Wired for Sound

Too many videos suffer from bad sound. Common symptoms include distant, tinny voices surrounded by ambient noise–appliances, air conditioners and even passing traffic. Another warning sign: when it’s time to play back your tapes, you have to turn the TV volume level up annoyingly high to hear your audio.

If you recognize any of these signs in your videos, you can probably point to the on-camera microphone as a likely cause.

On your next project, help bring the soundtracks back to good health by using a separate microphone instead of the one on the camcorder.

How do you choose a mike that will improve the videos you make? Read this guide and find out.

Beyond the Camera Mike
Camcorder makers had the best intentions when they put the microphone on the front of your camera.

They knew that an interview with grandparents at a family reunion, or shots of a baby daughter saying her first words, wouldnt entertain an audience without the sound of their voices on tape. To let even novice users easily record sound, companies put a basic mike on every model.

To its credit, the on-camera mike comes in handy in a number of situations–like those funny moments around the house, or the late-breaking news that you find yourself shooting for the local TV station.

In moments like these, you rarely have time to set up a tripod, let alone worry about the sound. Thats where the on-camera mike really helps. It effortlessly records how the event sounds, so your audience has something to hear as well as watch. No wonder we grow so dependent on it.

Despite the convenience and ease of use, the built-in camcorder mike doesnt usually record good sound; not because its a poor mike, but because it always sits too far from the action to record it well.

Any microphone works better when you put it close to the source of the sound you’re taping. As a general rule, the closer the mike, the better the sound.

Because the built-in mike always stays on the camera, it cant get any closer to the subject than the camera does. Thats usually too far away to get good sound.

To get a microphone close to whats happening, you dont have to put the camera right in the middle of action, or right in the face your interviewees. Instead, you can purchase a separate mike and place it as close to the action or person as possible. Plug the output of that external mike into your cameras microphone input. Presto: youve just made a giant leap toward great sound in your video.

Sound Like the Pros
Any experienced videomaker will tell you that using a separate mike instead of the on-camera mike separates the serious videomakers from the amateurs.

Its a simple, relatively cheap way to make your work stand out. If youd like your videos to sound one step closer to professional, get an external mike.

How do you know which mike best matches your gear and your projects?

First, you should know a bit about the different mikes on the market. Each one works, looks and sounds a little different than the others. Knowing those differences can help you pick a mike to make your videos sound their best.

Next, evaluate your budget and choose the best one you can afford.

Sounds easy enough. Lets get started.

Mike Features
All mikes do essentially the same thing: convert sound waves into electrical energy by means of an element called a pickup. Your VCR or camcorder then amplifies the mikes electrical signal and records it on the tape’s audio tracks.

But even though they do essentially the same thing, they vary in size and shape based on the functions they were intended to perform. For this reason, mikes come in three basic physical styles.

Handheld mikes are exactly what the name implies: easily held in your hand.

Lavalier mikes, also called a lavs, are much smaller (about the size of a pencil eraser). They clip unobtrusively to ties and coat lapels for up-close recording of voices.

Zoom or shotgun mikes are long, thin tubes that attach to either your camcorder or a microphone boom. They record crisp, focused sound from a distance.

The different mikes also have a variety of other features, including different pickup elements, pickup patterns, connectors and cables.

Well briefly cover each feature to get you familiar.

Pickup Types
The heart of every microphone is the pickup element, the tiny device that converts the sound waves to electricity. You may hear people refer to a microphone by the pickup it uses. Pickups come in three basic types: dynamic, condenser and pressure zone or PZM.

The most common is a dynamic pickup element, also called a moving coil. In this type of mike, sound waves cause a diaphragm inside the pickup to flex back and forth further causing an attached coil to move along the path of a stationary magnet. This motion induces an electrical energy in the coil. Variations in this electrical energy represent the changing sound waves.

Dynamic mikes sound good, cost relatively little money and survive even the roughest handling. They also dont need batteries or other power sources to work.

They have one drawback: they aren’t very sensitive. Because they’re based on an essentially mechanical system, dynamic pickups need strong sound waves to generate good quality signals.

