Good advice for the non-sound professional to make your video sound more professional.

Audio for video applications are amongst the most important tools of the total video project. Often, people are far more forgiving of bad video quality than bad audio quality. If you think about it, hearing clearly and distinctly what two characters are saying to each other gives you a much better feel of what's going on in the scene - even if the video quality is somewhat blurry or choppy. Bad audio is also distracting. For instance, you record two actors talking to one another both standing on a busy street corner. The audio is okay, but there's a lot of wind and other ambient uncontrollable noises. This is the time where you would most likely prefer to loop in the dialogue later. As it's inadvisable to use the sound treated room in this instance, you could simply re-record that dialogue in an outdoor setting with less intrusive ambient sound. Even consumer video quality can be compensated for through video processing techniques, to an extent. However, bad audio is very difficult to correct, and in most cases when fixing bad audio, you'll be left with the lesser of two evils.

 Do I eliminate "wind rumble" that's overlapping important dialogue? And in doing so, do I remove essential frequency elements in the actor's voice?

In all aspects of media there is one consistent truth, an aphorism if you will, that goes like this:

"garbage in - garbage out."

In other words, no matter how much fix up you do in your post production processes, the overall end result will be diminished quality, if the raw source of your audio is low quality and noisy to begin with.

When it comes to audio for video, the goal is to capture an actors' dialogue as clearly as possible while eliminating all other sources of noise other than what is coming out of their mouth. Ambient noise, room noise, or street noises can (and definitely should) be mixed in with the actors' dialogue later.

There are mild exceptions to the rule above. But only so much in the following contexts:

When dialogue from an actor is being recorded in a soundproof booth, but the actual scene takes place on a busy city street; the results will be strange. Voices carry very differently out in the open air. It's important, if you must "loop-in" or record the voices later to replace bad outdoor audio; that you do so under the same relative conditions. For instance, you record two actors talking to one another both standing on a busy street corner. The audio is okay, but there's a lot of wind and other ambient uncontrollable noises. As it's inadvisable to use the sound treated room in this instance, you could simply re-record that dialogue in an outdoor setting with less intrusive ambient sound. A good place to do this would be an alley, or a place where ambient city noise is reduced significantly but the overall outdoor vocal track vibe remains intact.

While it's always preferable to have your audio running directly into the camera with the use of cords and various adapters; giving you no significant syncing issues, there are drawbacks to this approach.

If for instance, you have a long-shot with actors far in the distance, it's impractical to have a cord running the length of the focal distance. You can, of course, use wireless devices. But in a city setting this is very difficult. There are lots of different types of electrical interferences around a city that limits the distance your sound guy can stand away from you. Also, the better wireless transmitters for this application can be prohibitively expensive.

I've found that while syncing issues will arise, making the post production process a little longer, it's worth it to have a field recorder or a portable audio recorder that operates separately from the camera. These are times when it's important to use a clapboard, or any other means of syncing your sound and video later. I've even found simply clapping in the frame of the camera while the sound is rolling (which picks up both the sound of the clap through my portable field recorder, and the actual video of me clapping from the distant camera) to be more than useful in syncing the video to the audio from the field recorder.

The Marantz PMD-660 Digital Field Recorder is my personal favorite. For only around $500 the unit has two separate XLR inputs, a line input (minijack) and a headphone jack for live monitoring. And most importantly, provides phantom power. It requires a CompactFlashCompactFlash card out of the recorder, slip it into your computer (if your computer has a media reader), and drag the audio files (in WAV or MP3 format) to your desktop. Or, you can connect the recorder directly to the computer with a USB 2.0 cable. Either way, it will make your workflow very smooth. Its only drawback, is the fact that it runs on four AA batteries. While it still comes with a power cord that you can plug in anywhere, you'll usually want to bring extra sets of batteries if you know you will be filming somewhere remote. A good way to extend the battery life of this unit, is to not constantly keep it in "pause" mode. The pause mode will not record but still give you a live feed from the microphone into your headset. It's best to simply stop the recorder after a take. The recorder automatically makes a new file every time you hit record and stop. It will also date stamp files so you can see the order in which files have been recorded. A great additional feature, is an input level control knob, which allows you to change the input level of both input channels independently.

It's also important to be organized about it. Make sure you and your cameraman are on the same page as far as what take you're about to shoot so you can simply record the take number into the recorder before you begin filming. Of course the best way to do this is to have a clapboard with the scene and take written on it - while at the same time recording the same information with your voice - into the field recorder, as I said before.

Considering all techniques, it's important to recognize the various microphones most commonly available for use.

