Once upon a time audio engineers dreamed of a digital microphone. With the advent of the USB mic that dream is now a reality. This type of mic requires no mixing board or interface box. You simply plug it into the USB port of your computer and voila! The mic appears as an audio input device on your computer.
The first mics were primitive–just a mic and a USB cable. Gain was controlled in the sound panel of your computer. And because the digital output had to be processed by the computer, there was a noticeable delay when you monitored the output.
But USB mics have matured and the latest generations have made them a good choice for voice over home studios. Here are six tips on what to look for in a USB microphone.
1. You Need a Quality Mic
I often say “shop at Guitar Center, not at Office Depot”. This means buy a real mic–not a headset or gaming mic. You want at least a “pro-sumer” mic. You don’t need to spend a fortune, but for around $150 or more you can get a mic that will produce broadcast quality performances.
2. Choose a Large Diaphragm Condenser Mic
There are two popular types of microphones: dynamic and condenser. “Dynamic” sounds like it should be a good thing. But a dynamic mic produces a signal with a coil of wire. The mass of this coil causes a restriction in frequency range. And the coil can pick electric signals from motors, fluorescent lights and other electrical equipment.
A condenser mic uses a very thin capacitor to generate the signal. It has very little mass so it can pick up high frequencies and very quickly changing sounds called “transients”. A larger diaphragm is better for capturing lower resonances.
3. Look for a 20-20,000 hz Frequency Range
Human hearing range is 20-20,000hz so your mic should capture all those frequencies. Some mics (dynamic mics for example) are limited to 12,000 or 15,000 hz. This will cause a “muddy” sounding recording that will lack the sparkle and “air” that a full spectrum mic can capture.
4. Zero Latency Headphone Monitoring.
Wow, that’s a mouthful. Early USB mics required you to listen to your performance through software monitoring. That meant your voice had to travel into the computer, get processed into your recording software, and then be “echoed” back to the computer headphone jack.
This caused a quarter second delay to the sound in your headphones… I call it the “Elvis in the stairway” effect. This delay made it impossible to listen to yourself in headphones while you recorded.
Newer USB mics have a headphone jack on the mic with a volume control built in. Just plug in your headphones and hear your voice with zero delay.
Also you can use these mics as an output device. You can play back your recording and hear the playback in your headphones.
5. Consider a 24 Bit Mic
Most USB mics are designed around an analog-to-digital chip set that produced a 16 bit recording. The latest mics use a 24 bit chip set. I’ve never been asked for a 24 bit recording but as blue ray discs and high definition video becomes more popular future producers will start asking for this.
24 bits give you much more “headroom” and a quieter recording. 16 bit gives you a dynamic range of about 96 decibels. 24 bit produces recordings give you a range of 144 decibels. That’s like standing next to 10 jet planes at full power.
At this time there are only two 24 bit mics: the MXL USB 009 and the Blue Yeti Pro. Both of these condenser mics also have headphones jacks and wide frequency range.
6. Check Out the Chart
Here’s the voice over home recording studio article with lots of information on what you need to record at home. It has a chart of USB mics to give you an overview of brands and models available.
Have Studio Will Travel
With a laptop computer and your trusty USB mic you’ve got an entire voice over studio. And it’s portable so you can take it where ever you go. USB mics have simplified the home studio while providing high quality recording. So use these tips to select the USB mic that’s right for your needs.