Mar 30, 2008

Microphone Technique

It may seem like second nature to some to speak into a microphone. Others may look at the microphone with the same look you'd give a high-tension wire lying on the ground. The fact of the matter is that good microphone technique is important to produce a good podcast. Different mics have different pickup characteristics and different sensitivities, so you must use proper technique to get the best out of your mic.

The basic requirement is that the microphone be in front of the sound source, as close as possible, but not so close that the microphone distorts or picks up any noise, particularly from troublesome consonants such as the letters "p" and "b." These letters are known as plosives and can be quite problematic, because the burst of air that comes out of your mouth when you pronounce them can cause the microphone to "pop." This is audible as a loud pop or a "thunk" in your recording. You may be able to get rid of this noise later on using signal processing, but try to avoid them in the first place.

Plosives are created by letting out a big burst of air from your mouth. The pop occurs because the tiny diaphragm inside the microphone is overloaded. To avoid this, you can use a pop screen, which is a bit of foam or sheer material designed to break up the burst of air. Pop screens must be acoustically transparent, meaning that they should not muffle or distort the sound at all. Many handheld microphones have a pop screen built in, as shown in Figure 1. For other mics, you can buy foam pop screens that fit over the microphone or a pop shield that is placed in front of a microphone. All of these are very effective at reducing the incidence of microphone pops.

Figure 1: A pop screen

Tip In a pinch, you can create your own pop shield by stretching a piece of pantyhose over a coat hanger and placing it in front of your microphone.

Handheld mics
Handheld mics are generally dynamic, directional mics, which means that they are resistant to handling noise, and tend to pick up in one direction. Directional mics must be pointed at the source they're recording. That may seem obvious, but novices sometimes forget they're holding the mic. Their hand will drop to their side, completely oblivious to the microphone. For this reason, handheld mics are often better left to seasoned professionals.

Clip-on mics
Clip-on mics, also known as lavalier mics, are a great option for most podcasting applications. They're small and unobtrusive, so people often forget they're even wearing them. (This can be somewhat embarrassing when a guest or on-air talent attempts to walk away with the microphone still attached.) Clip-on mics come in both directional and omni pickup patterns. For interviewing applications, use omni-directional mics, because they provide better pickup when the person speaking turns his head from side to side. If you're using directional mics, the level can drop dramatically when the talent turns away from the mic. For that reason, microphone placement is important when using clip-on mics.

The placement of a clip-on mic is dependent on the pickup pattern of the microphone, the clothing the talent is wearing, and the placement of guests, as shown in Figure 2. If two people are facing each other, for example sitting across from one another at a table, the mics should ideally be placed centrally, about six inches below the speaker's chin. If two people are sitting side by side, the mics should be placed so that when they are talking the mics will be in the best possible position to pick up the signal.

Figure 2: Clip-on mic placement depends on the situation.

Studio mics
If you have the luxury of a studio setup for your podcasts, you can use high-quality studio microphones. These mics can be used only in studio settings because they are so sensitive. They are very susceptible to handling noise and therefore impractical for handheld or non-studio applications.

Studio mics are placed on mic stands and often in special suspension mounts that make them less sensitive to vibration. The mic should be positioned so that it points at the talent's mouth. Usually, you want to have the mic a little high and pointed slightly downward towards the user's mouth, as opposed to below them and pointing up. This helps prevent pops, because the burst of air tends to be aimed downward.

Many, but not all, studio mics are condenser mics. In fact, two of the most popular radio mics, the Shure SM-7 and the Electrovoice RE-20, are dynamic mics. Both of these mics are treasured because of their lack of proximity effect and their resistance to pops.

Mar 26, 2008

Bit depth and sampling rates

Bit depth and sampling rates
Bit depth and sampling rate are the two things that determine the fidelity of a digital audio file. You may have seen pairs of numbers rattled off in equipment brochures such as 16/44.1, or 24/96. The first number generally refers to the bit depth, the second to the sample rate.

In the previous section, we talked about taking measurements of an analog input at specific intervals. This is the sample rate. As the sample rate increases, the digital representation more closely resembles the analog original. You must choose a sample rate that is high enough to give you the fidelity you require.

