Isolationism

This is the first post in what will hopefully grow to become a small series about recording sound effects (especially the natural variety) with a special focus on use in environmental audio simulations. The reason for this little series is directly related to my hobby of designing such simulations using Boodler, an excellent, undervalued, and largely unknown piece of software for doing exactly that. My hope is to spread the word about this great piece of software to everyone from the casual listener to the sound professional in the hopes of meeting other enthusiasts to learn and share with.

The best way to get sounds for use in such environmental audio simulations is to record them yourself; while other means exist of collecting sounds, they may be of inferior quality, inappropriate for some reason or other, and sounds from other sources are probably use- and copy-restricted—After all, part of the fun is being able to share the fruits of your labour with others!

I am far from being a sound engineer, and so far have been only marginally successful in my attempts to make sound effects recordings for my own use. Hopefully this in-depth article will help you understand what I have learned; if you have your own tips, suggestions or corrections please don’t be afraid to share!

A Difficult Choice

The decision of which microphone to buy is immensely difficult; there are thousands of choices out there, and most of them range from the expensive to the outrageously expensive. The variety of technical jargon doesn’t make it any easier to choose, either; The unfortunate reality is, if you want to make good sound recordings, that little beige microphone that came for free with your sound card isn’t going to cut it.

What I’ve discovered to be the most frustrating aspect of recording is this: Just like cameras (only drastically more so), microphones don’t ‘hear’ sound the way we do. Not only are our ears able to process a broad range of amplitudes and frequencies, but the process is highly selective, too—our brains can help us focus in on certain sounds while selectively rejecting others; like many of our senses, hearing can become accustomed/de-sensitised to repetitive or continuous sounds.

Therefore, the microphone you choose is of course going to impact your ability to record different varieties of sounds: mics designed for speech and certain instruments may lend richness to the character when recording them specifically, but are likely to sound awful trying to record a wider range of sounds (that are bass- or treble-heavy, or that have a broad dynamic range, for example).

Cardioid and Hyper-Cardioid Pickup Patterns

In a similar vein, microphones designed for studio and live performance use are typically designed with a high rejection-rate (such as cardioid and hyper-cardioid pickup patterns) beyond a very short distance from the microphone to avoid picking up ambient/crowd noise, monitors, and other instruments; Unless you’re able to get within a few inches of your subject with one of these, your sounds are going to be virtually inseparable from the background hiss.

Cardioid microphones do have one large benefit in that they are frequently considerably less expensive than other types of microphones, and are also easy to find, being one of the most commonly-used varieties (as they are considered ideal for recording the human voice).

Super-Cardiod or “Shotgun” Pickup Patterns

There are more specialised types of microphones for recording items at a distance, such as the super-cardioid or “shotgun” microphone—but these tend to be large, difficult to handle (often requiring vibration-absorbing mountings and windscreens or “zepplins” to prevent the mic from picking up even a light breeze as heavy rumbling), and are ruinously expensive, usually ranging from $400 and up (before the cost of the additional support items). These are great to have for nature recordings, though, as they have a long range but are highly directional in nature.

Condenser Microphones

Condenser microphones are the variety that behave most like our own hearing in most circumstances: They are designed to behave as nearly an opposite to the cardioid, picking a wide range of sounds in a general area, adapting somewhat to the level of sound pressure available. These are frequently used in performance settings where it is impractical to mic each member of a large group individually, or where the “overall” sound is more important than having granular control over each individual element. These are also the best microphones for picking up ambient sounds or for targets where mere proximity to a larger subject is sufficient for a recording.

If you’re still a bit fuzzy on which type of microphone to get, chances are the condenser microphone is your best bet as a starter, unless you have money to burn and can afford a good quality shotgun microphone (or you already have access to one for free).

There are yet other options to consider when selecting a microphone:

Power

Many microphones require a power supply to convert sound pressure into an electrical signal (the most notable exceptions are some cardioid microphones, which don’t require any power to provide a signal).

The two most common means of supplying power to microphones is either by a battery directly inside the microphone, or by phantom power, which is a fancy turn of phrase for the power being supplied by the recording device/mixer that the microphone cable is connected to. If you’re not certain what you want, you’re probably better off going with a battery-powered device: It will work with more recording devices (as nearly every recording/mixer device that supports phantom power will also work with self-powered devices), and it will put less strain on the battery of your portable recording unit, giving you a longer recording time. Don’t worry too much about battery lifetime; usually the trickle of power required for most microphones means a single battery is good for days of recording (so long as you remember to switch your microphone off when you’re done).

Note that some microphones are “smart” enough to switch from using an internal battery to phantom power if it is available.

