Pros:

• A USB microphone connects to a computer through a standard USB port.
• You can record directly into a computer without the need for additional equipment.
• They’re relatively affordable.

Cons:

• USB MICS ARE NOT GOOD ENOUGH FOR VOICE-OVER. Their ADC technology is too sensitive to ambient noise and electronic noise.
• While it's possible for a computer to recognize more than one USB microphone at time, setting it up can be potentially difficult.
• Most USB microphones are dependent on a computer for operation, so they’re not as versatile as regular microphones.
• If your ultimate goal is to record the best-sounding voice-over possible, you’re going to need to use a different kind of microphone.

Pros:

• Dynamic Broadcast Microphones are more forgiving when it comes to plosive sounds (the “P” sounds that pop and the “S” sounds that hiss), and thus are a little easier to work with, compared to Large Diaphragm Condenser mics.
• They don’t require phantom power to operate (phantom power is explained later in the guide).

Cons:

• DYNAMIC BROADCAST MICS ARE NOT IDEAL FOR VOICE-OVER.Even though they have a nice warm sound, Dynamic Broadcast Mics lack a little detail in the upper mids and high frequencies.
• Additional equipment is required to use them with a computer.

Pros:

• CONDENSER MICS ARE GREAT FOR VOICE-OVER.
• Large diaphragm condenser mics have a very detailed response, with lively sounding upper frequencies.
• If you control room ambience and use proper recording technique, you can capture the highest quality of sound using one of these mics.

Cons:

• The ultra-sensitive capsule in a Large Diaphragm Condenser mic is more susceptible to capturing unwanted plosive and vibration noises.
• Additional equipment is required to use them with a computer.
• They require phantom power to operate.

What is phantom power?

Some mics require a little flow of electricity in order to operate. This little flow of electricity is called “phantom power.” It’s a feature that’s commonly found on computer audio interfaces. Using phantom power isn’t complicated, and you shouldn’t be intimidated by it.

The best way to connect a professional 3-pin XLR microphone to a computer is to use an audio interface. An audio interface is an external piece of hardware that connects to a computer via USB, FireWire, PCI or Expresscard. Many audio interfaces feature dedicated XLR microphone inputs, headphone outputs and other jacks and controls that come in handy for recording voice-overs. You can learn everything you need to know about computer-audio interfaces in this B&H Buyer’s Guide.

Plugging a microphone directly into a computer audio interface will get you a clean, flat sound--and depending on the interface it can allow you to control gain, sensitivity, input, mixing, and more. Because audio interfaces contain a large, dedicated Analogue-to-Digital Converter (ADC), they have a much better noise floor (Signal-to-Noise Ratio) than the tiny ADC's in USB mics (which have a noticeable hum from electronic noise alone, not to mention heat, ambient noise, and more). When it comes to ADC's, the bigger the better, becasue the internal circuitry (which is sensitive to vibrations), is less prone to unwanted electronic noise if it has more mass and therefore more resistance to changes in momentum caused by magnetic disturbances from parasitic capacitances and inductive couplings in internal circuitry. Moral of the story: an XLR with an audio interface easily outperforms a USB mic with a small ADC integrated curcuit.

However if your goal is to create the best possible quality for broadcast voice-overs, you can improve your sound even more by plugging your mic into “outboard gear” before you connect it to a computer audio interface. Outboard gear is external hardware that enhances the overall sound of a microphone. USB microphones cannot be used with outboard gear. This increases the price for beginners, so outboard gear is not totally necessary until you're serious about a voice acting career.

Voice-over microphones are very detailed sounding and do an outstanding job of bringing out the rich textures and nuances of a voice. However, one downside to using such sensitive microphones is that they also pick up unpleasant-sounding sibilant and plosive sounds. Words with the letter “P” sometimes make a popping sound that can overwhelm the microphone capsule. Words with the letter “S” sometimes create a short, yet strident, harsh hissing sound. The easiest and most effective way to eliminate these problems is to avoid recording them in the first place by using a pop filter.

A pop filter is a small screen that attaches to a microphone stand with a clamp. A short gooseneck runs from the clamp to the screen, so you can position it a couple inches in front of the microphone capsule. The screen diffuses rushing air created by these problematic plosive and sibilant sounds. The screens themselves can be made of a metal, or a foam-like fabric which is often mistaken for pantyhose.

If your voice talent is going to be sitting at a desk or at a table during the recordings, then your best choice may be a desk stand or a studio arm. A desk stand is a compact, table-top version of a microphone stand. A studio arm is a balanced, articulated boom arm that can mount to a desk or a table with either a removable clamp or a permanent stud. Studio arms make it easy to quickly reposition a microphone without creating noise.

If your voice talent prefers to stand while they work, there are numerous microphone floor stands available. Taller floor stands with boom arms are recommended. The boom arm will give you more options for positioning the microphone.

A shockmount is a small suspension system that prevents a microphone from picking up unwanted handling, vibration and rumbling noises. It mounts on the end of a microphone stand and holds the mic. A shockmount suspends a microphone with rubber or elastic bands (or utilizes similar kinds of suspension systems), which eliminates most of the vibration and handling noise the mic would otherwise pick up. The kind of shockmount you need depends entirely on what kind of microphone you’re using. Sometimes shockmounts come as included accessories when you purchase a microphone.

Professional recording studios usually have a specially designed vocal booth that enables the engineers to record neutral sounding vocal tracks that are free of room ambience. Hard surfaces (such as desktops, walls, floors, and ceilings) tend to reflect sound and send it bouncing around a room. Rooms with long corridors and odd shapes only compound the problem. You probably don’t notice sounds bouncing around your room in normal everyday life, but when a sensitive microphone is used to record a voice, and that voice is taken out of the context of the room and placed over video footage, suddenly the ambience of the room sticks out like a distracting, sore thumb.

The best way to control room ambience is to use sound-absorption material and baffling while you record. One of the most cost-effective ways to cut down on room ambience is to hang a duvet around your recording space. A general rule of thumb for beginners who want to be careful with money is to utilize things you already have to improve your recording.  Some people even record in their walk-in closets. The video below goes over some potentail ways you use materials you already own to create a vocal booth.

Another way to cut down on room ambience is to place acoustic paneling in key points around the room in which you’re recording. There are different-sized acoustic panel kits available (some of which include bass traps and adhesives) for various-sized rooms. These products are designed solely to control room ambiance. They won’t make your studio any more soundproof than it already is, nor will they prevent exterior noise from leaking into your workspace.

It’s necessary to wear headphones when recording voice-overs because you don’t want the microphone to pick up sound from your speakers. It’s important to record in a quiet room, and headphones make it possible to listen to the video playback without speakers. If you record voice-overs with speakers on, the sound quality will decrease dramatically, and you run the risk of creating a feedback loop and damaging your hearing and equipment.