Multi-track Audio Production

When you begin to create podcasts, you'll probably use a simple stereo audio editing program. As your productions become more professional, you may be tempted to move up to a multi-track audio program. Multi-track systems offer a number of benefits, the most important one being the ability to separate the elements of your podcast onto separate tracks. This, in turn, enables you to work on the tracks individually, applying tailored effects such as EQ and compression to each track on an individual basis.

Things to consider
Now that you're graduating to the world of multi-track recording, the first thing to do is label them appropriately so you know what is on which track. Sure, you say, I'm always going to put my mic on track #1, the guest on #2, and the music on track #3. Well, what happens when you add a telephone hybrid? What happens if you're sick and your buddy agrees to finish off one of your podcast productions for you? Believe me, it may seem pedantic, but labeling your tracks will save you lots of headaches in the long run.

Next, to take full advantage of a multi-track recording setup, you'll need an audio interface capable of multiple outputs and a mixing desk with multiple outputs. Each track can be assigned to a particular input, as shown in Figure 1. If you have only a stereo audio interface, you can still record to separate tracks, provided that you pan the two separate channels hard left and hard right on the mixing desk, and then record the left channel on one track and the right channel on another.


Figure 1: Sony Vegas multi-track software

After you have your audio recorded, bear in mind that the overall level will be cumulative. You have to be careful when you mix all your tracks together so that you don't end up with too much level. This can often happen if everyone talks or laughs at once. Suddenly, you have not one track but two or three, all feeding your master mix. This is why you'll want to think about using a compressor on each track or across your master mix if your software allows it.

Multi-track audio software is different in this manner, in that the effects you apply are not performed on the file. Instead, they are applied in real time as you play back the audio. In addition to being able to apply effects to each track, you can also apply effects to the master mix. In this situation, you could apply light compression to each of the input tracks and then a limiting compression to the master mix to make sure you never go into distortion.

Multi-track templates
If your podcast follows a particular format, for example if you use the same intro and outro music for each show, you can save time by creating a multi-track template that you can drop (or record) your audio into each week. Instead of having to worry about finding your theme music and worrying about levels, you just place the theme music on a separate track and then record the rest of your podcast on separate tracks. When you record using multi-track software, tracks that are not in record mode simply play back, so you'll hear the theme music in your headphones, and as it fades out, you jump in with your introduction.

Basic Audio Production

Now that you've spent time drooling over the latest and greatest audio gear, and invested some of your hard-earned cash in decent equipment, you need to figure out how to hook it all up and produce professional sounding podcasts. The great thing about working with audio is that for a minimal investment, you should be able to produce your podcast to a very high standard. The powerful technological leaps we've seen in the world of computers have also brought great advances (and price drops) in the world of home recording. What once required thousands of dollars worth of equipment now costs hundreds, or less.

We will start off showing you how to connect your equipment to get the best sound, and then talks about some general recording techniques. Audio production may seem daunting at first, but by setting up some simple procedures and sticking to them, you'll find it to be pretty simple, and more important, lots of fun.

After that, we cover editing, where much of the power of audio production actually lies. Good editing can transform your podcast from mundane to professional. The techniques described are all standard operating procedure in radio, television, and recoding studios around the world. Though we can't hope to turn you into an audio engineer in a few short pages, we can at least point you in the right direction. Let's start by setting up your equipment — the right way.

Setting Up Your Equipment
Different kinds of equipment you need to produce your podcast to a high standard. Ideally, you took the plunge and bought some equipment to fit your budget and the scale of your production. Now it's time to unpack everything and connect everything together. This is actually a critical step in podcast production. If you set up your equipment incorrectly, you'll leave yourself vulnerable to noise, interference, and distortion, which will compromise the sound quality of the final production. If set up correctly, your hardware will have you on the road to creating broadcast-quality programming. To understand why this step is important, you have to understand the concept of gain.

Setting your levels
Gain, also known as level, is the measure of the power of your audio signal. When using analog audio equipment, such as microphones and mixing desks, the signal is a continuously varying voltage. The higher the voltage is, the higher the gain and the louder the audio. All audio equipment is designed to work within a certain known range of voltages. To obtain the best possible quality out of your audio equipment, without adding any noise or distortion, you want to work within the optimal range for that piece of equipment, known as its dynamic range.

