Week-6 Wrap-up:
There are some hopes that work may start again. I expect it will be a slow start-up. And I don't foresee things returning to normal for a long time. The virus is not going anywhere. Until there is a vaccine or treatment, we will need to live with restrictions and precautions to limit the spread of the virus.
The Covid-19 layoff has given me time for one of my favorite hobbies; audio engineering. Something I learned and loved in college. Along with photography, I had interest in audio production.
I started digital audio editing with Cool Edit Pro software in the late 1990s. When Adobe bought them, I switched to their Audition software. I repair defects and improving the sound with old music.
It may seem odd that a gaffer is working with audio, but it is like working with light. It is similar to editing pictures with Photoshop. Audition is Photoshop for the ears.
Here are a couple recent projects:
This is a live jazz recording from around 1960 that a friend sent me to repair.
This is a spectral view of about 12 seconds of music showing amplitude at different frequencies: black is no sound; the brighter the color, the greater the amplitude; bass is at the bottom with the pitch getting higher as you look up the graph; and there are 2-channels, left and right.
The most obvious problem are the 2 black bands in the music. These are severe dropouts likely from some damage to the audio tape. It could be a bad crease or even break in the tape that was badly spliced.
The other major problem here are the bright bands around the dropouts. These are loud pops in the music. This is also some kind of tape damage, maybe a bad crease in the tape.
Here is the same music repaired.
The defects are “magically” gone. Listening to the music, you cannot tell that there was ever any problem.
It is a lot of work repairing problems like this. The dropouts were carefully soft-spliced out. Some of the pops were also soft-spliced out. Some of the smaller pops were individually removed using the Audition spot healing brush tool.
After repairs, I removed the tape hiss, ran some filters, like a graphic equalizer, and widen the stereo image a bit.
The finished music sounds great.
Here is another much different project:
This clip is from a great Telarc recording of An American In Paris with the Cincinnati Orchestra from 1981. Telarc was one of the first companies embracing digital recordings. They were fanatics about making recording that captured the true sound of the music without using any processing. Their recordings are classics. The source audio is an old CD.
Looking to the left side of the clip, you can see many dark bands running through the music. This is good. It shows a very clean recording without background noise, and unlike most recordings from back then and earlier, no tape hiss. The tape hiss shows up like a fog.
You wouldn’t expect a Telarc recording to need any audio repairs, but surprisingly it has an issue.
Looking on the right side you can see noise in the sub-bass region after the music has ended. It runs under the music, too.
The good news is software can remove defects like this without effecting the music or creating artifacts. The key to a good removal is getting a good sample of the noise. There is 5 seconds of noise here, so I was able to get a great sample. For example, I am often working with clips that are less than a second.
Here is the same clip with the noise removed.
You can see the noise is gone. I could only dream of doing something like this when I was in college. The technology is amazing.
For the finished music, I filtered in more treble and widen the stereo slightly. It gave the sound more vibrance, where before it seemed somewhat flat.
The finished music is extraordinary. It sounds like the orchestra is in my house.
This is a fun hobby for me. It is relaxing, keeps my mind busy, and is rewarding when the music turns out well.
There are some hopes that work may start again. I expect it will be a slow start-up. And I don't foresee things returning to normal for a long time. The virus is not going anywhere. Until there is a vaccine or treatment, we will need to live with restrictions and precautions to limit the spread of the virus.
The Covid-19 layoff has given me time for one of my favorite hobbies; audio engineering. Something I learned and loved in college. Along with photography, I had interest in audio production.
I started digital audio editing with Cool Edit Pro software in the late 1990s. When Adobe bought them, I switched to their Audition software. I repair defects and improving the sound with old music.
It may seem odd that a gaffer is working with audio, but it is like working with light. It is similar to editing pictures with Photoshop. Audition is Photoshop for the ears.
Here are a couple recent projects:
This is a live jazz recording from around 1960 that a friend sent me to repair.
This is a spectral view of about 12 seconds of music showing amplitude at different frequencies: black is no sound; the brighter the color, the greater the amplitude; bass is at the bottom with the pitch getting higher as you look up the graph; and there are 2-channels, left and right.
The most obvious problem are the 2 black bands in the music. These are severe dropouts likely from some damage to the audio tape. It could be a bad crease or even break in the tape that was badly spliced.
The other major problem here are the bright bands around the dropouts. These are loud pops in the music. This is also some kind of tape damage, maybe a bad crease in the tape.
Here is the same music repaired.
The defects are “magically” gone. Listening to the music, you cannot tell that there was ever any problem.
It is a lot of work repairing problems like this. The dropouts were carefully soft-spliced out. Some of the pops were also soft-spliced out. Some of the smaller pops were individually removed using the Audition spot healing brush tool.
After repairs, I removed the tape hiss, ran some filters, like a graphic equalizer, and widen the stereo image a bit.
The finished music sounds great.
Here is another much different project:
This clip is from a great Telarc recording of An American In Paris with the Cincinnati Orchestra from 1981. Telarc was one of the first companies embracing digital recordings. They were fanatics about making recording that captured the true sound of the music without using any processing. Their recordings are classics. The source audio is an old CD.
Looking to the left side of the clip, you can see many dark bands running through the music. This is good. It shows a very clean recording without background noise, and unlike most recordings from back then and earlier, no tape hiss. The tape hiss shows up like a fog.
You wouldn’t expect a Telarc recording to need any audio repairs, but surprisingly it has an issue.
Looking on the right side you can see noise in the sub-bass region after the music has ended. It runs under the music, too.
It’s a low frequency rumble. You would never hear it unless you have a sub-woofer with your stereo. I can’t imagine that it was part of the original recording. My guess it is an artifact introduced at some point with the mastering process. This is a defect I have never seen before. I don't think it is the sound of the hall. The engineers seemed to have faded-out the sound when the music stopped playing, but the noise continues.
I wonder if it is some early form of dithering. Dithering is a noise added cover noise/artifacts created when down-sampling the bit-rate of an audio file.
Dithering sounds like it would be a bad thing adding noise, but it is a good thing. You don't hear the dithering and the music sounds better.
The good news is software can remove defects like this without effecting the music or creating artifacts. The key to a good removal is getting a good sample of the noise. There is 5 seconds of noise here, so I was able to get a great sample. For example, I am often working with clips that are less than a second.
Here is the same clip with the noise removed.
You can see the noise is gone. I could only dream of doing something like this when I was in college. The technology is amazing.
For the finished music, I filtered in more treble and widen the stereo slightly. It gave the sound more vibrance, where before it seemed somewhat flat.
The finished music is extraordinary. It sounds like the orchestra is in my house.
This is a fun hobby for me. It is relaxing, keeps my mind busy, and is rewarding when the music turns out well.
PS: I'm
often removing tape hiss noise from recordings, but is often difficult
to get a clean sample. It is becasue engineers try to "hide" the hiss by fading in-and-out with the music. This way there is no silence where the tape hiss would become obvious.
I had an insight years ago that tape hiss is a
uniform noise across all frequencies. I found that I only need a short
partial sample. For example, I could get a tape hiss sample of only above 10k Hz while there is still music like bass below 300 Hz.
I can
then shift the sample to different frequencies, until I have samples that covers all frequencies. I filter the overlaps, and
mix the samples down to create a full frequency sample. I then use this
generated sample to remove the tape hiss. This method is very
effective.