The most commonly used microphones and their "pickup" patterns:

(The black lines over the microphones show the direction and range from which they all pick up sound)

Cardioid microphone This is by far the most common microphone type. As you can see, the pickup pattern is heart-shaped. This microphone works well at close range and has a slight pickup pattern towards the bottom of the microphone. This microphone, while common in many various brands and price ranges, is rarely used in video and film application because of its limited range of pickup.	Omnidirectional microphone This microphone is quite common as well. As you can see the pickup pattern goes in all directions. It will pick up sounds behind the microphone, beside the microphone, and of course in front of the microphone. While this microphone is never used in recording dialogue in a scene, it has a very important role in the audio for video realm. It's excellent for recording ambient sounds because it records in all directions. It's a good microphone for picking up ambient sounds on subway trains, busy streets, mall interiors and all other ambient uses. You always want to use an omnidirectional microphone separately from recording the dialogue in a room. Complete silence is needed for your ambient track. You don't want any unusual noises or unrelated speech "bleeding" into your dialogue track. Remember that you will be using this ambient recording to layer under your characters' dialogue track.	Bidirectional microphone Relatively less common than our first two microphones, the bidirectional microphone is very useful in recording ambient sounds. Mainly because (as you can see in the pickup pattern) it will record separate sound information from two opposite sides of the microphone itself. More importantly, these microphones can usually record in stereo. One-upping the omnidirectional microphone, its ability to record stereo sounds makes recording an ambient track more realistic. The environment will have a stereo field and more closely mimic the way human ears interpret sound.	Hyper-Cardioid Microphone A lot less common, this microphone has an extended forward range of pickup. It is used mainly for live performances and other instances where feedback and other unwanted sounds are mostly eliminated. As you can see, it has a slight rear pickup which does affect the rustling sound caused by the handling of the microphone itself. It's only acceptable application in video or film, is news reports or any other video project where it is appropriate for your subject to be holding a microphone to their mouth. Despite its extended range of pickup, it is still not the preferred method of recording dialogue in character-based filming.

Below is a microphone in the family of microphones known as "condenser". Condenser microphones require a small amount of voltage to work. A lot of the time these microphones have places in them for batteries. A condenser microphone, will run on a battery for a limited time depending on the model and make. But usually they make use of something called "phantom power".

Shotgun microphone This specific condenser microphone is called a "shotgun mic" or a "super directional" microphone. You'll see that the pattern of this microphone (simplified for illustration purposes) has a narrow pickup range. In fact, this specific microphone got its name from an actual shotgun's (pictured below) discharge pattern. Because the shotgun fires cartridges that release many bullets at once, the dispersal pattern widens the farther out the bullets go. Or, the little bullets "spread out" after they leave the barrel of the gun. While shotguns are only good for close range applications, in a similar way shotgun microphones are as well. The farther away you are from an actor's mouth with this microphone, the more you will pick up the noise from behind him and from either side of him. Nevertheless, this microphone is the best for picking up sounds around 6 feet away. Cardioid microphones can't even get close to that range, while you'll still get a lot of ambient noises it won't be nearly as bad as other microphones. But you want to get as close as possible, this is why you often see shotgun mics being held from a boom over the actor's heads. It's good to get as close as you can, without the microphone being seen within the frame. Sometimes miking from below works just as well. I've even had situations, in very wide shots, where I've had to hide the microphone in front of the actors and pointed at their mouths. I would use a rock or a garbage bag (full trash bag for a city street scene) or anything I could get away with that would not look strange in the scene.

Phantom power is the preferred alternative to using a battery within the mic. Phantom power is generated wherever you plug in your microphone. Provided the device you use, such as a mixing board or a portable field recorder, offers the phantom power feature. The device sends electrical power through the cable to the microphone. This only works if you use a standard XLR cable. This is the cable you should be using anyway for professional applications.

 

There is an additional cover you want to use on top of the wind cover that comes with the microphone. This is most commonly called a "softy", or a less friendly name a "dead cat". It's generally a very fuzzy and animal fur-like covering for the microphone. But they're usually very expensive, and not always designed well for every microphone.


Shotgun microphones, even models more expensive than my own, are very much affected by wind. Not just at the top of the microphone; but on the sides, and even the very bottom - where the microphone hooks on to the microphone cable. It's important to make sure, you cover the entire microphone with your softy. I would even recommend putting a regular white sock under the softy.

A wonderful and inexpensive alternative to the softy is a fuzzy sock. Usually made for women as a kind of thick winter alternative to slippers, it does an amazing job at cutting wind rumble. Especially when you layer the microphone with its original cover, a regular sock, and a fuzzy sock. It's also recommended that you pull the sock all the way down past the connector to the microphone and duct tape it to the cable itself. While this does not look pretty by any means, it does an incredible job.

This picture shows my home grown version of a fuzzy-enabled shotgun microphone. It's layered with its original wind cover, a regular white sock, and the fuzzy sock that runs the length of the microphone itself and even past the cable connector. While it may look a little strange, duct tape does an incredible job at keeping wind that might come from behind you out of the microphones' pickup pattern.

The connector clamp pictured as well, is a standard shock mount to reduce rumble from sudden hand movements while holding the microphones' shock mount or mounting the microphone on the boom pole.

Below is an audio sample from the same microphone setup. It was a relatively windy day and there was a lot of exterior noises. Children talking, cars going by, and even a school bus passes by while I recorded this segment out the window of my third story apartment from the fire escape. The subjects are about 50 to 75 feet away from the microphone. And even though this isn't dialogue quality audio by any means, it gives you a good idea of the microphones' wind resistance and pickup pattern.

Audio sample: children walking and talking and a school bus passing.