Dynamic range
The dynamic range of a piece of audio equipment is the difference between the loudest sound it can handle without distortion and the internal noise floor of the equipment. For example, when you turn a portable radio up too loud, you'll hear the sound crackle and buzz; that's distortion. You've just exceeded the dynamic range of the radio. The noise floor lies at the other extreme of the spectrum.

All audio equipment produces some amount of noise; there's no such thing as a perfectly quiet piece of equipment. That's because they're imperfect by definition. Every piece of audio equipment has all kinds of electronic components, each one adding a minute amount of noise, which taken in total is the noise floor. You can hear this noise — just turn your stereo up really loud while you're not playing anything. You'll hear a hissing and possibly a buzzing noise. This is the system noise that is being amplified. If you were actually playing a CD, you wouldn't hear this noise, because the music would be much louder than the noise.

More expensive equipment uses better components, which produce less noise. Consequently better equipment has a greater dynamic range. Cheaper equipment, well, you get the idea. This is the argument for investing in decent audio production equipment. If you produce audio with no audible noise, your podcast sounds much better. Noise is a dead giveaway that an amateur is behind the controls. Another giveaway is distortion. After your signal distorts, you can't remove the distortion. It can't be edited out of the signal, and it compromises the quality of your podcast.

Dynamic range is measured in decibels (dB). The human ear is capable of perceiving up to 120-130dB of dynamic range, before the pain threshold kicks in. We can hear a faucet dripping down the hall in the middle of the night, and endure hours in front of our favorite rock band. Our ears are extremely sensitive, which is not necessarily the case with the equipment and/or transmission methods used to produce audio.

Different audio transmission methods have different dynamic ranges. For example, compact discs have about 96dB of potential dynamic range, whereas FM radio has only about 70dB of dynamic range and AM radio has only about 48dB of dynamic range. This is because of the noise inherent in each system. If you think about it for a second, the quality differences between these systems is obvious. The larger the dynamic range is, the higher the quality of the audio signal and the less apparent any noise is.

Using meters to monitor levels
To control your levels, you need to keep an eye on your meters. Virtually every piece of audio equipment comes with some type of meter to indicate the level of the signal. Meters fall into three main categories: VU meters, LED Peak meters, and software VU/Peak meters, shown in Figure 1.


Figure 1: A software VU/Peak meter Courtesy Sony Sound Forge

The first is VU or Volume Unit meters, which are common on older equipment (and new equipment going for that hip retro look). The needle indicates the overall power of the signal, represented as an average. They're very good for comparing the volume or power of a signal, but not good at registering quick peaks. VU meters usually have two scales, one that runs from 0 percent to 100 percent, and another that has zero where the 100 percent mark is, with negative numbers below 100 percent and positive numbers above 100 percent.

The next type of meter is the LED (Light Emitting Diode) Peak meter. LED meters are very fast, so they are generally used to indicate the peak values of the audio signal. LED meters generally have a single scale, measured in dB, running from approximately -40dB, up through zero, and on to +10 or +20dB.

Note Decibels are a relative measure of power. The decibels used to measure the +20dB measurement on a meter aren't the same as the 120dB pain threshold. One is a measure of sound pressure, while the other is a measure of voltage. It can get kind of confusing

Finally, we have the software meter. Software meters can operate as VU or LED meters, and sometimes as both concurrently. In the image on the right of Figure 1, the meter indicates both VU level (the bulk of the display) and peak level (indicated by the thin line hovering above the VU level). The critical difference between analog meters and software meters is that analog meters have headroom, which means that the signal is allowed to go above zero, and digital meters have no headroom: Go above 0dB, and you'll hear awful square-wave distortion, which is very unpleasant. Digital meters usually include some sort of clip or peak light that indicates when you have peaks above zero. These must be avoided at all costs.

The point of all this is that you need to be careful when setting up your equipment Set your input level too low, and you're liable to hear some of the internal noise of your equipment. Set your level too high, and you'll get distortion. What you want to do is set a level that is high enough so that you don't hear equipment noise and conservative enough that you don't ever get distortion. It's a fairly broad range, so spend the time to learn how to set levels correctly. The result will be a much higher quality podcast.