Bit depth is the other variable in the fidelity equation. Bit depth refers to the number of bits used to represent the measurement of the analog voltage. For example, you could represent the distance to the nearest street corner as a block, 50 yards, 143 feet, or 1,717 inches. As you increase the accuracy of your measurement, you need more digits to represent the number. The same is true for our digital samples of our audio input.

In the binary world, each bit you add doubles the range of numbers you can represent. Looked at in another way, each bit you shave off your bit depth cuts your accuracy in half. If we use eight bits, we can have up to 256 different values. With 16 bits, we get more than 65,000 possible values, and 24 bits provides more than 16 million values. So how much accuracy do we need?

Choosing your digitization settings
Ideally, you want to record using the highest sample rate possible, and use the largest bit depth you can. The problem is that using high sample rates and large bit depths creates larger files. Increasing the bit depth from 16 to 24 bits increases the file size by 50 percent, and increasing the sample rate from 44.1KHz to 96KHz more than doubles the file size. Even though storage is relatively cheap and getting cheaper all the time, there are some practical limits to how much fidelity you really need, especially given that podcasts are encoded using lossy codecs such as MP3 that compromise the fidelity. A better master provides a higher podcast quality, so how much fidelity do you really need?

Compact discs use 16 bits and a 44.1 KHz sample rate. Most people consider this sufficient to capture the full range of audio that the human ear is capable of hearing (though many audio engineers would disagree). This is probably what you should use for your master recordings. Although many recording devices and audio editing platforms now offer higher sample rates and bit depths, it's debatable whether the extra quality justifies the increase in storage requirements. You'll just end up using lots more storage space for your archived masters.

If you're producing your podcasts to an extremely high standard, consider using 24/96 (24 bits/96KHz sample rate). This "future-proofs" your masters and will impress all your audio engineering buddies. For most folks, however, the standard 16/44.1 setting will more than suffice.

Tip If you're producing a video podcast, Digital Video (DV) audio is sampled at 48KHz, or sometimes even at 32KHz. These sampling rates were chosen when digital video standards were developed. They're different from the 44.1KHz audio sampling rate, because the sampling rate for audio predates them and was chosen due to technological restrictions at the time. This is fine; the key is not to resample the audio to 44.1KHz (or any other sampling rate). Re-sampling introduces artifacts and degrades the quality of the original audio.

Mar 22, 2008

Setting up a gain structure: A step-by-step example

It's time to set up your gain structure to produce high quality audio. The procedure is simple, starting with the first piece of audio equipment and working your way through the signal chain until you get to the final destination, your computer.

For the purposes of this example, we'll assume that you're using a microphone and a mixing desk, a USB audio interface, and recording straight to your hard drive. Your audio setup may differ slightly, but you should be able to follow these steps regardless:

1. Connect your microphone to your mixing desk, your mixing desk to your USB interface, and your USB interface to your computer. You should be using balanced cables whenever possible, because they provide a solid connection point and are highly noise-resistant. Turn on your mixing desk. If you're using a condenser microphone, be sure to turn phantom power on (or you won't hear a thing).

Tip : Be sure to turn on phantom power after you've connected all your microphones. Some microphones may be damaged if you plug them in with the phantom power already turned on.

2. Make sure you're monitoring only the microphone channel. Some mixing desks have "Solo" buttons to accomplish this; if your mixing desk doesn't have a solo button, then make sure all the other channels are turned down.

3. First, set the input level of the microphone. Do this by adjusting the input level (or trim) knob at the top of the mixing desk channel your microphone is plugged into, as shown in Figure 1. Speak into your microphone, and adjust the input level. The Mackie Onyx 1220 uses a peak meter, so adjust until it is peaking at -6dB to -3dB. A few peaks over zero are okay.

Figure 1: Setting the input level on a Mackie Onyx 1220 mixing desk Courtesy Mackie Designs, Ltd.

4. To set the output level of the mixing desk, take the channel out of solo mode if your desk has a solo button. The meters on the mixing desk will now show the level of all channels combined. Turn your microphone channel up to 0dB (on some desks this is marked "U" for unity gain).

5. Mixing desks allow you to move things from side to side in the mix. This is known as panning, and is controlled by the pan knob on your mixer. Each channel has a separate pan control. Make sure your microphone is in the center of your mix. Check the pan setting to make sure it's right in the middle. Sometimes conversations between two people can sound more intimate if the two speakers are panned slightly to the left and right, but most of the time — and especially when setting up your gain structure — all microphones should be right in the middle of your mix.

