Acoustic Impulses - one more time -Sound Forge - PC

Subject:Acoustic Impulses - one more time Posted by: Hummingbird Date:2/20/2003 7:41:58 AM I located a group of acoustic impulses at: http://orpheus.tamu.edu/fredrics/isrc.html Fredrics apparently burst a balloon in the spaces he recorded, so the resulting file includes the balloon explosion followed by the reverberation. He saved these impulses in AIFF format which I have been able to open and listen to in Sound Forge. In reading Sound Forge's help file for recovering the impulse, instructions require that I delete all audio before the "first timing spike" and from the start of the "second timing spike" to the end of the file. I'm confused as to what the term "timing spike" means. It appears that the balloon explosion itself lingers over several peaks and valleys of the waveform. Are these peaks the "spikes" referred to? If so, won't the initial explosion be all that remains after I delete all the reverberation? I would sure appreciate some help. I'm a little dense about some of the terminology I occasionally encounter. Hummingbird
Subject:RE: Acoustic Impulses - one more time Reply by: musicvid10 Date:2/21/2003 12:21:40 AM I checked the site, and I don't know that those recordings could be made useful for generating Acoustic Mirror impulses. Acoustic Mirror uses a reference sound file compared to an acoustic recording of the file to generate the impulse. The spikes referred to are registration points at the beginning and end of the file, much like a movie clapboard. Without a corresponding dry reference file, I don't know how these could be used in Acoustic Mirror.
Subject:RE: Acoustic Impulses - one more time Reply by: rjt Date:2/22/2003 2:50:21 PM I may be missing something.... I converted the AIFF files to WAV using the SF Batch converted. I then used the batch converted to delete silence from the beginning and the end of the files. They seem to sound okay when used in AM. Some are better than others. Many of the wooden churches, for example, seem fine. Some, like the large stone cathedrals, seems to have an interminable reverb which sounds kind of noisey. I use the high filter cut off and envelope follower to tailor those reverbs a bit. Anyway, try the raw Bethany 2 file. Seems to work fine. Take care

Subject:Acoustic Impulses - one more time

Posted by: Hummingbird

Date:2/20/2003 7:41:58 AM

I located a group of acoustic impulses at:

http://orpheus.tamu.edu/fredrics/isrc.html

Fredrics apparently burst a balloon in the spaces he recorded, so the resulting file includes
the balloon explosion followed by the reverberation. He saved these impulses in AIFF
format which I have been able to open and listen to in Sound Forge.

In reading Sound Forge's help file for recovering the impulse, instructions require that I
delete all audio before the "first timing spike" and from the start of the "second timing
spike" to the end of the file. I'm confused as to what the term "timing spike" means. It
appears that the balloon explosion itself lingers over several peaks and valleys of the
waveform. Are these peaks the "spikes" referred to? If so, won't the initial explosion be
all that remains after I delete all the reverberation?

I would sure appreciate some help. I'm a little dense about
some of the terminology I occasionally encounter.

Hummingbird

Subject:RE: Acoustic Impulses - one more time

Reply by: musicvid10

Date:2/21/2003 12:21:40 AM

I checked the site, and I don't know that those recordings could be made useful for generating Acoustic Mirror impulses. Acoustic Mirror uses a reference sound file compared to an acoustic recording of the file to generate the impulse. The spikes referred to are registration points at the beginning and end of the file, much like a movie clapboard. Without a corresponding dry reference file, I don't know how these could be used in Acoustic Mirror.

Subject:RE: Acoustic Impulses - one more time

Reply by: rjt

Date:2/22/2003 2:50:21 PM

I may be missing something.... I converted the AIFF files to WAV using the SF Batch converted. I then used the batch converted to delete silence from the beginning and the end of the files. They seem to sound okay when used in AM. Some are better than others. Many of the wooden churches, for example, seem fine. Some, like the large stone cathedrals, seems to have an interminable reverb which sounds kind of noisey. I use the high filter cut off and envelope follower to tailor those reverbs a bit. Anyway, try the raw Bethany 2 file. Seems to work fine.

Take care