Setting levels
When setting a level with a VU meter, be careful because VU meters don't register peaks. Those peaks may be loud enough to exceed the equipment's dynamic range and therefore cause distortion. It's best to set your levels between -10dB and -6dB on a VU meter. This leaves quite a bit of headroom for transient peaks, and any unexpected jumps in level. When you're setting levels with a peak meter, you can be a bit more aggressive, because you can see pretty much exactly where your peaks are. You should set your level so that the indicated level is in the -6dB to -3dB range. These settings should get you a good, clean, loud signal, with very little perceivable noise. If your levels occasionally peak above zero, don't worry; most audio equipment has sufficient headroom to handle momentary peaks without distortion.

Setting levels in the digital domain is a whole different matter. Any signal above 0dB causes distortion, because 0dB is considered an absolute maximum. As long as the signal remains above 0dB, you keep getting the same maximum value. The result is a sound wave with the top squared off, which sounds horrible. This is known as square-wave distortion.

You must be conservative when setting levels on digital equipment. Digital meters are almost always peak meters for precisely this reason. When setting your digital levels, you should target -10dB to -6dB. This should leave you plenty of headroom. It's better to be a little conservative and maximize your level later on using signal processing rather than set it too high and end up with distortion.

Additional tools (podcast)

If you think your shopping list is getting a little too long, take a deep breath. You're going to need these odds and ends to produce your podcast.

Cables
Believe it or not, it's actually important to buy good-quality cables. Good cables are more noise resistant and last longer. In particular, if you're going to be doing lots of location work, you'll find that the constant plugging and unplugging of cables, as well as packing and unpacking them, can take a toll. Make sure to pay a little bit extra to buy good cables.

You should be using shielded, balanced cables wherever possible. Shielded cables include a wrapping of foil or wire mesh built in to the cable to reject outside magnetic interference. Balanced cables use an ingenious phase-cancellation method to make them even more noise resistant. Balanced cables are easy to recognize because they use three conductors in the cable: a positive, a negative, and a ground. The plugs on the end are either XLR or TRS, as shown in Figure 1.


Figure 1: Balanced plugs: Male XLR, female XLR, TRS

If your cable runs are very short, you don't have to use balanced cables. It's just a good idea, and believe me, you'll be glad you did.

Pop screens
Certain letters, known as plosives, involve a large burst of air when they are pronounced, in particular the letters "p" and "b." This burst of air can result in a loud pop in your recording, which is very hard to remove, even with sophisticated signal processing. The simplest way to avoid pops is to use a pop screen. Pop screens come in two basic versions: a foam covering for your microphone or a disc that you place in front of your microphone that has sheer material stretched across it. Either one works, so figure out which works best with your mic and buy it.

Mic stands, clips, suspension mounts
Mic stands are important if you don't want to spend the entire podcast holding a microphone. You'll definitely need a mic stand if you're using a condenser mic, because they're far too sensitive to be handheld. Mic stands come in floor standing models, tabletop models, and spring-loaded desk-mount models. The spring-loaded models are particularly useful because they let you swing the mic out of the way after you're done recording.

Of course, you'll need a clip to hold your microphone to the mic stand. Most mics come with mic clips that are made specifically to hold them. For condenser mics, you should consider buying a suspension mount. Suspension mounts support the mic in a web of elastic bands or springs so they are floating independently of the mic stand, which makes them even more noise resistant.

Audio editing software (Podcast)

Audio-editing software

To get the most out of your podcast, you're going to need audio-editing software. Audio-editing software gives you the power to turn your raw podcast shows into things of beauty. Plenty of audio editors exist, from freeware all the way to specialized recording platforms for recording music. All are capable of basic editing operations such as cut and paste, as well as more advanced forms of signal optimization.

This list of some of the most common full-featured stereo audio-editing programs is by no means meant to be a definitive list:

- Audacity (Windows, Mac, Linux): Audacity is a free, open-source audio editor that runs on just about every platform. What's not to love?

- Peak (Mac): Berkeley Integrated Audio Software's flagship stereo audio editor comes in a number of versions at different price points.

- Sound Forge (Windows): Now a part of the Sony family, Sound Forge comes in a number of different versions at different price points.

- Audition (Windows): Formerly CoolEdit, Audition is now Adobe's flagship audio editor, offering all the quality you'd expect from an Adobe product.

Creating a podcast involves more than just audio editing. Some audio-editing programs include additional podcast production tools, such as built-in file transfer (FTP) and Real Simple Syndication (RSS) support. Not all of the programs listed here include sophisticated audio processing. They're meant to be simple, easy-to-use tools that get the job done as quickly as possible.

