AUDIO RECORDING - BASICS

Transcription

1 AUDIO RECORDING - BASICS

2 Some Audio Terms XLR - XLR connectors are used with balanced lines for optimal interference rejection. An XLR connector's pins usually point in the direction of signal flow. Higher quality connection for audio. Use these if possible over other connections Wildtrack Audio recorded in a specific location to act as background audio Stereo Left & Right channels of audio Stereo 5.1 (or just 5.1 ) Common name for 6 channel surround sound system Mono Audio recorded to a single track Diegetic Sound Audio which appears synced and onscreen (i.e. an actor talking, a dog barking, sounds made by on screen objects) Non-Diegetic Sound Audio added for effect (i.e. music, voiceover, sound effects) Foley Sounds recreated to match on screen audio (footsteps etc.) See the film Berbian Sound Studio Room Tone At the end of a shoot in a particular shoot you may want to record a few minutes of room tone (the sound of the room with no other audio such as a fridge buzzing, traffic passing outside) to use later in the edit. Sync Sound - Audio is recorded to the same file as the picture.

3 Microphone Types - Shotgun Shotgun mics are often the most commonly used in film production. These mics are often a longer stick shape and pinpoint audio at a narrow angle from the front of the mic, some from the sides and a small amount from the back. Its high degree of directionality means that the shotgun mic must always be carefully pointed at the desired sound; a slight turn of the mic to one side or another will cause a loss of sound pickup. If you want to record a very specific noise from a specific direction use a shotgun mic. Shotgun mics can be attached to a boom pole and windshield then pointed towards an actor/audio source. Shotgun audio field

4 Microphone Types Omni-directional Omni mics are often used to record ambient sound on location. These microphones pick up audio from a wider angle around the mic. Use an omni if you want to record a general wildtrack audio i.e. the sound of the beach encompassing waves, gulls, voices etc. Omni audio field

5 Microphone Types Condensor (vocal) Mic Condensor (or vocal) mics are used for recording voiceover etc. in a controlled (quiet) environment. When used with a shock mount and pop shield (a material disc which sits infront of the mic) these mics create a clean, warm vocal sound. Condensor audio field

6 Microphone Types Radio (or Lavalier) Mics These tiny, compact mics (wired or wireless) are used for recording vocals, omitting background noise and focusing on picking up the speech of the user. Generally used for recording interviews but radio mics are also useful for recording dialogue if the shot composition is extremely wide with no room to conceal a boom operator. Also very handy for tracking shots where the person is moving about. Radio mics usually operate on a certain frequency so make sure they are set to the right one, otherwise you could end up with radio interference from police/ambulance radio channels etc. Use a lavalier mic for interviews, especially if the location is likely to be noisy.

7 H4n Zoom Recorder The Zoom H4n is a small, portable digital audio recorder which runs from battery or mains power. It s designed for studio use and field recording. It can record around 6 hours of WAV 48KHz audio on a 4GB SD card. The Zoom has high quality built in mics (which can be adjusted to record from degrees). The Zoom also has XLR inputs for plugging other mics in (you can plug a radio mic into it and record the audio directly onto the card). You can also use the built in mics and an external mic for recording a specific sound and the ambience at the same time (ie if you are recording a voiceover on the beach and to include the background or recording 2 people talking at the same time). PHANTOM POWER Some mics can be powered from the unit that they are plugged into, others need a battery supply. If phantom power option is turned on within the Zoom menu this can lead to feedback/distortion. RECORDING When recording with a Zoom keep an eye on the recording levels. If you initially press record and hear the audio this doesn t mean the zoom is recording Press record again to start recording (you ll see the time ticking over on the screen). 4 CHANNEL You can record to 3-4 channels on a Zoom. This may be useful for recording a very specific sound but also keeping some of the background audio. To do this select Menu>Mode>4CHAN. You can now use the built in mics and plug up to 2 external mics into the XLR inputs (adjust audio on both channels to mix the sound). LEVELS STAMINA MODE Try to keep recording levels around -12Db. This will ensure the audio is balanced without distortion yet still audible. Located in the battery compartment this switch lets the Zoom run for longer. However, it reduces it s settings and options. MONITORING However you are recording sound and with whatever kit it s vital to monitor (plug headphones in) the audio at all times (if you can)

8 DSLR + Audio Built-In (Onboard) Microphones + recording Sync Sound on a DSLR Video cameras and DSLRs often have built in microphones. Though some can be ok most are relatively poor in comparison to radio/shotgun/ omni mics. DSLR onboard mics are especially bad quality if you are planning to shoot with a DSLR and audio is important use a DSLR mic such as a RODE VideoMic (a small shotgun) and plug it into the mic socket on the side of the camera. This will override the DSLR onboard mic and provide much better quality audio. If you are planning on shooting a piece that relies on lots of sync sound i.e. a documentary you may want to think about using a camera with built in XLR inputs such as an XDCAM or C100 MKII. If recording audio to DSLR make sure you check the levels before shooting. (Menu>Audio Settings).

9 Syncing Sound with DSLR There are a few options: 1/ Use a DSLR Rode Mic (fairly good quality much better than the DSLR onboard mic) 2/ Record the audio on a Zoom H4n and sync the audio up in post later 3/ Run the audio from a Zoom into the DSLR 1/ Run an output from the Zoom headphone/line out socket into the DSLR mic input 2/ Make sure DSLR audio level is set to Manual & level is 1 notch from 0 (Otherwise you ll get buzzing & distortion) 3/ Set Rec Level & Headphone level to 55 on Zoom SYNCING FOR POST PRODUCTION Using a clapperboard A clapper board gives you a visual representation of when the audio starts on the image and the Zoom. You can then sync up the better quality audio with the image. If you don t have a clapperboard then ask the person in frame to clap their hands together at the start of each shot.

10 Boom Kits Boom kits comprise of: PISTOL GRIP (A handle for screwing the mic into this can be handheld or attached to: A BOOM POLE (an extendable pole - pistol grip + mic attaches to it) WINDJAMMER (optional cuts wind bouncing off the mic body, causing interference) WINDJAMMERS are sometimes called: Dougals, Dead Cats, Softies. XLR Cable to feed signal from microphone to Zoom/Camera etc. MIC (usually a shotgun)