LAFCPUG: Audio FAQs

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Use Effects - Audio Filters - Apple - AUDynamicsProcessor. The Gain option will allow you to add up to 40dB of boost on top of the 12dB provided within the clip. If 52dB of gain can't make your audio high enough, then your original audio is almost certainly unusable.
Use Effects - Audio Filters - Apple - AUDynamicsProcessor. The Gain option will allow you to add up to 40dB of boost on top of the 12dB provided within the clip. If 52dB of gain can't make your audio high enough, then your original audio is almost certainly unusable.
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'''From Strypes'''
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In FCP 6, a Gain option has been added. It's in Effects - Audio Filters - Final Cut Pro - Gain.

Revision as of 18:57, 26 October 2008

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Audio FAQs


Contents

How do I capture four (or more) tracks of audio at once?

From Michael Horton

Assuming you are capturing via Firewire,

  • Go to Audio Video Settings> Capture Presets
  • Click Edit

From the QuickTime Audio Settings > Input, you can choose to :

  • Capture the first two channels
  • Capture the second two channels
  • Capture mix of four channels

Mixed you can do in one pass and you still wind up with two audio tracks mixed down.

Two pass you will have all four channels on separate tracks, but you would capture the first two normally, then change it to the second two channels.


Another way from Martin Baker:

Up to 24 channel audio capture is supported as of FCP 5. Most capture cards support up to 8 channels of embedded audio through SDI (though Kona 3 offers up to 16 channels of embedded). I'm not aware of any capture cards which offer more than 8 AES or analogue inputs.


So depending on how many channels you want to capture, the other possibility is to use a separate audio interface such as MOTU or RME. If the interface has Core Audio drivers available then it should appear as a device in FCP's Capture Preset Editor. There may be A/V sync issues with this method although if you can genlock the audio interface then I would imagine it would work fine.


I doubt there is anyone who has ever tried this but in theory it would work.



I hear popping & clicking sounds

From Jude Cotter

You will hear these sounds if there is a mismatch between the clip audio format and the sequence audio format. Most commonly this happens when attempting to use MP3s. The best thing to do is to convert the files to 48khz AIFFs, and import these to work with in FCP. You can do this either in iTunes or QuickTime.


  • In iTunes go to iTunes > Preferences > Advanced > and select the ‘Importing’ tab.
  • Then set ‘Import Using’ to ‘AIFF Encoder’, ‘Setting’ to ‘Custom’, ‘Sample Rate’ to 48.000kHz, ‘Sample Size’ to ‘16 bit’ and ‘Channels’ to ‘Stereo’.
  • Find your tracks in the iTunes Library and select ‘Convert’ from the ‘Advanced’ menu.

This option is best if you need to batch convert a lot of songs.

or

  • In QuickTime, open the file and choose File > Export.
  • Change the ‘Export’ setting at the bottom of the window to ‘Sound to AIFF’.
  • Click on ‘Options’ and check that the settings are correct. Then save to the location of your choice.


Other things that could help:

  • Before you output your sequence to a movie file or to tape, you must perform an Audio Mixdown. This does not mix all your audio tracks to two tracks; it merely serves as an audio render for the entire timeline - it creates a single preview file that is less stressful for the computer to play. You can find this in FCP under Render > Only > Mixdown.



Imported songs from a CD

From Jude Cotter

If you imported some songs from a CD and it worked at first, but now the files are missing and won't play, it's probably because FCP (on OSX) does not automatically create a file on your hard drive during import. Instead, it makes a "dependent" or "reference" clip to the CD.


This means that once you eject the CD, FCP no longer has access to the audio file. To ensure that you always have access to the file for use in FCP, you must convert any CD tracks to AIFFs and store them in your computer before importing them into FCP.


To do this:

  • In iTunes go to iTunes > Preferences > Advanced > select the ‘Importing’ tab.
  • Then set ‘Import Using’ to ‘AIFF Encoder’, ‘Setting’ to ‘Custom’, ‘Sample Rate’ to 48.000kHz, ‘Sample Size’ to ‘16 bit’ and ‘Channels’ to ‘Stereo’.
  • Find your tracks on the CD and select ‘Convert’ from the ‘Advanced’ menu.

or

  • In QuickTime, open the file and choose File > Export.
  • Change the ‘Export’ setting at the bottom of the window to ‘Sound to AIFF’.
  • Click on ‘Options’ and check that the settings are correct. Then save to the location of your choice.