- GarageBand (Mac): Originally intended as a very simple multi-track audio-editing program, GarageBand now includes just about everything you need to make a podcast. One problem, though, is that it does not export MP3 files; it only exports AAC encoded files, which is fine for podcasts targeted at iPods, but not for other portable music players.

- ePodcast Producer (Windows): This editor includes many handy podcast production features, including a teleprompter, sound effects management, and a built-in facility for recording Voice-over IP (VoIP) phone conversations such as Skype.

- Propaganda (Windows): This editor uses an interesting model where multiple clips are cued up to produce your podcast, much like a digital cartridge system used at radio stations.

- Podcast Station (Windows): This editor is similar to Propaganda in that you assemble your podcasts from lists of clips. Simple insert editing and unlimited undo make this a great platform for the podcaster who enjoys winging it. The Web site includes lots of tutorial videos to get you up and running quickly.

If you're planning on creating video podcasts, you should be aware that many video-editing software platforms also include audio editing and processing. Your decision on which audio-editing platform to buy will be based on the operating system you're working on, your familiarity with audio-editing software, and how much functionality you want in a single tool. You may want to create a few podcasts on a shoestring budget using open-source tools and see what works best for you before investing your hard-earned cash.

Podcast : Mixing Desks

Mixing desks, or mixers, provide centralized control of all your audio sources. Mixing desks combine multiple audio sources into a single master mix. Each source is plugged into a separate channel that offers individualized control. All adjustments can be done in real time; for example, you can play music during the intro to your podcast, bring the level of the music down, and then turn your microphone up. If a guest is speaking too loudly, you can turn his microphone down. (Or, if you're a domineering type like some television talk show hosts, you can "cut it" — turn it off completely.)

Another feature of most mixing desks is multiple outputs. Most have a headphones output, as well as a master output, a control room or monitoring output, and possibly others. This flexibility allows you to do a number of things. You can listen to, or monitor, your audio in a number of ways. You can connect a pair of speakers to your mixing desk or use headphones. You can connect a recording device to your mixing desk if you want to record your podcast on a device other than your workstation. Mixing desks provide you with the flexibility to do just about anything you want with your audio.

Mixing desks offer these features as well:

- Phantom power: Condenser mics require phantom power to operate.

- Level adjustment: You can adjust the level of each source.

- Equalization (EQ): You can adjust the tone of each input to optimize the sound.

- Stereo panning: You can move inputs from side to side in your stereo mix.

- Effects sends: You can add special effects to your mix such as echo and reverb.

If you're going to be doing any sort of live recording, you should buy a mixing desk. The flexibility it provides is invaluable. Another reason to consider buying a mixing desk is the microphone inputs (also known as mic pre's, short for microphone pre-amplifiers). Microphones produce a lowlevel signal that must be amplified considerably. Cheap mic inputs (like the ones included on most soundcards) add a significant amount of noise during the amplification process. Mixing desks have much higher quality mic inputs, so they produce much higher quality signals. In fact, mic input quality is usually the distinguishing factor of a mixing desk.

Mixing desks come in all shapes and sizes, from portable models that offer a few input channels, to broadcast consoles that require special stands. A desktop mixing desk is probably most appropriate for podcasting. Be sure to buy a mixing desk that has more inputs than you need; people tend to "grow into" their mixing desks. After you realize that you can leave everything connected, you'll find yourself connecting everything to your mixer.

One of the latest developments in mixing desk technology has been the addition of USB and FireWire outputs. These new outputs enable you to connect the mixing desk directly to your workstation, without having to use an external audio interface or a soundcard. These are incredibly handy, because you'll have one less piece of equipment to buy (or worry about). Many mixing desk manufacturers are coming out with USB and FireWire models. In general, the FireWire models are slightly more expensive, because they enable higher sampling rates and bit depths. A couple of models are illustrated in Figure 1.


Figure 1: Mixing desks: Mackie Onyx 1220 (FireWire), Yamaha MW10 (USB)

Monitoring (headphones and speakers)
When producing high-quality audio, you should know that what you're hearing is accurate. It's worth investing in a good pair of speakers, which are called monitors in the broadcast world. You'll also need a good set of headphones to be able to monitor while you're recording to avoid feedback (which is explained in the "Feedback: What It Is and How to Avoid It" sidebar).

