Convert amplitude change to waveform: HOW? -Sound Forge - PC

Subject:Convert amplitude change to waveform: HOW? Posted by: Doug_Marshall Date:9/13/2006 6:33:45 PM How can I extract the data I need?... I have a wave file of an organ pipe which is being modulated by the pipe organ's tremolo (affecting amplitude and frequency). The amplitude changes clearly represent the effect of the tremolo on the pipe. I need to convert that amplitude data into a waveform that represents the the tremolo itself rather than the sound of the pipe. I'm certain this can be done, but how? I did a forum search and found some discussion of a plugin from Blue Cat Audio (Digital Peak Meter Pro) which looks like it might do this but I can't get the plugin to appear in Vegas or Sound Forge on my system. Any other tools out there? Thanks for all help! Doug Message last edited on9/14/2006 1:14:09 PM byDoug_Marshall.
Subject:RE: Convert amplitude change to waveform: HOW? Reply by: Geoff_Wood Date:9/14/2006 5:08:29 PM Track EQ. Set a shelving LPF to minimum freq (20Hz). The actual tremelo component of the signal will likely be less than 10Hz. But why ? geoff
Subject:RE: Convert amplitude change to waveform: HOW? Reply by: Doug_Marshall Date:9/14/2006 6:49:33 PM Thanks. I've been working with the filters and even with multiple passes, the original note's pitch (in this case, around 500 Hz) is reduced but not removed. The trem component is about 6 Hz in this case. But why? Good question. To drive a software simulator. I could create a waveform and use it but real trems are so much more interestingly random!
Subject:RE: Convert amplitude change to waveform: HOW Reply by: jackn2mpu Date:9/30/2006 12:35:49 PM You might want to try some sort of envelope follower (it'll follow the amplitude changes in the waveform). Unfortunately, the only ones I know about are hardware, not software. A second thought just occurred: might an impulse response program work in this case? Treat the wavefrom that you've recorded as if you were making your own IR's for use in a convolution processor. Jack

Subject:Convert amplitude change to waveform: HOW?

Date:9/13/2006 6:33:45 PM

How can I extract the data I need?...

I have a wave file of an organ pipe which is being modulated by the pipe organ's tremolo (affecting amplitude and frequency). The amplitude changes clearly represent the effect of the tremolo on the pipe. I need to convert that amplitude data into a waveform that represents the the tremolo itself rather than the sound of the pipe. I'm certain this can be done, but how?

I did a forum search and found some discussion of a plugin from Blue Cat Audio (Digital Peak Meter Pro) which looks like it might do this but I can't get the plugin to appear in Vegas or Sound Forge on my system. Any other tools out there?

Thanks for all help!
Doug

Message last edited on9/14/2006 1:14:09 PM byDoug_Marshall.

Subject:RE: Convert amplitude change to waveform: HOW?

Reply by: Geoff_Wood

Date:9/14/2006 5:08:29 PM

Track EQ. Set a shelving LPF to minimum freq (20Hz). The actual tremelo component of the signal will likely be less than 10Hz.

But why ?

geoff

Subject:RE: Convert amplitude change to waveform: HOW?

Reply by: Doug_Marshall

Date:9/14/2006 6:49:33 PM

Thanks. I've been working with the filters and even with multiple passes, the original note's pitch (in this case, around 500 Hz) is reduced but not removed. The trem component is about 6 Hz in this case.

But why? Good question. To drive a software simulator. I could create a waveform and use it but real trems are so much more interestingly random!

Subject:RE: Convert amplitude change to waveform: HOW

Reply by: jackn2mpu

Date:9/30/2006 12:35:49 PM

You might want to try some sort of envelope follower (it'll follow the amplitude changes in the waveform). Unfortunately, the only ones I know about are hardware, not software.

A second thought just occurred: might an impulse response program work in this case? Treat the wavefrom that you've recorded as if you were making your own IR's for use in a convolution processor.

Jack