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[Yadaraf]

OK good people...

I've just run a couple of Waves processors on the important part of the original video - generally to remove most of the multiband buzz and lift the detail a little. It's only a hi-res MP3 to limit file size from the processed WAV.

Maybe someone has got a little more time that myself to play around with it further, though hopefully will help to serve as a point of general reference. Must get some shut-eye now - work tomorrow and it's 2:25am over here !

http://www.funkyjive.com/Audio/  -  There's only one track - 9.4Mb


Chin chin 

FunkyJive

FunkyJive,

Great job on the processing.  An analyses of your soundtrack at the 1700 RPM point shows peaks that were not obvious in the original video.

Cheers, 

Yada ..
.

[blue_energy]

OK good people...

I've just run a couple of Waves processors on the important part of the original video - generally to remove most of the multiband buzz and lift the detail a little. It's only a hi-res MP3 to limit file size from the processed WAV.

Maybe someone has got a little more time that myself to play around with it further, though hopefully will help to serve as a point of general reference. Must get some shut-eye now - work tomorrow and it's 2:25am over here !

http://www.funkyjive.com/Audio/  -  There's only one track - 9.4Mb


Chin chin 

FunkyJive

That was a heroic effort, FunkyJive!  I was hoping to use the resulting wav to do the same peak measuring thing I did with Bruce's.  But - it was scrambled too much.  It's too hard for me to tell where the peaks are - too hard to identify the sine within the complex wave.  Thanks for your effort anyway!

[PolyMatrix]

The applet is a Javascript 1.1 make sure you have Java installed correctly by deleting all current installations and then installing the latest version. Sometimes the updates overload and older version and cause problems

I had no problem with it.

Here is the link for Java updates http://www.java.com/en/download/manual.jsp

Edit
That is one GREAT Javascript (Salutes the person who wrote it.)

[Yadaraf]

@Yadaraf,

Thanks for the spectral analysis. So, the characteristic frequencies in my first wave are 63Hz and 2kHz while here they are at 180Hz and 1.6kHz. I wonder if you checked the other files I submitted here just to see if the data are reproducible. Waiting to see what Bruce's data will yield.

On another note, was anyone able to open @korkscrew's applet: http://home.earthlink.net/~danniee/whipmag/WMModel.htm?

EDIT: OK, I got it. It only opens in IE, Firefox isn't its friend.

Omni,

The analysis of your soundtrack was performed at the point where your device was spinning [down] at 230 RPM.  Al's rotor would have been spinning at a constant 425 RPM -- for 1700 stator RPM.  All that I can infer at this point is that both your's and Al's devices appear to produce TWO characteristic frequencies albeit very different.


Cheers, 

Yada ..
.

[Omnibus]

@Yadaraf,

So, you took only that portion of my wave where the resonance is occurring and left the rest out, correct? Maybe you can take the initial portions of the other waves I posted here because they are at around 400rpm to see if there would be anything similar to @alsetalokin's characteristic frequencies. Too bad the rotor isn't with me (will be back from the machine shop on Tuesday, I hope) so that I can record it at 425rpm to see if the fingerprints will be the same as in the original.

Also, Bruce has a resonance portion in his wave. Would be interesting to see if it coincides with mine and how it differs from other sections without resonance (say around 425rpm as in the original).

[Yadaraf]

@Yadaraf,

So, you took only that portion of my wave where the resonance is occurring and left the rest out, correct? Maybe you can take the initial portions of the other waves I posted here because they are at around 400rpm to see if there would be anything similar to @alsetalokin's characteristic frequencies. Too bad the rotor isn't with me (will be back from the machine shop on Tuesday, I hope) so that I can record it at 425rpm to see if the fingerprints will be the same as in the original.

Also, Bruce has a resonance portion in his wave. Would be interesting to see if it coincides with mine and how it differs from other sections without resonance (say around 425rpm as in the original).

Omni,

You are correct regarding how I sampled your last soundtrack.  I focused on the increasing "noise" that you heard around 230 rpm.  The figure that I attached shows the octave bars as well as "peak" indicators for the bars.  The peaks indicate where the noise was loudest.

If you'd be so kind to post your "400 RPM" wave files for me, I'd be delighted to analyze them like the others.  I live in California, which is GMT-8.

Cheers, 

Yada..
.

[Omnibus]

@Yadaraf,

I posted them here: http://www.overunity.com/index.php/topic,3871.msg75008.html#msg75008.

Unfortunately, the stators themselves (not the N42's on top of them) are somewhat secured to avoid the wiggle when not held by hand. When I get my rotor back from the machine shop on Tuesday (hopefully) I'll record proper waves with stators turning as required.

[blue_energy]

OK good people...

I've just run a couple of Waves processors on the important part of the original video - generally to remove most of the multiband buzz and lift the detail a little. It's only a hi-res MP3 to limit file size from the processed WAV.

Maybe someone has got a little more time that myself to play around with it further, though hopefully will help to serve as a point of general reference. Must get some shut-eye now - work tomorrow and it's 2:25am over here !

http://www.funkyjive.com/Audio/  -  There's only one track - 9.4Mb


Chin chin 

FunkyJive

That was a heroic effort, FunkyJive!  I was hoping to use the resulting wav to do the same peak measuring thing I did with Bruce's.  But - it was scrambled too much.  It's too hard for me to tell where the peaks are - too hard to identify the sine within the complex wave.  Thanks for your effort anyway!

If anyone is interested, I took a stab at removing the noise from Als original video's audio as well.  I was fortunate in that there's over a half a second right at the beginning that's pure noise.  So - all of the humming noise is gone from my output now (good ol' Cool Edit Pro '96).  But, like FJ's - what's left has a slightly 'flanged' sound.  Also, even with that - I can't identify any rhythmic signature that I could use to judge when the rotor sped up.  The resulting file is over 4MB - so I can't post it here.  But, if someone can think of a use for it and wants it bad enough to arrange somewhere for me to ftp it to - I'd do that.

I've looked closely at sound files from three different Whipmag rigs now.  I'm really surprised at how smooth Al's is by comparison to the other two.  Is it his rotor bearings?  There's no 'beating' or clatter in the entire soundtrack.  It definitely goes up in pitch though, by the way.

[PolyMatrix]

Just been looking at @Al's wave file focusing on the moment of latching.ie just before Al says "there it goes". I amplified the wave and heard what I can only describe as a squeak at the moment of latching. I have not been through the whole sound track carefully but after amplifying the whole file the only point I hear this squeak is at the moment of latching.

Speculation: The rotor or the stator axial  is pushed hard against the bearing that for a moment metal rubs against metal.

[Yadaraf]

@Yadaraf,

I posted them here: http://www.overunity.com/index.php/topic,3871.msg75008.html#msg75008.

Unfortunately, the stators themselves (not the N42's on top of them) are somewhat secured to avoid the wiggle when not held by hand. When I get my rotor back from the machine shop on Tuesday (hopefully) I'll record proper waves with stators turning as required.

Omni,

See attached figures.  Looks like you have something happening around 80 Hz and 300 Hz

Edit:  Analyses were performed on data sampled within the first few seconds of the audio recordings.


Cheers, 

Yada..
.