Tip When recording an interview between two people, it's tempting to pan one person hard left and the other hard right. That may sound cool at first, but it isn't. It ends up sounding like ping-pong, where the voices are jumping from one speaker to the other. If your listeners are using headphones, you'll drive them absolutely crazy. A little separation is fine, but don't go overboard. And remember that if you're using stereo for separation, you're going to have to encode in stereo, which requires a higher bit rate to sound good.

6. Adjust the final output of your mixing desk by adjusting the master volume. This is generally on the lower left of the mixing desk, below the meters. You should set the output meters to -6dB to -3dB, leaving a bit of headroom for the unexpected.

7. Next it's time to move on to the USB audio interface. Depending on the make and model, you'll have some sort of meters and some sort of input adjustment. On some models, the metering can be fairly rudimentary. Adjust to keep your level consistent with the output level of the mixing desk. If you don't have full meters on your USB interface, you can use your recording software to check your input level. Open your audio editing software. You may need to put it in record mode to get to the level meters. Make sure your level is in the -10dB to -6dB range, and remember that anything over zero will distort!

Note Some USB audio interfaces come with special software to adjust the input level. If so, use this software to set your levels. After you've set the level via the software application, the level is automatically set for your audio editing software.

Congratulations. You've just set up your gain structure. Each piece of equipment is operating in its optimal range, so you should be producing a high-quality, noise-free audio signal. The best part about setting up a gain structure is that after you've set it, you shouldn't have to worry about it anymore. You can make small adjustments if necessary using the channel adjustments or the master volume output of your mixing desk.

Tip If you're connecting a number of different audio sources to your mixing desk, label the channels so you know what is coming in on the channels. Some mixing desks have an area to do this, known as a channel strip. If your desk doesn't have a channel strip, you can always create one by stretching a strip of masking tape below the channel faders (or knobs). Then you can write on the masking tape. Believe me, when you're grabbing for a fader in the middle of a podcast recording, knowing which fader is the right one is critical.

If you have more microphones or more equipment that you want to use during your podcast, you should set the input level for each channel just as we did for the microphone channel in the previous example. You can adjust the relative volume for each channel as needed using the channel level adjustments, so that all your inputs are mixed together at the right levels. Now that your levels have been set, you need to learn a little about digital audio.

Caution Make sure you always plug microphones into mic inputs and line level equipment such as CD players and iPod headphone outputs into line level inputs. Most inputs are clearly labeled as one or the other or have a switch that determines the expected input level. If you plug a microphone into a line level input, you won't get enough gain. Conversely, a line level output distorts a microphone input. Just because a cable fits doesn't mean it's the right input!

Understanding digital audio
At some point, your audio is going to have to be digitized on the way to becoming a podcast. Digitizing is the process of converting an analog audio input into a digital audio file. Whether you're recording directly to your hard drive or you're using a digital recording device, you have to choose which digitization settings to use.

To fully understand what is involved in digitization, understanding how digital audio files are created is important. Figure 6.3 illustrates an audio signal. The audio signal starts off as a continuously changing voltage. This voltage is created by the vibrations of the diaphragm inside a microphone and is what eventually causes the cones inside a speaker to vibrate and reproduce the original sound.

Figure 2: A sound wave and how it is digitized using samples

To store this as a digital audio file, we take measurements of the wave at specific intervals. These measurements are known as samples. In Figure 2, each section of the wave has different numbers of samples under it. The number and accuracy of these samples determine how accurate the digital version of our audio file is and therefore the fidelity of the digital version to the original.

Mar 19, 2008

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.

Mar 14, 2008

Equipping a Studio on Any Budget

Okay, we've talked about equipment until we're blue in the face. It's time for you to go out and spend some money. We know you want to. We also know you probably want recommendations. We're not going to tell you exactly what to buy, but we'll make some general recommendations, based on a total estimated budget. Remember that audio equipment doesn't go out of style as quickly as cell phones do; if you buy the good stuff, chances are it will last you a lifetime.