When a dynamic mike gets too far away, the sound quickly gets hollow, dull and tinny. For that reason, dynamic mikes work best in situations where you can get in close.

Condenser pickups use an electrical signal to increase the mike’s sensitivity. Much more delicate than dynamic elements, condensers require gentler handling. They can, however, record crisp, clear sound from a greater distance than a dynamic pickup.

Because they use an electrically charged system, condenser-based mikes need a power source, usually a battery.

Pressure zone pickups, also called PZMs, work differently. They have a tiny mike element suspended a few millimeters above a hard surface. The mike responds to sound waves reflecting off the surface. They can record exceptionally clear sound in an entire room without the echo and ambient noise problems that plague other mikes.

Ribbon pickups, while common in music studios, rarely see use in video. They record exceptionally clean sound, but are even more susceptible to damage than a condenser. That makes them less than desirable candidates for videos often rugged environments.

If you dont know whether a particular mike uses a dynamic or condenser pickup, heres an easy test: check for a battery. With a battery, its a condenser. However, it may also be a condenser even if it has no battery. Phantom power electret condensers take their power from a mixer input and have no batteries. If it has a battery, at least you can be pretty sure it is not a dynamic.

Pickup Patterns
Pickup types arent the only way people refer to microphones. You might hear someone calling for a particular mike by its pickup pattern.

The pickup pattern determines how selectively a mike will "hear" sounds in the outside world. Patterns come in two main groups: omnidirectional and unidirectional.

Omnidirectional mikes, also called omni’s, have a 360o pickup pattern meaning they will pick up sounds equally from any direction. They will also react equally to sounds reflecting off walls, doors, windows and other things in the scene.

Many camcorders use omni mikes. Although the camera mike may at times point away from you, if it’s an omni it will record your voice at the same volume.

Omni mikes dont cost much to make, and hence dont cost as much as other designs.

A mike with a unidirectional pattern, also called a cardioid, responds to sound coming from only one direction. It will hear more of the sound in front of it, and less of the sound behind it. You can aim a unidirectional mike at a sound source to highlight it.

As a rule, unidirectional mikes cost more than omnis. However, they can make a difference when you need to isolate the sound of someones voice amidst heavy ambient or background noise.

The hypercardioid or superdirectional pattern goes a step beyond the unidirectional. It narrows the focus of the unidirectional pattern to a smaller, more sensitive area. The design lets you stand up to three times as far from a subject and still record good sound. You can also aim a hypercardioid mike more precisely than a standard unidirectional mike.

Performance this good doesnt come cheap. Mikes with hypercardioid pickups are among the most expensive.

Some mikes have bi-directional or stereo pickup patterns. These work best for recording live music in stereo, or in other situations where you need to record sound coming from both sides of the mike.

Staying Balanced
The signal from a microphone wont help your video unless it gets to the mike input on your camcorder. You can use either a cable that stretches from the mike to the camera, or a wireless transmitter/receiver link to get the signal on tape.

Cables come in two types: balanced and unbalanced. The word "balance" in the name doesnt refer to the physical weight of the cable. Instead, the term refers to how the signal travels down a cable from the mike to the camera.

Inside an unbalanced cable, one wire carries the electrical signal, and a metallic shield carries a ground signal.

Some unbalanced lines generate noise when they rest near a power cord, get stepped on or rub against other mike cables. Balanced cables solve noise problems by adding wire inside the cable that carries a signal to cancel noise and hum. Balanced cables sound quieter and better than unbalanced ones, and thats why pros use them.

Most consumer electronics stores keep only unbalanced cables on their shelves, because nearly all consumer audio and video products have unbalanced inputs and outputs.

Many of the good microphones youll want to use for video, however, have balanced outputs. What does that mean for you? One word: adapters.

To make a balanced mike work with your camcorder, you’ll need an adapter that converts a balanced cable to unbalanced.

If you decide to use balanced cables, heres a very important tip: make sure to put the adapter on the cable at the camera end, not the mike end. By putting the adapter on just before the camera input, the signal stays pampered in the balanced line until it enters the camera. That reduces the chance for hum and other noise to ruin your soundtracks.