Then import the files you have created into FCP.


Other things that it could be:

  • If you did all this before importing the files and they‘ve still gone missing, it could be that the name of the files has been changed on the hard drive, so that FCP no longer recognises them as the correct files. Either change the names of the files back to what they were, or reconnect them in FCP by deselecting ‘Matched name only’ in the reconnect dialogue box.



Why do I hear beeping?

From Jude Cotter

The beeping noise is the audio render alert. It means that you need to render your audio. A normal render should do this, as long as you have ‘Audio’ checked under Sequence > ‘Render Selection’ and/or ‘Render All’.


Also, from Nick Meyers
Increase your Real Time Audio Mixing track allocation in User Preferences to perhaps 16 tracks rather than the default 8.



Some sections of my audio are missing or sputtering

From Jude Cotter
Probably, your computer has reached the limit of what it is able to display in real time. You may find that your video also starts to splutter after a while. What you need to do is to reduce the pressure on the system by doing an 'Audio Mixdown'. This creates a single stereo preview file for FCP to play when you watch your timeline. This is not the same as an audio render.


Doing this does not actually mix all your audio together - all your audio is still separated exactly as you have designed it to be - there is just a single extra file that represents what audio decisions you have made. If you change anything in the audio, you will need to do the Audio mixdown again. Fortunately, this is quite quick.


To do an audio mixdown, go to Render > Only > Audio Mixdown.


If the Audio mixdown starts to become too tedious, you need to reduce the pressure on your system further (or get more RAM, a bigger computer etc). Try exporting sections of your work that are locked-off to self contained Quicktime movies and re-importing them to use in place of the more complicated parts of your timeline.


Other things that it could be:

  • Your audio is actually missing. Check your original files and tapes.
  • You have accidentally turned off or deleted a part of your audio. Check that everything appears normal on the timeline.


Also


From Loren Miller

Sometimes when you play back a properly captured and edited DV 48K timeline or Print to Video via Firewire, while utilizing FireWire drives going to a FireWire deck, you can encounter an unrepairable audio dropout - usually at a consistent point in the timeline - even though you can see waveforms, and audio signal registers on the meters!!


In these cases, you may be encountering a FireWire "perfect storm"-- a brief and utterly annoying conflict between DV from your drives and DV signal from/to the deck. I've experienced it on a Dual 800 G4 with 1.5 GB RAM, OSX 10.4.8, FCP 5.1.2, QuickTime 7.1.5 with a Sony DSR-40 attached. Your milage may vary with newer machines and so far as I know, it's only a DV issue.


If you're really experiencing the Perfect Storm, nothing you attempt to fix it will work. Moving a long master clip to another drive won't help. Moving your drive plugs and deck plug around won't help. Re-capturing the "trouble spot(s)" won't help-- the data remains the same-- it conflicts somehow in the sequence or pipeline. Trashing your prefs, POA caches and other settings won't help. This is a systemic disorder. So save time!


From Apple's Final Cut Pro 6 User Manual -

"Certain DV camcorders cannot be connected to a computer while a FireWire disk drive is connected simultaneously. In many cases, you can improve performance by installing a separate FireWire PCI card to connect your FireWire drive."


As indicated, this doesn't always work either. If you're playing out to a FireWire deck (such as a Sony DSR-20, 25, 40 or 45, etc) turn off the deck connection (Command F12- Toggle External Video), and try to play the timeline strictly on your computer speakers and screen.


If you confirm the audio is actually there, and playing normally, export the sequence (either reference or self-contained Final Cut Pro movie-- both work) and play it to your deck via Apple's SimpleVideoOut utility. It's a lean and mean play-out app used to demonstrate QuickTime playback using several protocols, including FireWire. In my non-engineering opinion, something in SVO works where something in Final Cut Pro's FireWire pipeline is munging data!


It may save your day. Then think about moving your media drives to eSata.