The following suggestions below don't include some of the extras that you're going to need with every setup, such as microphone cables, stands, acoustic treatment for your recording environment, and so on. The amount of extra equipment you need is dependent on the equipment you buy and the scale of your podcast. Whatever you do, be sure to buy good cables, and buy a few spares, just in case.

Cheapskate ($0)
Hey, no one is saying you have to spend money. You can do a lot with a little. In fact, you may want to do a few test runs with no investment to make sure you're going to enjoy podcasting and to see where the painful points are before you spend any money. If that's the case, you can make due with the following:

- The crappy mic you found in the empty office next door

- The built-in soundcard on your laptop

- Windows Sound Recorder or Mac Sound Edit 16

- The plastic speakers that come with most desktop computers

- Audacity audio-editing software

Just plug it all in and go. When you realize the quality could be better and it's time to spend some money, step up to the next level.

Novice (<$250)
The most important purchase you can make is a good microphone. The new USB mics offer good quality, or you can buy a standard microphone (so you can use it with portable recording units or for other applications) and an audio interface. The cheaper audio interfaces have a maximum of two mic inputs, so you'll be somewhat limited, but two mic inputs may be all that you'll ever need. You'll also need a decent set of headphones to monitor with, so your shopping list looks something like this:

- A USB mic (Samson CO1U, Blue Snowball), or a decent dynamic mic (Shure SM58, EV635) and a USB or FireWire audio interface (M-Audio Mobile Pre, PreSonus FireBox)

- A decent set of headphones (Sony, AKG, Sennheiser)

- Audacity audio-editing software

With this modest investment, you can create a great-quality podcast easily. The microphone is going to increase your quality exponentially, and Audacity should take care of most of your editing and processing needs.

Enthusiast (~$600)
After you've got the bug, you'll probably want to buy some more equipment to make your life a little easier and to broaden the possibilities for your podcast. A small mixing desk is a must, and a telephone hybrid probably will come in handy. You also should buy a good set of monitors so you can hear the improved quality you'll be producing. You also may consider upgrading your audioediting software.

- A Shure SM58 or EV 635 mic

- A USB mixing desk (Yamaha, Alesis, Mackie)

- A telephone hybrid (JK Audio)

- A decent set of monitors (Tapco, M-Audio)

- Sound Forge LE, Peak editing software

Professional ($1,000 +)
After the sponsorship money starts rolling in, you can really get serious. It's time to spring for a true broadcast-quality microphone and a top-notch digital telephone hybrid. While you're at it, you may want to upgrade your mixing desk, and heck, you may as well grab the flagship audioediting software.

- A top-notch mic (Shure SM7, EV RE20, Neumann TLM49)

- A Telos One digital telephone hybrid

- A Mackie Onyx FireWire mixing desk

- High-quality monitors (Mackie, Genelec, JBL)

- Sound Forge, Audition, or Peak Pro editing software

At this point, you should be in audio nirvana. You've got a fabulous mic, a telephone hybrid, a great desk to mix it all with, and fabulous audio-editing software. There is nothing you can't do. The world awaits the glorious quality of your podcast.

Mar 12, 2008

Understanding the Recording Environment

Understanding the Recording Environment
So far we've spent the entirety ogling all kinds of cool audio equipment that will produce higher-quality podcasts. However, there's a very important element that we haven't even touched on: your recording environment. Any audio engineer will tell you that the environment is a huge contributing factor to the quality of your production. All recording studios are specially built to provide an environment where things sound good.

Building recording studios is very skilled work, because recording studios must be capable of recording anything that walks through the door, from audio books to rock bands. For podcasting, we're trying to create a neutral environment, so that the sound of the guest's voices cut through. The last thing you want to hear is the sound of the room you're recording in.

A classic example is the sound of bathroom tile. We all sing in the shower because the highly reflective tile surfaces around us reflect our voices back to us, bathing us in a sea of reverb. Everyone knows exactly what a bathroom sounds like. You can't record in there, because folks will know you're recording in the bathroom!

The same goes for small closets or even small offices. Our ears detect the size of rooms by the reflections we hear. Think about that the next time you're stuck on a boring conference call. You can tell in a split second how big the room is on the other side of the call, and the sound quality is almost always horrible. That's because offices with whiteboards, windows, and big wooden tables have lots of reflective surfaces that fill the room with reflected sound, which is what makes it hard to listen to for long periods of time.