You can also get a wireless transmitter and receiver to use with your microphone. These systems let you record sound without worrying about a mike cable.

If a wireless system intrigues you, be sure to read the sidebar, "Going Wireless," included in this article.

Connecting Your Mike
Not every cable or wireless system will plug directly into your camcorder’s mike jack. You need the right connectors to complete the circuit.

Balanced cables use three-pin XLR connectors, because the cable itself has three conductors.

Unbalanced cables have only two conductors, so a phone plug works fine. Phone plugs come in either standard 1/4-inch size, or the mini 1/8-inch size.

Most camcorders have 1/8-inch mini plugs for mike inputs, although a few prosumer models have standard 1/4-inch phone plugs.

Make sure you either get mike cables that match your cameras input, or adapters to make them fit.

Mikes for Tight Budgets
Now that weve hit the features, its time to cover some mikes that might fit your productions and your budget.

If youre shopping with a limited amount of cash and you need a handheld mike, look for a dynamic, unidirectional model. Check out Azdens DX-431 ($30) or Audio-Technicas ATR30 ($60).

If you need crisp sound from interviews and other up-close voice recordings, go with a lavalier mike. A few examples: Simas LapelMike ($30), Audio-Technicas ATR35s ($40) and Nadys VLM-770 ($45), all omnidirectional condensers.

If you like the convenience of a camera-mounted mike, try a zoom or shotgun model for clearer sound. Some choices: Nadys VCM-100 ($65) and Sima’s ZoomMike ($50).

If you need to record a group sitting around a table, say a company meeting or discussion, try Radio Shacks PZM mike ($60), model number 33-1090.

If youd like to record in stereo, try Nadys SBM-500 ($50), which works handheld, attached to your camera or on a mike stand.

Although a wireless mike can rid you of cable tangles and snarls, you probably wont find a versatile, reliable one in the budget price range. Radio Shacks model #32-1226 ($70) qualifies, but operates in the same band as walkie-talkies, radio-controlled cars and other consumer remote control devices. Performance may not live up to your expectations.

Midrange Priced Mikes
If you need sound quality a notch above the budget mikes, expect to spend a few more bucks. Good sound doesnt come cheap.

You can find a good mike in the midrange category with either a traditional cable or a wireless transmitter and receiver system. Your projects should tell you whether to get a mike with a cable or without.

For handheld models, a unidirectional mike will keep out background noise better than an omni. Some models to try: Audio-Technicas ATR55 ($100), Shures VP64 ($135) or Electro-Voices N/D 257B ($180).

For live studio talk shows that need a mobile handheld mike, check out Nadys 151 VR ($200) or 351 VR ($300).

If you record interviews where your subjects dont move around much, a cabled lav mike delivers the best sound. Check out AKGs D-109 ($150).

If the subjects move around while they talk, consider a wireless lav system. Some choices: Nadys 151 VR ($200) and 351 VR ($300), Azdens WLX-Pro ($225) and Audio-Technicas Pro-88W with either an omni or unidirectional lav mic ($232). All of these are condensers, and need separate batteries for both transmitter and receiver. They also operate on the VHF band for better sound quality.

Zoom or shotgun mikes work well when you dont have the time or the extra mikes to give every person in a scene their own mike. Azdens ECZ-990 ($100) and Audio-Technica’s ATR55 ($100) are examples.

For stereo recording, check out Canon’s ZM100 ($220), with both stereo and superdirectional patterns.

Top Dollar Mikes
If sound quality is critical and price is not, shop some of the professional microphone lines for models that record sound suitable for film and broadcast use.

For traditional handheld mikes that require cables, try Shures SM58-CN ($215) or Electro-Voices RE15 ($480).

If you need a professional-quality cabled lav mike, your choices include Electro-Voices RE98 ($376) and CO100 ($386).

If you want wireless technology good enough for the pros, you need UHF transmitters and receivers with diversity (see sidebar). Systems vary in price depending on whether or not you want handheld or lavalier, diversity or not. Prices start around $500; Nadys 551 VR costs $850.

A number of companies also sell systems with prices stretching as high as $3000 for one package. Thats far beyond what most consumer videomakers can afford.

