The Hierarchy of Recording Good Audio

The Hierarchy of Recording Good Audio
Build your cathedral of sound one piece at a time. Start with a strong foundation and make sure you have taken care of the basics, including acoustics, microphones and mic placement.

Choosing your recording space is the place to start. If your acoustics are lacking, then everything down the line will suffer. A good microphone in a bad room is just that; you will have a great recording of a terrible space and a wasted opportunity.

Video Projects

You can choose one: a controlled indoor set, a controlled outdoor set, or a noisy setting. Picking between these will net you good usable audio or a greatest hits collection of the crowd and wind noise that means lots of ADR during post. It goes without saying that you always want control whenever you can get it.

It goes without saying that you always want control whenever you can get it.

Pick microphones that compliment your setting. You might be stuck on the noisy windy street. Use a lapel mic, try and hide it as best you can from the camera and wind noise. Even when you’re on set you might have to get creative. If hiding an omni-directional microphone in some furniture works, then do it.

Music Projects

Recording music gets tricky because you are now increasing the number of sound sources and microphones. Having a space that accommodates that is key because it will allow you to contain and isolate sounds when needed. Multitrack mixing falls apart when you start running into severe phase and leakage issues.

Audio Recorders

You can check out Videomaker’s guide to audio recorders for a broader selection. Purchase an audio recorder that suits your budget, but also leaves you some room to grow into. Being money rich and feature poor is frustrating.

Portable

The Zoom H5 is probably my first choice when thinking about portability and versatility. Providing a nice blend of six interchangeable microphone capsules, four track recordings, two XLR inputs, and DSLR mounting capability, the Zoom H5 is a more-than-capable mounted or handheld recorder that can be used for set and field recording. And the best part? It doesn’t cost a fortune.

Stationary

I have always had a liking for the Mackie Onyx 1640i, the top-end model of the series is a 16x16 FireWire mixer that is equally at home in the studio and on the road. I grew up with Mackie boards and love the accuracy offered by a tactile interface. Coupled with the flexibility offered by a DAW, you’ll have powerful combination for medium-sized recordings and mix downs, 16 XLR inputs and four Aux channels are more than enough to keep you humming along.

Microphone Brands

When it comes to general use microphones, my go-to brands have been Shure, AKG, Blue and Sennheiser. Between the three you have an excellent selection of small, medium and large diaphragm dynamic and condenser microphones, with Sennheiser also producing the venerable K6 series mounting platform for a variety of cardioid and shotgun patterned attachments. Both Shure and Sennheiser produce excellent lines of wireless microphones. Røde is also a good entry to getting started with lapel and shotgun setups.

More premium choices can be found through manufacturers like Neumann, Electro Voice, and Royer — not to say that the above manufacturers lack for high end models. You should always buy equipment that will give you the best return through its usage; brand names are only part of the story.

Microphone Types

A quick run-through the list gives us the following standard microphone types:
Dynamic – good for high level sound level sources
Condenser – more sensitive microphones that require phantom power and can be used for sources with higher dynamic ranges that require a more sensitive pickup
Ribbon – more fragile due to the nature of their design, but recent advancements have made them hardier and more flexible and able to handle higher sound levels; avoid phantom power at all costs with these mics

Microphone Patterns

The first three patterns can come in both dynamic and condenser flavors. Ribbon microphones tend to be either figure-8 or cardioid. Shotguns by design require additional power; a passive magnet cannot deliver that kind of sensitivity.

Omni-directional – full 360° pickup
Bi-directional or Figure-8 – front and rear pick up with good side rejection
Cardioid – heart shaped pattern with good front and modest side sensitivity; with super and hyper cardioid variants providing some rear facing pick up
Shotgun – extremely narrow and directional Cardioid pattern that is almost point and shoot, ideal for on-set dialogue capture, Foley, and ADR

Cardioid and shotguns both have their uses for dialogue. Omni and bi-directional microphones make great room microphones. Ultimately it comes down to the right microphone for the right job and using its pattern, tonal qualities, and design to do that. Dynamic microphones are great for high intensity sources like drums, but we also use condensers for picking up the cymbals and top half of the kit. Vocals and dialogue can sound good with both types; it ultimately depends on the tonal qualities of the source.


Microphone Placement

Time spent on this stage pays off in spades later. Getting to take the time and walk around with a pair of head headphones as you adjust your levels, or having an assistant engineer on hand while checking placements is the best way to learn what your microphones and placements sound like. Check the sound and levels individually and in harmony with the rest. Make sure your sound blends well, use your metering tools to check for phase correlation.

