Microphone Buyer's Guide 2008 (page 2)

Pickup Patterns

Then there are the types of pick-up, i.e., how do they receive sound waves? Included in this group are:

• Unidirectional: This microphone picks up sounds from one direction, usually from the front. A unidirectional mic is ideal for recording an interview or dialogue. Types of unidirectional mics include the cardioid, hyper-cardioid and super-cardioid, so named for their heart shape. They are extremely sensitive and found mostly in handheld mics.
• Bi-Directional: These mics pick up sound from the front and back of the mic.
• Omnidirectional: This mic picks up sounds from many directions: front, back, left and right. This mic is the best choice for recording wild sound.

Mono and Stereo Microphones

• Mono: A mono mic sends a signal to one channel only. It is perfect for recording an interview or dialogue in a scene. In post production, you can easily convert this audio to stereo by panning it to the center on your audio track on your timeline.
• Stereo: A stereo mic sends audio signals over two channels. It is great for wild sound, such as a crowd of people, cars, natural sounds, etc. Of course, you can use either mic for any type of sound you need to record.

Balanced and Unbalanced, Cables and Connections

• Balanced: Balanced mics and connections can help cancel out interference, thanks to the wires within the cable: hot (positive) and cold (negative) wires for the signal, plus a ground wire. This allows cables to be longer and have little to no interference. The most common connection is XLR.
• Unbalanced: Unbalanced mics and connections have only a ground and one signal wire, which is less likely to cancel interference. You need to keep these cables at a smaller length. Most non-XLR cables, mics and connections are unbalanced.

Heath McKnight is a filmmaker and writer who co-wrote the book, DV: What You NEED to Know, Volume 2, from VASST.

Manufacturer's list

To download a PDF of Manufacturer's list, CLICK HERE.

Side bar: Sound Equipment

After choosing which microphone best suits your needs, it's time to take a look at other equipment that's necessary to getting great audio.

• Headphones: A great pair of headphones is vital to monitoring the audio. Too many times, the sound or camera operator relies solely on the camcorder's audio-level meter. That's fine for ensuring the sound is hitting the right level, but what if the sound is nothing but distorted static? When it's time to go into post production, imagine the shock of hearing horrible, unusable sound. We've witnessed it many times. If you are still unsure about using headphones, think about this: would you keep your eyes closed while shooting?

• Field Mixer: A field mixer can be an important tool, but it isn't entirely necessary and can be difficult to use if you're shooting solo. There are many brands of mixers and therefore price points, so we recommend something with at least two XLR inputs and outputs, at least two 1/8" jacks (input and output) long with at least one headphone jack. You can also use a great mixer during post production when you are not in the field. A field mixer usually provides phantom power.

  A common mixer will have a volume knob or slider, along with controls to manipulate bass, treble and more. If the mixer doesn't allow batteries, it's not the best for field work. A great mixer allows the use of both batteries and AC power. A strap makes it easy to sling it over the shoulder for easy carrying. A bag that the mixer can easily fit into can help protect it, and it can store cables, adaptors, etc.

  If you're doing serious sound work, consider a separate audio recorder, such as a Flash-based device that can handle multiple frame rates (such as 24 or 30 frames per second) and time code recording. This isn't necessary, but again, if sound is primarily what you're doing, this may be a good investment.

• XLR Cables: Most mics have XLR inputs and outputs. XLR cables are readily available, even at the local electronics store. However, I'd recommend that you buy them from a video specialty shop, because of the importance of the manufacturer's cable wrapping. A cable wrapped the wrong way can fail quickly, even if you purchased it new. There are 1/8" and 1/4" cables, but professionals commonly use XLR.

  A cable length of 25 feet or less is perfect, but having a longer cable is good if it's balanced. For balanced or unbalanced, see below. Keep all power cords off the XLR cables, even though they are insulated. Don't run the risk of creating a hum in the audio with a power cord sitting on the XLR cable. I also recommend using only batteries versus AC power when powering up the camera. It's just one more power cable that could ruin a great take of audio.

• Adaptors, Extra Cables, Batteries: Always have adaptors, extra cables and batteries standing by. Some adaptors include those that allow 1/4" plugs to fit into a 1/8" jack, along with XLR-to-1/4" or -1/8" jacks and vice-versa. These can fit in the mixer bag. When a battery dies, the audio can sometimes fade slowly over time, thus ruining many good takes.

• Windscreen: Many mics include a windscreen, which helps block out one of the most annoying problems when it comes to recording sound: wind. On a windy day, the sound will come out like a constant roar or rumbling sound, ruining the take. Cameras often feature a wind cut option that can help reduce the rumbling wind, but there are compromises: dialogue will sound tinny, because the low frequencies are being cut out. In some cases, you should cut wind in post production, where you'll have more control.

  An optional piece of equipment is the pop screen or pop filter, which sits in front of the mic. This helps cut back on "popped" audio, as the subject talks. You would commonly use this for recording vocals or voiceovers. Stretch a piece of nylon over a ring for an affordable option.