Sound for Video Session: Troubleshoot, Mobile, Richer Sound, Noise, and ADR
In this week's Sound for Video Session we run through several questions:
- How to troubleshoot
- Does the Kaotica Eyeball really reduce room reverb for recording?
- Best gear to record podcasts on the road?
- How do I make my recordings more “full-bodied”?
- What can I do when I’m recording an interview and a snow removal blower is working outside?
- Which microphone should I use for ADR?
Gear used or mentioned in this episode:
Electrovoice RE20 Dynamic Microphone (Voiceover for this session was recorded with this)
Tascam DR-60DmkII Audio Field Recorder
Antelope Orion Studio Audio Interface (Voiceover for this session was recorded with this)
Copyright 2017 by Curtis Judd
Sound for Video Session: Clean Noisy Dialogue Sound with Adobe Audition
In this week's Sound for Video Session we run through several techniques you can use to reduce noise in very noisy dialogue sound recordings for film. We use a clip recorded on a busy urban street where we could not get as close to the interviewees as we would have liked.
Gear used to produce the short film and this episode:
Audio Technica AT4053b Hypercardioid Microphone - used this to record the interviews out on the street. Works well as long as you have a good shock mount and wind protection (see Cyclone below)
Rycote Cyclone Windshield and Shockmount - this is what prevented the wind from blowing across the microphone capsule and making that low frequency, distorted sound.
Sound Devices 633 Audio Mixer/Recorder - my go-to recorder/mixer
Electrovoice RE20 Dynamic Microphone (Voiceover for this session was recorded with this)
Antelope Orion Studio Audio Interface (Voiceover for this session was recorded with this - couldn't be happier. By far, the best audio interface I've owned)
Sound for Video Session: Lavalier Mics, Air Conditioning, Music Videos
This week we answered sound questions from several of you including the following:
- 3 questions about lavalier microphones
- How to deal with noise like air conditioning
- How to record/shoot music videos
Gear discussed and used to produce this episode:
RODE VXLR 3.5mm TRS to XLR Adapter
Tascam DR-70D Audio Recorder (4 inputs)
Electrovoice RE20 Dynamic Microphone (Voiceover for this session was recorded with this)
Antelope Orion Studio Audio Interface (Voiceover for this session was recorded with this)
Sound for Video Session: Reduce Reverb, Lavalier Clothing Noise, Record Live Acoustic Bands
In this week's episode, we cover questions on these topics and more:
- How to reduce reverb in rooms with lots of hard surfaces
- Are there any special techniques for reducing clothing noise when hiding a lavalier mic under clothes
- Thoughts on recording live acoustic music groups
Here are links to a few videos we mentioned:
Using sound blankets to reduce reverb
Audio Recorders
Microphones
Sound for Video Session: Preventing Noise When Recording
Last session we talked about the sources of noise and how to measure it. This week covered a few strategies for reducing noise while recording: Sound blankets and high pass filters.
Sound for Video Help Session: Noise Sources and Measuring
This week we spent a while talking about the potential sources of noise in audio recordings and how to measure it using Adobe Audition. When I first started recording audio, I didn't realize how important the recording location was to ensuring a clean recording. One of the biggest things you can do to reduce noise in your recording is to either find the right location or hang sound blankets (or any blanket that will dampen audio reflections off of the walls).
But here we also talk about signal chains and where noise can creep into your recording along that signal chain. While the noise performance of your microphone and preamplifier are important considerations, they're not the only consideration so don't stress too much about those. Make an informed decision before buying but then move on and don't stress if your noise floor sits at around -60dB.
Most of the new recorders and microphones will easily get you into this realm, even prosumer mics and recorders. Let me know if you have any specific questions on which may be a good fit for your particular situation.
Next week we'll cover options for reducing noise.
Zoom F8 Noise Performance: One Simple Test
Jim Braly asked a good question about the Zoom F8 field recorder:
A question about how quiet the preamps are -- I'm impressed that the Zoom has 75db of gain (compared to 66 on the Sound Devices 7-series recorders). I found that the last 6db on a 722 SD recorder was not very usable, as it got pretty noisy above +60db of gain. And that last bit of db helps for quiet dialogue, or on wider shots when the boom mic cannot get as close to the actors.
How about the F8? What is the noise floor like if you crank it to +75 with the mic in a quiet room? (No recording of dialogue, just the room tone and the self-noise.) Do you hear a lot of hiss? At what level would this hiss be? Louder than, say, -50db if you are measuring the audio file in iZotope RX? If the F8 does get noisy at high gain settings, at what point does it become unusable? Maybe above 70db of gain? But would, say, 66db of gain sound good?
Of course, I'm wondering how the F8 specifically compares to Sound Devices in the noise floor department, as I think of their recorders as the gold standard.
I ran a Shure SM58 into the Zoom F8 via a 25' ProCo XLR cable with Neutrik connectors, set the gain at +75dB and recorded my basement studio. This room is not perfectly silent and not perfectly treated in an acoustical sense. But I do have a sound blanket hanging to one side, exposed batt insulation in the ceiling and an old duvet on the floor.
Looking at the silent section, I measured the noise floor (this is the sound of the room + the self noise of the mic and the F8 recorder) at -63dB RMS. In my final produced audio, I usually aim for the "silent passages" to sit at -60dB or lower. This seems acceptable and is a rather impressive result for the Zoom F8.
Looking at the spectral chart, it appears that of the noise that is present, the majority of it is in the 100Hz and lower range which should be reasonably straightforward to reduce with a simple high-pass filter. There is some spread throughout the entire spectrum, but very little. (in the screenshot above, I measured the section from 35 to 39 seconds. Just prior to that, the mic was able to pick up a few notes from my wife's violin upstairs.)
Quick Sound: Noise Reduction with Audacity
If the sound for your video is a little on the noisy side, you can clean it up using the free audio editing app Audacity. Audacity comes with a noise reduction plugin that makes it quick and easy to cut back the noise so that your audience can focus on your story or message. Here’s a very quick look at how to use the noise reduction effect in Audacity.
This is the start of a new series of tutorials I'd like to try called Quick Sound. The idea is to keep each piece short and focus on teaching a very focused element of audio recording or post processing. Does this sound interesting to you?
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