General Placement

Placement relative to your sound source is key. Play around with your positioning, move the mic around and take notes. Research your sound sources ahead of time; there are plenty of diagrams available that illustrate the sonic patterns of most instruments and recommended mic placements.

As a general starting place, there are a few basic rules and techniques that you should be aware of. The 3:1 Rule calls for any nearby microphones to be placed three times the distance of the first mic from the sound source. Close miking refers to placing a microphone 6-12 inches from a sound source and can be a good technique when trying to isolate a source. Multi-mic techniques include creating a stereo pair of microphones using an XY, MS, spaced pair or Decca tree formation and using multiple microphones on a single source. Ambient miking uses room microphones to capture the ambiance of the recording space and is great for capturing room tone to lay under your dialogue track.

Stereo Miking
Stereo Miking formations

Close Miking
Figure 1. Close miking of Mesa Boogie cabinet with Sennheiser e845s dynamic super-cardioid and Bluebird condenser cardioid.
Figure 2. The Sennheiser is positioned about 5 inches from speaker cone and is off-axis from the center, providing a crisper and less muddy sound.
Figure 3. Top down view of the Sennheiser and the Bluebird. The Bluebird is about 10 inches from the speaker cone and while still close miked provides a more open sound and is again off-axis from the center. In this case the guitar tone and performance had sufficient low end and didn’t benefit from direct on-axis placement.

Recording Settings

You want to get your recording settings right when creating your project. Having to change sample rates or frame rates down the line is a bad sign. While DAWs have become significantly more forgiving and capable at converting sample rates, frame rates are something you should absolutely think about at the beginning.

Bit Depth

The last 10 years have made 24-bit recording the standard on the majority of recording equipment and DAWs, so this should be enabled regardless of your project type. You can always dither down to 16-bit when you export your files.

File Types

The two main lossless file types are WAV and AIFF. Professional applications will have the Broadcast Wave File (BWF) as an option, which stamps WAV files with timecode data and makes importing files a whole lot easier when you can snap them into their original positions.

Sample Rates

Some engineers, myself included, like to record at 48KHz because of the extra dynamic range this affords us. Bandwidth wise, it’s nearly identical when recording 32 channels through a FireWire setup. Thunderbolt is the latest iteration in a line of PCIe based interfaces that companies like Digidesign Pro Tools, Universal Audio and MOTU have been using for their high end recording lines.

This is especially relevant with all the recent conversations centering on High Definition audio, sample rates of 88.2, 96, 176.4, and 192 KHz. Without going into too much detail, audio resolution and video resolution are two different things. While increasing the resolution in both respects will capture more data, higher audio resolution does not have nearly the same effect on quality as does higher video resolution. It will however consume more disk space and processing resources.

There has been a lot of hype about HD Audio in the last two years, especially surrounding the release of the Neil Young backed Pono music player. The initial pitch seemed promising because of the promotion and distribution of uncompressed music files. As the project developed, the conversation switched to super high fidelity 192 KHz mixes and made the whole idea begin to sound less cohesive and more like a marketing gimmick. If high sampling rates were the future, we would be there already. As it is, there are an increasing number of artists making 44.1 KHz 24bit FLAC files available for sale, which I think is far more relevant to people seeking out high quality uncompressed files.

Unless you are recording very specific material that needs a lot of editing at a sample level, it’s best to standard sampling rates.

Project Types

Keep an eye on your destination and work towards your target delivery medium. These are choices that should be made early on. You can always scale files down, but never back up.

The three most important settings to consider in video are your sample rate, frame rate, and bit depth. Video project sample rates are almost universally 48KHz, but 96 KHz is not unheard of especially with surround sound mixes. Frame rates will depend on your target medium; these are the most common ones are 24fps for cinema, 25fps for PAL broadcast and 29.97 fps for NTSC broadcast.

There are more exotic frame rates of 48 and 60 frames per second, I’m sure we all remember the opinions surrounding The Hobbit being shot and screened at 48fps. Meanwhile 60fps is popular with the action-cam and video game streaming audiences.

Results

Now that you’ve made considered choices regarding the recording environment, audio recorder, mic type and placement and your recording settings, you’re ready to capture clear, clean audio for your project. Building your cathedral of sound from the foundation up ensures you’ll get great results, every time.

Blag spends his time between web development, IT, and music. His background is oddly enough in the same things. Blag works in IT and is a contributing editor at Videomaker magazine where he mainly focuses on audio related columns.

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Blag
Ivanov
Tue, 02/07/2017 - 9:20am