What you really want is a room that is nice and quiet, one that doesn't have too many reflective surfaces. If your room doesn't sound good to start off with, it's not too hard to make it sound much better with some sound treatment.

Sound treatment
If you've ever been inside a radio station, you know that the studios are nice and quiet. If you look around, you'll notice that the walls are treated so that they absorb sound. They have to be built this way, because there are microphones all over the place and all they want to broadcast is people's voices — not the sound of the room. Because you probably don't have the money to build a studio from scratch, you can do the next best thing: Use acoustic panels to treat your walls.

Acoustic panels are large pieces of foam or some other sound-absorbing material (see Figure 1). These panels are attached to walls and ceilings to reduce the amount of sound that is reflected. This makes the room sound neutral, because no sounds are reflected to give our ears a sense of space. Consequently, the sound going into your microphone is just your pristine voice, and nothing else.

Figure 1: Acoustic tiles can turn a terrible sounding room into a great recording environment.

You can do other things to improve your environment, some of which are just common sense. For example, if you're recording a conversation around a large table, place a tablecloth on the table. Not only does the tablecloth damp down any reflections from the tabletop, but it also absorbs noises like people putting coffee mugs down, tapping pens, and doing lots of other distracting things. If your space has windows, consider buying curtains and closing them when you're recording. Anything you can do to minimize large reflective surfaces will help.

Studio layouts
If you're going to create a dedicated space for your podcast production, take some time to think about how you're going to use it. You should consider different studio configurations, depending on how you're going to produce your programming. The simplest is a single operator studio.

Single operator
If you're going to be the producer, engineer, and star of your own podcast (of course), then you're probably going to do everything in the same room. You need enough space to accommodate all the equipment you've accumulated after reading this post and enough space to accommodate however many guests you plan on having. Remember that your guests probably will want some table space of their own to put their coffee, their laptop, and whatever else they've brought along. Make sure they have access to power, because they'll want to recharge all their gadgets during the podcast. (Make sure they turn off their cell phones.)

Be sure to have your equipment mounted in a special rack, or on a separate table, to protect it from spilled drinks. Equipment racks often have the added benefit of being on wheels, so when your production is finished, you can roll the equipment out of the way until the next time.

Another thing to consider is the noise generated by your computer. If you're using a modern desktop machine with a high-powered processor, the noise made by the cooling fans may be picked up by your mics, particularly if you're using condenser mics. It's best to minimize this as much as you can. One good approach is to replace the standard fans and power supplies with low-noise versions available from vendors such as PC Power & Cooling ( If you don't feel like shelling out the extra money for quiet fans, you can reduce the amount of noise picked up by your mics by moving the offending machine as far away as possible. You also can attenuate the noise with acoustic foam or small baffles.

Talent + engineer
If you're fortunate enough to have some help producing your podcast, you may want to consider setting up a studio where the talent (meaning your guests and you, the interviewer) is in a separate room from the equipment. This accomplishes a few things. First, the audio engineer works without worrying about keeping absolutely quiet. Second, audio equipment can be somewhat intimidating to some people, so doing the interview in another room can sometimes make for a more relaxed, natural interview.

Mar 10, 2008

Using Telephone Tools

Using Telephone Tools
Many podcasts include call-in guests. To get the audio from the phone into your computer, you need a telephone hybrid. Hybrids are specially designed to accomplish this with the least amount of noise possible. This is a little harder than it seems, because telephone lines are often very noisy. Telephone hybrids cost anywhere from $10 to $1,000. The $10 versions available at your local electronics store sound horrible and should be avoided.

Hybrids fall into two basic categories: analog and digital. The analog versions use basic circuitry to extract the audio from the phone line. The digital versions use sophisticated signal processing to clean up the audio signal and separate the caller from the interviewer. If you plan on doing lots of interviews over the phone, you should seriously consider buying a high-quality digital phone hybrid, as expensive as they may be. If phone calls are not a regular feature of your podcast, you can spend a little less, but you should still buy a good-quality hybrid, like the ones shown in Figure 1. If you make your phone calls on a mobile phone, you can buy hybrids that can be inserted between the cell phone and the earpiece.