If youre one of those videomakers who needs first-class performance, call or write the manufacturers for specific information on different models. Prices and packages will vary depending on what you need.

Dont take the models weve suggested as the only choices available. Manufacturers often have a wide range of products to suit a broad user base. The best advice: start here and keep looking until you find one you like.

Once youve found it, practice using it. Experiment with different placements and positions to find where the mike sounds best.

Your projects will improve the most if you use the mike on as many as shoots as possible. Once youre comfortable with using an external mike, youll find its one of the easiest ways to make even simple projects much more enjoyable for your audience.

Where Common Mikes Work Best

  • HANDHELD: Best for either man-on-the-street or live studio interviews where you can get right up to the persons mouth. Also good for general music recording. The drawback: you often see the mike in the shot. If youre shooting as a one-man band, save your arm and get a stand to hold the mike for you.

  • LAVALIER: The ideal choice for recording human speech. Nothing beats a lavalier for getting crisp, clean sound of a persons voice without being obvious in a shot. It can also work as a backup omni mike if the camera or handheld mike breaks down.

  • SHOTGUN: Great for interviews and general shooting situations when you cant get any closer to the subject than where you put the camera. With a boom, a zoom or shotgun mike, you can record good sound from theatrical or dramatic scenes. This saves you the hassle of miking every person on stage. This type also works well as a backup mike when other systems break down or dont get adequate sound.

  • WIRELESS: Arguably the most convenient and versatile mike setup for any situation. If you record anyone or anything that moves, consider wireless. It gets cleaner results with less hassle than following with a shotgun or handheld mike. Hosts and interviewees can move around without worrying about cables or connectors. Air or car traffic, cellular or cordless phones and other radio problems can hurt performance, as can unusual or crowded surroundings.


Going Wireless
No matter how carefully you plan a location shoot or how carefully you lay out where to put the gear, you always end up hiding, untangling and recoiling mike cables. Not to mention having to disconnect and connect your subjects to cables every time they want to leave the set.

When someone tells you a wireless mike system can rid you of all these hassles, its no surprise that your interest piques.

Its a fact. Wireless systems do eliminate much of the hassle associated with cables. But you should know exactly how to shop for wireless systems so you get one that doesnt botch your soundtracks as it spares you a little cable wrangling.

With a wireless system, you attach the microphone to a small transmitter; a small receiver attached to the camera picks up the signal from the transmitter and routes it to your camcorders mike input.

Wireless systems can broadcast signals on any of three different bands. The higher the frequency band, the higher the price and the better the performance.

The range around 49MHz is the lowest. VHF sits above this range, and is most common for good consumer mikes. Pro mikes use the higher UHF band for the best sound.

The specific frequency a mike uses for broadcast is also important. Some models have only one frequency, which you select when you buy the mike. Others can switch between as many as four different frequencies.

Why worry about multiple frequencies? Because if you use more than one wireless mike on a shoot, or if youre taping an event alongside a number of other videomakers, all mikes must be on separate frequencies or you may not hear sound from them.

How far apart can the mike and receiver be? It depends on the system, as well as the terrain and conditions. Most work within 100 to 200 feet, although some advertise "line-of-sight" use beyond 500 feet. Under normal conditions, indoors or out, a mike should work acceptably at 100 feet from the camera.

To improve sound quality, some models include a feature called diversity. A diversity system puts two receivers in one box, and gives a separate antenna to each. The system constantly monitors signal strength from both receivers and switches back and forth to the stronger signal. The switching is silent and doesnt disturb or interrupt your program. The result: cleaner, more reliable sound quality.

If you choose wireless, always carry fresh batteries on every shoot. Some systems eat up batteries notoriously fast.

A tip about reliability and backups: while professional wireless systems often work with any standard XLR mike, consumer models may have a specific mike hard-wired to the transmitter. That mike is the only one you can use with that transmitter.

In a pro system, if the transmitter breaks or you run out of battery power, you can plug the mike into a cable and keep recording. You dont have that luxury with consumer systems, so be sure to bring a backup mike and cable in case the wireless doesnt work.


The Videomaker Editors are dedicated to bringing you the information you need to produce and share better video.

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