I'm having sync problems

From Jude Cotter

If you're playing back to an external monitor, you must also listen to the sound with an external playback device. If you're watching the image on the Viewer or Canvas, then you must listen to the sound on the computer's Built-In Audio option under Audio/Video Settings, or by turning View - External Video off (at which point Built-In Audio will kick in). If you're watching external video, for example FireWire from the computer to a deck to a monitor/TV, then you must monitor sound from the deck or the monitor/TV.


Other things that it could be:
Have you accidentally slipped the sync in the timeline? Check the original clip against the version on the timeline. You may see a small set of red numbers on the out of sync clips. This number is a guide to how far off sync you have moved. To fix this, right click or control-click an out-of-sync indicator to reveal a shortcut menu with several options.


‘Move into Sync’ moves the selected track so that its In point syncs with that of the associated track. Make sure you have enough room on the timeline for the track to move into. You can also just select the out of sync clip and type the number indicated in the red boxes. Make sure to add a minus if you need the clip to move backwards.


More help/solutions can be found here : Dropped Frames: Causes and Solutions



No audio from movie file (MPEG) after I import

From Jude Cotter
MPEG-1 and some other compressed codecs use ‘muxed’ or ‘multiplexed’ audio, which means that the audio is mixed in with the video. FCP does not like this.


To check for muxing, open the clip in QuickTime Player and press APPLE-J. Check the Sound Track. If you see the words "Muxed Track", the clip needs to be 'demuxed' before it can be used for editing. You can do this with MPEGStreamclip


Other things that it could be

  • If you have external speakers, check that these are turned on and set up correctly. Make sure your mixer, if any, is on and that everything is securely connected.
  • Try restarting FCP.
  • If all else fails, try trashing your preferences to restore the factory settings. Instructions on how to do this can be found here : How to trash your preferences, or you can use Preference Manager , FCP Attic or FCP Rescue, all of which will restore user-defined settings.



How can I get rid of background noise?

From Jim Perry

The best way is to not record it in the first place! Get the mic close by using a lavaliere or a shotgun mounted on a boom-pole positioned right above the talent by an alert boom operator. Turn off the heat or AC and use sound-deadening materials to block noise and sound reflection.


If it's too late for that, try these techniques (using good speakers or headphones):

  • Use the graphic equalizer audio filter in FCP to attenuate frequencies outside the voice range (below 100hz and above around 5000hz).
  • Use the Expander/Noise Gate audio filter in FCP to reduce the volume of the quiet sections of your audio. This makes the presence of noise less noticeable, although if overdone it can sound like the noise is pumping up and down.
  • Use a commercial noise reduction product like Bias SoundSoap These products apply a sophisticated analysis of the noise, then reduce it by using the above techniques along with more esoteric approaches such as frequency cancellation.
  • Add in some bed-level music, or even some room ambience sound, to mask the noise.


Audio post-production is an art and science unto itself, so don't expect to win an Oscar with the audio tools available within FCP. For further information, see: SoundSoap, Soundtrack Pro and Optimizing Audio in FCP 4


For those thinking of going down the Soundtrack Pro path here's Wayne Grazin's Soundtrack Pro noise reduction workflow :


Noise minimizing in Soundtrack is a breeze.

  • Open your movie with Soundtrack Pro.
  • Locate and highlight a section of the clip that ONLY has the noise.
  • Under PROCESS, pull down to SET NOISE PRINT.
  • FILE > SELECT ALL (not sure if this is required, but i find it easier to judge the results)
  • Hit the spacebar to play the sound.
  • Under PROCESS, pull down to REDUCE NOISE... and play with the values until you like what you hear. i generally find it sufficient to just adjust the top "noise threshold" slider.
  • Hit APPLY when you like what you hear.


Keep in mind that although this is an exceptionally good noice reducer for the money - and it can work miracles with moderately bad audio, there is only so much it can do without negatively effecting the desired sound as well.



Boosting audio levels

From Jude Cotter

At the bottom left of your timeline there is a small button that looks like a mountain range. This is the 'Toggle Clip Overlays' button. Click this to turn it on. You should now see a pink line running through the middle of all of your audio tracks on the timeline. With your arrow tool selected, you can grab this line and shift it up and down to adjust your sound levels.


