I'm not going to cover proper sound capture techniques on set other than to mention the traditional bits. To wit: Microphone as close to subject as the shot will allow, you are capturing only the voice of the actor, not everything around them, wear headphones while recording and listen to what you're getting, watch your levels, keep them from peaking as digital will simply lose the sound that "clips". Capture any environmental sounds that you feel you need separately in 30+ second sound bites and sound fx from before the sound until after it's faded.
This particular tutorial deals with the bits that are ignored in sound; Post Production and Sweetening.
Understanding and Visualizing Sound:
Sound is made up of a range of differently pitched sounds (called frequencies) that work together to create the sounds we hear. Whether that be a train whistle, a waterfall, thunder or a person's voice, they are all comprised of waves of sound at different frequencies hitting the ear drum.
The human voice occupies a narrow band of these frequencies. Cutting out the frequencies not used in the vocal track will help to isolate your actor's voices and give you more control in post over the audio in your project.
To see your sound, use a spectrum graph rather than the waveform view of your soundtrack. The waveform so common only shows time vs. loudness (amplitude), whereas the spectrum graph shows time vs. frequency with amplitude shown as color within the graph. This 3-dimensional graph will allow you to see where the sounds in your recording occur. Most graphs show a linear scale for frequency, wee prefer to look at it as a logarithmic scale (in Soundtrack Pro, the waveform/spectrum buttons are in the upper right hand portion of the main window and switching to log is as simple as right clicking in the frequency scale and selecting logarithmic).
High Cut, Low Cut:
To eliminate as much background noise as possible from an audio track, apply a low cut at adjust it higher until it just starts to make your vocals sound hollow. Then apply a high cut and lower it until the same happens at the other end of the voices.
EQ Tricks, Notch Filter:
On set, we try to eliminate all sounds other than our actor's voices. We do this by using very sensitive microhones with a huge ability to reject off-axis noise. We try to get home and business owners to allow us to turn off any noise makers on set, refrigerators, ceiling fans, humidifiers, A/C...
These don't always work, either something gets missed or the owners won't allow refrigeration/ cooling to be turned off (like in an open and operating restaurant). In these cases, making sure the microphone is pointed in a way that minimizes these noises can be utilized (front and rear of the microphone perpendicular to the offending noise source and not toward surfaces that would reflect those sounds.
To find these frequencies, look at the spectral graph, horizontal lines relate to sound with a consistent frequency (like a humming refrigerator). To eliminate this humming, add a notch filter to the track. There are 3 controls: Frequency, Q and Amplitude. The frequency should match the sound you're going to remove, the Q adjusts the amount of frequencies around the target that are affected and the Amplitude is the volume adjustment.
Start by setting the Q as high as it goes, do the same to the amplitude. While previewing the sound (looping around the bit you want to fix), scrub the frequency until the sound becomes painfully really loud. Once you've identified the frequency this way, drop the amplitude as low as it goes and the sound should magically disappear. You may need to adjust the Q wider to cover the adjoining frequencies to fully remove the sound.
Lather, rinse repeat keeping in mind that we prefer not to negatively impact the subject of the recording. If two sounds are in the recording at the same frequency, the loudest sound will drown out the same frequency in other sounds in the recording. So if you do have to poke a hole in the subject of the recording, make sure to find ambiance, sound fx or music at those frequency ranges to plug the holes you create now.
This should get you started presenting cleaner sound in your productions without too much hassle. The frequency scrubbing technique will work evern without the spectral graph and allow you to do all of this sound work within your NLE if necessary (although it'll take more time to render, so account for that)... but if you're taking the time to learn all kinds of Special FX tricks, you may as well learn these tricks as well. It's all just operating on digital information anyway, and all of the time you take in post will make your results more and more professional.
This installation deals with removing sound. Later, we'll cover adding sounds to make your overall soundtrack richer and more professional sounding.
This particular tutorial deals with the bits that are ignored in sound; Post Production and Sweetening.
Understanding and Visualizing Sound:
Sound is made up of a range of differently pitched sounds (called frequencies) that work together to create the sounds we hear. Whether that be a train whistle, a waterfall, thunder or a person's voice, they are all comprised of waves of sound at different frequencies hitting the ear drum.
The human voice occupies a narrow band of these frequencies. Cutting out the frequencies not used in the vocal track will help to isolate your actor's voices and give you more control in post over the audio in your project.
To see your sound, use a spectrum graph rather than the waveform view of your soundtrack. The waveform so common only shows time vs. loudness (amplitude), whereas the spectrum graph shows time vs. frequency with amplitude shown as color within the graph. This 3-dimensional graph will allow you to see where the sounds in your recording occur. Most graphs show a linear scale for frequency, wee prefer to look at it as a logarithmic scale (in Soundtrack Pro, the waveform/spectrum buttons are in the upper right hand portion of the main window and switching to log is as simple as right clicking in the frequency scale and selecting logarithmic).
High Cut, Low Cut:
To eliminate as much background noise as possible from an audio track, apply a low cut at adjust it higher until it just starts to make your vocals sound hollow. Then apply a high cut and lower it until the same happens at the other end of the voices.
EQ Tricks, Notch Filter:
On set, we try to eliminate all sounds other than our actor's voices. We do this by using very sensitive microhones with a huge ability to reject off-axis noise. We try to get home and business owners to allow us to turn off any noise makers on set, refrigerators, ceiling fans, humidifiers, A/C...
These don't always work, either something gets missed or the owners won't allow refrigeration/ cooling to be turned off (like in an open and operating restaurant). In these cases, making sure the microphone is pointed in a way that minimizes these noises can be utilized (front and rear of the microphone perpendicular to the offending noise source and not toward surfaces that would reflect those sounds.
To find these frequencies, look at the spectral graph, horizontal lines relate to sound with a consistent frequency (like a humming refrigerator). To eliminate this humming, add a notch filter to the track. There are 3 controls: Frequency, Q and Amplitude. The frequency should match the sound you're going to remove, the Q adjusts the amount of frequencies around the target that are affected and the Amplitude is the volume adjustment.
Start by setting the Q as high as it goes, do the same to the amplitude. While previewing the sound (looping around the bit you want to fix), scrub the frequency until the sound becomes painfully really loud. Once you've identified the frequency this way, drop the amplitude as low as it goes and the sound should magically disappear. You may need to adjust the Q wider to cover the adjoining frequencies to fully remove the sound.
Lather, rinse repeat keeping in mind that we prefer not to negatively impact the subject of the recording. If two sounds are in the recording at the same frequency, the loudest sound will drown out the same frequency in other sounds in the recording. So if you do have to poke a hole in the subject of the recording, make sure to find ambiance, sound fx or music at those frequency ranges to plug the holes you create now.
This should get you started presenting cleaner sound in your productions without too much hassle. The frequency scrubbing technique will work evern without the spectral graph and allow you to do all of this sound work within your NLE if necessary (although it'll take more time to render, so account for that)... but if you're taking the time to learn all kinds of Special FX tricks, you may as well learn these tricks as well. It's all just operating on digital information anyway, and all of the time you take in post will make your results more and more professional.
This installation deals with removing sound. Later, we'll cover adding sounds to make your overall soundtrack richer and more professional sounding.