Figure 1: Telephone hybrids: The JK Audio Inline Patch, Telos One digital hybrid

A number of technologies have been developed in the last few years that allow telephone calls to be made over the Internet instead of via a Plain Old Telephone System (POTS) line. One of the most popular is Skype. Skype is a P2P telephony system, which means there isn't a huge centralized server that's managing all the resources. It's all decentralized and distributed, and even better, it's free. Many people are taking advantage of this new service to make long-distance calls to friends in foreign countries.

Of course, this is all fine and good, but how can you record your Skype conversation? You can't use the fancy telephone hybrids discussed in the preceding section, because you're not using a phone! Instead, you use specialized software designed to record audio directly from your software audio mixer. A number of applications are designed to do this, with more appearing all the time. Here are a few examples:

Hot Recorder (Windows): This application works with a number of different Internet telephony applications and even includes voicemail for Google Talk and Skype. It records into a proprietary .ELP format but converts this file to .WAV, .OGG, or .MP3.

Pamela Professional (Windows): This application includes a number of features including voicemail and support for "pamcasting" (podcasting).

Audio Hijack (Mac): This application records virtually any sound off your computer. It includes built-in timers for scheduled recording.


Gizmo is another Internet telephony program. It works pretty much the same as Skype, but it has a couple of cool added features. First, it is SIP enabled, which means that you can talk to people on other VoIP networks, not just Gizmo users. It also is integrated with Google Talk, which is another up and coming Internet telephony application. Best of all, Gizmo includes recording functionality. Just push the record button, and presto — instant podcast.

Mar 8, 2008

Recording on an iPod?

Yes, in fact you can record on your iPod. However, there are a few drawbacks. If you're using an older iPod model (non-video model), they can record only 16-bit, 8 KHz files, which is basically telephone quality. This is fine for memos to yourself, but it's not broadcast quality. The newer models can record broadcast quality, but be careful because these high quality files are uncompressed .WAV files. WAV files require a lot of hard drive space and consequently burn through battery power because the hard drive constantly spins during the recording.

To use your iPod for recording, you need to purchase either Griffin's iTalk or the Belkin Universal Mic Adapter. (Note that these devices are not compatible with all iPods.) They're cheap, and they're ultra-portable, so it's not the worst idea to carry one around so that you can grab an unexpected interview when you're traveling.

Of course, if you're feeling brave, some very clever people have figured a way around the crippled recording capabilities of the older iPods. However, this isn't just a special sequence of keys you have to press. If you want to record pristine 16-bit, 44.1 KHz audio, you have to install Linux on your iPod.

Yes, you read that right. Some very clever people have figured out how to run Linux on an iPod, and it includes the ability to record. Needless to say, this is not something your authors can heartily recommend. In fact, forget you even read it here. We don't want any e-mails from people who break their iPods.

Mar 6, 2008

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.

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.

Mar 4, 2008

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.

Mar 3, 2008

Podcast: Signal processors

Audio production techniques that you can use to optimize your podcast. These can be done using either hardware or software. Software is convenient because you can use presets or create customized settings for your podcast that you can use every week. Even more useful is the ability to "undo." However, sometimes hardware processing is handy. You can't beat the feel of real knobs, and who wouldn't like more flashing lights in his studio? A couple of hardware processors are shown in Figure 1.

Figure 1: Signal processing units: Presonus Comp16, EQ3B

Equalization (EQ) units

Equalization is a process whereby tone is altered by boosting (turning up) or attenuating (turning down) certain frequencies. The bass and treble knobs on your car stereo apply EQ. Most mixing desks include simple EQ, but you may want finer control of your tone at times. In this case, you'd buy an external EQ unit. You also can use EQ units to fight feedback problems (refer to the "Feedback: What It Is and How to Avoid It" sidebar).

Audio compressors help control your audio levels. Compressors turn audio levels down when they cross a certain threshold. They're incredibly useful because they protect your equipment from distortion due to abrupt level changes — for example, if one of your guests suddenly starts yelling. You can place a compressor between your mixing desk and your audio interface as a protective measure or compress your input channels individually.

Effects units
Effects units enable you to add special effects to your podcast, like echo and reverb. Effects are often used in music production to make the band sound like they're playing in a large hall or club. For most podcast material, this simply isn't appropriate. If you listen to the radio carefully, you'll notice that special effects are used sparingly, and even then only on the "bumpers" (the show announcements) or on advertisements.

