds. So, make an algorithm to see the pattern of 0.017 seconds in a length of 1.0 minute or higher, and you got yourself compression.

Each compressor has their own advantages. .ACE (Winace) just happens to be the best for redundant sine and square waves. As I've said, I've tried the others, and only .ACE has been able to compress 746MB to 1.8MB (414 times!).
 

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