Size

It seems silly to mention, but hand-holding an unwieldly or heavy microphone during a long field recording may not be something you’re considering when you purchase the mic. Unless you’re planning to haul a tripod around with you, though, it’s worth having something you aren’t going to mind lugging around and holding steady for long periods of time.

If size is a big problem for you, consider buying miniature microphones of the type designed for lapel or concealed use—just make sure to get the right variety to suit your recording need; a wireless lapel mic is probably considerably more expensive than what you’re looking for and not a very good fit as you will almost certainly be carrying the recording device around with you also, making the wire a moot point.

Stereo

While most microphones record to a single audio channel, some are designed to record in stereo while others are designed as a pair intended to be positioned for binaural recording. While stereo mics can be helpful for recording certain types of events (and are seldom a drawback—expect for price—as you can always use only a single channel or record to both and drop/combine channels later during the editing phase), binaural recording devices may prove less useful to you unless you intend to use headphones to play back your recording.

Balanced vs. Unbalanced

Most professional audio gear is designed for use in a balanced system as they are better for working over long distances and negating the effects of EM interference. However, this capability is not essential to a recording setup which is intended to use a short run of cable (e.g. a metre or two) in an environment which is less likely to have high levels of interference (natural settings).

Balanced recording gear is still generally a good idea to purchase as it is more flexible since it can be used in both balanced and unbalanced systems effectively, however this can add significantly to the bulk of the device because of the XLR cable connection and the thicker, often-shielded cable itself, meaning the balanced option is frequently unavailable in smaller/miniaturised mics.

Cabling

It is not uncommon for microphones to ship with their own cables, especially if they have a special design (such as miniaturised microphones or special-use sets, like stereo mics). It’s a good idea to find out if your mic comes with a cable or not, and to determine whether or not it’s appropriate for your intended use.

The most important thing to do here is to know exactly what kind of connector your mic requires, and—more importantly—what you’ll be connecting it to. Different devices support different kinds of connections, and you may have several options available to you; for example, if your recording device and microphone both support balanced recording via an XLR cable, you’d be crazy to plug your microphone into a 1/4" phono jack without very good reason!

Windscreen

A virtually essential tool for all manner of outdoor recordings. Unlike your eardrum, which is protected from wind noise by being deep within your ear canal which is itself filled with thousands of tiny little hairs, a microphone is highly susceptible to recording an obnoxious rumbling sound when exposed to even light winds. Shotgun mics are the most susceptible to this type of noise, but other mics can be impacted too depending on their type, design, and environmental conditions.

The solution is a windscreen, which is an acoustically transparent cowl that dissippates the wind from affecting the microphone while allowing sound to penetrate.

The big drawback to windscreens are the unbelievable price associated with the devices. The good news is you can make your own windscreen for a fraction of the price of a commercial unit if you are handy and have a bit of time to spare.

Camera Mount

A camera mount generally has two purposes: To attempt to vibrationally isolate the microphone from the operator, and to make holding and aiming the microphone more convenient. A useful camera mount for field work is the pistol grip, which is conveniently small and easy to hold steady for extended periods of time. Most windscreens—including the DIY design linked to above—incorporate a vibration-isolation mechanism as part of the unit.

Parabolic Dish

The purpose of a parabolic dish is the same as with other applications of the design: to concentrate waves collected from a greater area to a single point for collection. Although commercial units can be quite expensive, you can again build one yourself. The larger the unit, the better the reception (especially at low frequencies)—but don’t get too ambitious; you still want to be able to tote it around, and to collect sounds at frequencies at the lower limit of human hearing requires a dish that is probably bigger than you want to hold for any reasonable amount of time.

Commercial parabolic dishes frequently come with a vibration-isolating pistol grip as part of the design, and sometimes come with a built-in microphone (usually a cardiod-type for directionality, facing the dish of course) as well; windscreens are not always essential for these devices as the dish itself offers some protection to the microphone; if you do require one, be aware the zepplin type of windscreen won’t work; you’ll need something that covers the entire surface of the dish itself to be effective.

Be aware that commercial parabolic dish microphones will put you in the poor house as they frequently cost $1000 CAD or more. They are also rather difficult to source as they are highly specialised equipment that doesn’t see common use except in law enforcement, birding, etc.

If after all this, you’re still a bit fuzzy on which type of microphone to get, chances are the condenser microphone is your best bet as a starter, unless you have money to burn and can afford a good quality shotgun microphone (or you already have access to one for free). You can get by without a parabolic dish and a pistol grip, but a zepplin is strongly recommended—build one yourself if the cost is an issue.

That’s it for microphone selection—I hope this article has helped you select an appropriate microphone with which to make your own ambient sound effect recordings. In my next Boodler article, I’ll cover some of your options for devices with which to make field recordings.