Audio interfaces
At some point, your analog audio signal must make the transition between the analog and digital worlds. This can be done at various points in your signal chain. Once upon a time, the only way to get sound into your computer was via a soundcard, but that is no longer the case. Audio interfaces can connect via USB and FireWire, mixing desks come with built-in audio interfaces, and you can even buy USB mics.

Virtually every computer sold these days comes with some sort of audio interface. Usually, there's a headphone and/or speaker output, a microphone input, and a line level input if you're lucky. The problem is that these soundcards are usually built with really cheap components and are low quality. Microphone inputs on soundcards tend to be very noisy. They're very vulnerable to electrical interference (of which there's plenty inside a computer). In general, you should avoid using the mic input on a soundcard.

This doesn't mean that you can't produce a podcast using whatever soundcard you're stuck with. Hey, the idea is to get podcasting as quickly as possible, right? If you must use the soundcard that came with your hand-me-down computer, and if you must use the microphone input, go right ahead. Just remember that when you decide it's time to improve the audio quality, the soundcard is probably the place to start.

Plenty of good soundcards are available today. You should look for a soundcard that uses professional 1/4″ or XLR connectors, because they're far more reliable and resistant to noise. Many soundcards these days come with a breakout box that you can place on your desk or a shelf, so you don't have to crawl behind your computer every time you want to plug something in. Check out the example in Figure 2.

Figure 3: Soundcard with breakout box: M-Audio Delta 44

External audio interfaces
Another way to get digital audio into your computer is to use an external audio interface. This type of stand-alone unit connects to your computer via USB or FireWire. Until recently, only a few of these were available, but now you have lots to choose from. One nice thing is that most of these units come bundled with tons of great recording tools, so if you don't have an audio editor, you might consider picking up an external audio interface just to get the software!

Like soundcards, external audio interfaces come in many shapes and sizes and have different features, such as number of inputs and so on, like the ones shown in Figure 5.14. One thing to consider is power; most of these units run off the power supplied by the USB or FireWire bus, but to get power on a FireWire cable, you need the larger six-pin cable. Some laptops come equipped only with the smaller four-pin FireWire input, so you'll have to supply external power if you're using a FireWire interface. For the ultimate in portability, you may want to go with a USB version.

Figure 4: External audio interface: M-Audio Mobile Pre (USB), PreSonus Firebox (FireWire).

Recording devices
You have a number of options for recording. The most obvious is to record directly to your hard drive. However, this may not be an option if you're recording on location, or if you don't want to lug your computer around with you everywhere you go. Of course, these days, people bring their laptops with them everywhere, but if you don't want to do that, this section discusses other options for recording your podcast.

You can record in many different formats. Some, like the cassette, have been around for ages, but are still entirely useful. Others, like tapeless recording, are relatively new. Tapeless recording is of particular interest to podcasters, because you can transfer the files from your recorder to the computer digitally and much faster than real-time transfers.

Cassettes were initially developed as a dictation format and never designed to be high quality. But they caught on like wildfire, so manufacturers improved the tape quality and the electronics, and they even added noise reduction systems like Dolby. If you have a decent cassette deck lying around, you can use it, but be sure to buy high-quality chrome cassette tapes and set your record levels high so you don't hear tape hiss. Of course, you can always use studio trickery later on to get rid of (or at least reduce) tape hiss.

Digital Audio Tape, or DAT, appeared in the mid-1980s as a high-quality studio format, but found its way into the consumer market. Although it has largely disappeared in the past ten years, plenty of serviceable DAT machines are still out there, and they're very high quality.

Sony has been trying to convince the world that MiniDisc is a great format, but few people have listened. MiniDisc just never seems to go away, no matter how poorly it sells. This is partly due to the fact that MiniDisc units use ATRAC compression on the audio signal, which is acceptable for spoken word content, but not really acceptable for recording music masters. As a portable podcast recorder, a MiniDisc unit can be quite useful, especially because you can find them on craigslist for under $50 and MiniDisc blank discs are cheap.

MP3 recorders
A handful of MP3 players include record functionality. Most of these units do not have external mic inputs. A few have a line input that you can record from, but this means having some sort of mixing desk for the mic pre-amps and feeding the line level output into your portable MP3 player — not exactly a compact setup. Of course, you can use the built-in mic these units tend to include. If you're in a quiet location, it's probably fine. But don't expect broadcast quality.