Headphones can be either closed back or open back. Open back headphones tend to be lighter and more comfortable, but the design has a couple of potential shortcomings. First, outside noise can come in via the open back, so they're not good for noisy environments. Second, if the headphone volume is turned up too loud, the sound coming out of the back may be picked up by nearby microphones. This is known as bleed. It's usually not too much of a problem with spoken presentations, because headphone volume tends to be low and the bleed minimal. It can be a factor when recording live music, however, which tends to be monitored at much greater levels. Closed back headphones are best for noisy environments, because they allow less outside noise to reach your ear, and less headphone noise leaks out.

A number of specialized headphones are available. Most portable players come with in-ear headphones. In-ear headphones offer excellent isolation because they're so close to the ear drum; some are even custom molded to the ear canal. This is a double edged-sword, though. Anything that close to your ear drum has the potential to do lots of damage. Noise-canceling headphones use sophisticated circuitry to minimize ambient noise such as the whine of an airplane engine. Wireless headphones send the audio signal via a wireless technology such as Bluetooth or UHF. For critical listening, use a good pair of wired headphones. They're less susceptible to interference, and they don't have any fancy circuitry messing up your audio. A couple of standard broadcast headphone models are shown in Figure 2.


Figure 2: Broadcast headphones: Sony MDR-7506, AKG K240S

Although you can do all your podcast production with a good set of headphones, you'll also probably want to invest in a good set of monitors. Headphones can be fatiguing, and they have an exaggerated sense of stereo separation. You should always check your mixes on a set of monitors. Remember that a good portion of your audience will be listening at their desktop computers, so you should make sure their experience is going to be good. Granted, your audience may be listening on cheap plastic speakers that came with their "multimedia-enabled" computers. That's no excuse for you to produce using the same equipment. Producing your audio to the highest possible quality requires accurate monitoring.

Monitors are probably the most contentious piece of audio equipment you'll buy, because judging the quality of a pair of monitors is very subjective. You'll see all sorts of jargon tossed around on manufacturers' Web sites, along with frequency response diagrams and rave reviews from audio engineers. Generally, the more you spend, the more accurate the monitor. Also, because low frequencies are particularly difficult to reproduce accurately, more expensive monitors have better low frequency reproduction. Many desktop multimedia speaker systems use subwoofers to reproduce the low frequencies. These are fine, provided the subwoofer doesn't color the sound too much.

One thing you should definitely consider is whether the monitors are shielded. Shielded monitors are built so that they don't pick up interference from video monitors, which can be a problem. You also may want to buy active speakers, which have amplification built in, so they don't require a separate amplifier. Many professional monitor manufacturers exist, and each has a wide selection of monitors. A few examples are shown in Figure 3. Choose monitors that fit your budget and sound good to you.


Figure 3: Monitors: M-Audio StudioPro 3, Tapco S-5

Podcast: Audio Production Tools

Audio gear looks really cool and has lots of flashing lights and plenty of meters; the current trend of making audio gear look slightly retro adds to the effect. Audio gear is also relatively cheap. Although you can easily spend thousands of dollars on audio gear, you can get great audio quality out of budget home recording equipment, which has vastly improved in the last ten years. And most importantly, quality audio gear immediately improves the quality of your podcast.

Most podcasts are produced from the podcaster's home or office, so lets talks about the tools required for a basic podcasting studio. Some folks grab interviews on the go, so a section of this post is dedicated to portable recording. Many podcasts include remote guests who call in on either a traditional phone line or an online phone service such as Skype, so telephone tools are covered in detail.

In any recording situation, the environment is important to the final quality, so this covers things you can do to improve your recording environment. Finally, some suggested combinations of equipment are listed, so that you can make a shopping list for your audio gear.

Using Basic Production Tools
Many multimedia computers ship with microphones, speakers, and soundcards, but in general the quality of these bundled tools is not very high. That doesn't mean that you can't produce a podcast with whatever tools you have on hand. But if you want to produce to a high standard, you should invest accordingly. Your podcast quality is limited by the quality of your audio signal chain, and that starts with your microphone.

Microphones
The quality of your podcast, to a large extent, is dependent on the quality of your microphone. If you use a cheap plastic mic, your podcast sounds cheap and, well, plastic. Spend a hundred bucks, and you can compete with the best of them. But before you pull out your credit card, learn a little bit about how microphones work and which type of microphone is best for you.