You can also see and adjust your levels in the Viewer by double clicking your audio clip to load it into the viewer. Here you can make adjustments either in the same way as you did on the timeline, or numerically. There are also menu options and keyboard shortcuts for adjusting the levels. Look under Modify > Levels and Modify > Audio.


On top of all this, there is an Audio Mixer in FCP that you can access via Tools > Audio Mixer, or by selecting Window > Arrange > Audio Mixing.


If, after you have raised these levels to their limits, the sound is still too low, there are a couple of things you can do.


One simple method is to duplicate the clip and double it up on another audio line, so that you have two, or four or more lines of the exact same clip running at the same time. To do this, select the clip you need, hold option and shift, and drag the clip up or down into an empty space on your timeline. Holding option causes the clip to become duplicated, and holding shift keeps the audio in line (and therefore in sync) with the clip it has been duplicated from. This is endlessly repeatable, so you could, given nesting, have an infinite number of duplicates of your audio clip.


For users who are more proficient with sound and want more scope to manipulate their audio, you may want to explore SoundTrack Pro, which comes with FCP Studio.


Also:

From Derek Mok

Use Effects - Audio Filters - Apple - AUDynamicsProcessor. The Gain option will allow you to add up to 40dB of boost on top of the 12dB provided within the clip. If 52dB of gain can't make your audio high enough, then your original audio is almost certainly unusable.


From Strypes

In FCP 6, a Gain option has been added. It's in Effects - Audio Filters - Final Cut Pro - Gain.



Where can I find music to use in my projects?

From Jude Cotter

Here is a starter list of music that you can access on the internet. It is not necessarily an endorsement of the companies listed.



In most cases the costs depend on what your project is and where is will be seen. For more information about performance rights in your country, check here : Performance Rights Worldwide

For more music download options, google 'production music' or 'buyout music'.



Understanding Voice Processing

From Strypes

We usually hear sounds as a complex sonic envelope, which largely consists of fundamental frequencies, a series of harmonics, and additional reflected sounds. Depending on the acoustics of the room, some frequencies are more easily absorbed or lost into the environment, the further we are from the source. Sound perspective of a voice in a large room heard from a distance, could include a reduction of high frequencies, a higher amount of reverb, and a softer mix of the person's direct sound.


To equalize a voice, it is important to understand what frequency ranges constitute the different components of a voice. Fundamental frequencies of a voices starts at around 85Hz for bassy male voices and an octave higher (around 200Hz) for women. Speaking ranges are generally between 150-500Hz, nasal frequencies around 2kHz, presence around 5kHz, sibilence 8kHz to 12kHz. Crispness is added above 16kHz. Equalizer treatments differ on a case by case basis, as it relies heavily on what the source material is, how the voice was captured, etc.


A general EQ treatment of a close mic-ed interview (lapel mics strapped on a chest) would include cutting the low frequencies- a low shelving EQ below 100Hz, a low EQ cut centered around 200Hz to 300Hz to remove proximity effect. As well as a slight boost at the nasal range centered around 2kHz to improve clarity. And if situations allow, a boost around 5-6khz to help reshape the sound slightly.


For location recordings, occasionally line rate hums from on location broadcast monitors may be captured. The high pitched sound from the monitors are caused by line rates which can be eliminated by a sharp parametric EQ cut at 15.734kHz for NTSC (525 lines x 29.97fps) and 15.625kHz for PAL (625 lines x 25fps).


Additional audio treatment on vocals also include Compressors to limit the dynamic range of the voice; Multiband Compressors and Limiters which are usually used in mastering; Reverb for sonic perspective; Noise Gates, Expanders and De-Noisers to reduce noise.


For more information, SoundOnSound has great resources to read up on.



Pans in Final Cut Pro

From Strypes

A unique nonmenclature adopted by Apple. On Stereo linked clips, "-1" refers to a full stereo spread on stereo linked tracks with the first track panned extreme left and the second track panned extreme right; "0" refers to both tracks being centred (also known as a "Mono" setting); "1" inverses the stereo fields, with the first track panned extreme right and the second track panned extreme left.

On Mono clips, "-1" pans the clip onto the left speaker, "0" centers the clip on the stereo spectrum, "1" pans the clip onto the right speaker.



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