New tapeless options
If you want the latest and greatest, look no further. Several manufacturers have released high-quality tapeless recording options in the last year. You can see some examples in Figure 5.15. These units record to compact Flash memory cards, which you can pop out and put into a USB card reader connected to your computer, or you can connect the unit to your computer using a USB cable. This allows you to transfer files much faster than real-time transfers; the transfer time depends on the type of file you recorded.

Figure 5: The M-Audio MicroTrack 24/96, a portable recorder that records to Flash cards or microdrives

These tapeless units generally offer uncompressed recording in the WAV format, as well as MP3 recording at a variety of bit rates. Most come with built-in microphones, but for highest quality you'll want to use your own mics, of course. Some units offer XLR connectors, some 1/4″ or 1/8″. As of the writing, models are available from four manufacturers, but we're sure you'll have many more choices by the time you read this.

Mar 2, 2008

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

Mar 1, 2008

Podcast: : Other types of microphones

All the microphones described previously will serve you well, but they're not the only mics suitable for podcasting. A number of specialized mics might be better suited for your podcast, depending on your situation.

Clip-on (Lavalier) mics
Clip-on mics are common in television news broadcast, because they're small and unobtrusive. This also can be an advantage in podcasting, particularly if your guest has little or no experience talking into a mic. Many folks can be intimidated by large broadcast mics. Clip-on mics are great because the guest can forget about the mic, relax, and give a good interview. Two great lavalier mics are shown in Figure 1.

Figure 1: Clip-on (lavalier) mics: ElectroVoice RE90L, Audio Technica AT803B

Audio Production Tools 5

Headset mics
Headset mics can be ideal for some applications. You often see them on tradeshow floors so that the speakers can use their hands and not worry about holding a microphone. The other reason they're useful is that the microphone is very close to the speaker's mouth, so very little background noise is picked up. Some headphones include a built-in microphone, which is handy in situations where you need to wear headphones and want the convenience of a headset mic.

Many, many headsets today are sold by numerous companies to work with your cell phone, your laptop, your PDA, and who knows what else. Many of these headsets are very cheaply made. If you want to go the headset route, stick to the professional models. Most microphone manufacturers make a headset model. Two good headset mics are shown in Figure 2.

Figure 2: Headset mics: Audio Technica ATM75CW, Shure WBH53B

Wireless mics
Wireless microphone technology has been around much longer than wireless connectivity has. A number of different standards and transmission methods exist. Wireless mic setups involve one or more wireless mics and receiver units that convert the wireless signal back into analog audio. Wireless can be pretty slick, but it can be pricey. Setups start at around $500 per single mic and go up from there. The other problem is that wireless systems are prone to interference. Also, wireless microphones run on batteries, and as we all know, batteries always run out right in the middle of the most important part of the interview, right?

PZM / boundary mics

Pressure zone microphones (PZM mics) are designed to be placed on a large flat surface. They're ideal for conference room tables or podiums. They're kind of cool because they don't look like mics, so folks tend to ignore them. An example of a PZM mic is shown in Figure 3. They're not going to give you the same performance as a quality handheld or clip-on mic, simply because they tend to be further from the people speaking. However, they can be useful in situations where it's not practical to put a microphone in front of every single speaker.

Figure 3: PZM mic: Crown PZM 185

USB mics
One of the most interesting recent developments has been the arrival of the USB microphone. USB mics have built-in digital audio conversion, so instead of connecting them to a mixing desk, you plug them directly into your workstation. All mixing and signal processing of your podcast must be done in your audio-editing software, because you aren't using external hardware. You also are limited by the number of USB ports your workstation has. However, if you're looking for the ultimate in portability, a USB mic may be ideal. A number of USB mics are available, including the ones shown in Figure 4.

Figure 4: USB mics: Samson CO1U, Blue Microphones Snowball, Sound Professionals USB Mic-1

If you're looking for the ultimate in portability, Sound Professionals makes a USB mic the size and shape of a small flash drive, which offers amazing quality for the money. While it doesn't offer the quality of a dedicated microphone placed in front of each person talking, it's an indispensable tool for the laptop warrior.