Pickup patterns
Microphones have different pickup patterns, or directional response. Omnidirectional mics pick up sound from all directions equally. Directional mics pick up sound predominantly from a particular direction, and reject sound from other directions. Most mics are directional, with a particular pickup pattern. These are the most common pickup patterns:

Cardioid: Cardioid mics pick up predominantly what is in front of them, less of what is to the sides, and very little of what is behind them. The name derives from the heartshaped pickup pattern.

Supercardioid (or hypercardioid): These microphones exhibit an exaggerated cardioid pattern, with more rejection of sound from the sides and rear. Hypercardioid mics are commonly referred to as shotgun mics.

Figure 8 (bi-directional): Figure 8 mics pick up sound from the front and rear, but not from the sides.


Common microphone pickup patterns. Cardioid mics (left) are mostly sensitive to the front, with some sensitivity on the sides and very little to the rear. Supercardioid mics (center) are less sensitive to the sides than standard cardioid mics, but also have some sensitivity to the rear. Figure-8 microphones (right) are sensitive along a given axis and much less sensitive off-axis.

As you can see in figure above, mics have different pickup patterns, and more importantly, have a front and a back! It's pretty obvious which end you speak into with handheld mics, but it may not be so obvious with some higher-quality mics. For example, some mics have a switch to determine the pickup pattern. If you switch from a figure-8 to a cardioid, which side is the correct side to speak into? In most cases, the manufacturers put their logo on the "front" of the mic. If you're not sure, you can always try speaking into both sides of the mic. When it's set to cardioid, one side sounds much louder and brighter than the other side.

In most cases, a directional mic with some type of cardioid pickup pattern is the best choice. These mics can easily be pointed at the talent, and by design won't pick up much else. The one exception is with clip-on (or lavalier) mics. If you decide that clip-on mics are going to work best for your needs, you should buy omni versions. Even though they're omnidirectional, they really don't pick up anything other than who they're attached to. The advantage of the omnidirectinal pickup pattern is apparent when the person turns his head from side to side. With directional mics, this leads to a dramatic drop off in signal level. With an omnidirectional mic, the drop off is far less apparent.

Dynamic versus condenser mics
Most microphones fall into two basic categories, dynamic microphones and condenser microphones. Dynamic microphones have a diaphragm that is attached to a coil of wire, known as the voice coil. The voice coil is suspended between magnets. When the diaphragm vibrates in response to incoming sound, the magnets create a very small oscillating current in the voice coil by a process known as electromagnetic induction. This current is an electrical representation of the sound wave.

The diaphragms in condenser microphones consist of two plates coated with a conductive material such as gold. A voltage, known as phantom power, is placed across the plates to form a capacitor. (Historically, capacitors were called condensers, hence the name condenser mic.) When incoming sound causes the plates to vibrate, the distance between them varies, which varies the capacitance. This variation in capacitance is converted into an oscillating current, which is an electrical representation of the sound wave.

Condenser mics are much more sensitive than dynamic mics. This translates to higher frequency response and lower noise. However, the sensitivity comes at a price: Condenser mics are very sensitive to handling noise, and therefore cannot be held in your hand. They're always placed in microphone stands and sometimes in special suspension mounts. If you're in a controlled situation, you may want to take advantage of the higher quality that condenser mics offer. Some reasonably priced condenser mics are shown in Figure 2.


Figure 2: Condenser mics: Neumann TLM49, AKG C3000B, Audio Technica AT4033
Dynamic mics may not have quite the frequency response and dynamic range that condenser mics have, but that doesn't mean there aren't some fabulous dynamic mics. In fact, two dynamic mics are broadcast industry standards, the ElectroVoice RE20 and the Shure SM7B, shown in Figure 3. These mics are prized for their tone, and both are incredibly resistant to the proximity effect. Either of these would be ideal for your podcasting studio.


Figure 3: Studio dynamic mics: ElectroVoice RE20, Shure SM7B

If you're going to be working on location or outdoors, or you just don't want to be tied down to a chair in front of an expensive mic, you can buy a nice handheld mic. Handheld mics are dynamic mics by definition, because they must be resistant to handling noise. They're usually sturdy enough to survive being dropped, which, as any reporter can tell you, is important. You should always have a handheld mic or two, because they're very reasonably priced and can serve as backups in case of equipment troubles. Some great handheld mics are shown in Figure 4.


Figure 4:Handheld mics: Electrovoice 635A, the venerable Shure SM58