There are a few simple steps you can take to improve the quality of your voice recording.

A disclaimer:
I am not now, nor have I ever been a member of the A.V. Club, I am not an audio geek, and I do not hunt swap meets for vinyl records because they sound “warmer”. I have however recorded myself in a variety of embarrassingly unprofessional ways, and would like to share my findings. I will focus on the recording of the spoken word only.  This article is progressive. Each step below will improve your final product, but you should only choose the steps that are practical for your situation.

You will get the most from this post if you wear headphones.

Step 1: Check your Gain

Make sure your microphone’s “gain” (sound input) is set relatively “hot” (high sound input). It is always possible to “attenuate” your recording (turn down the volume), but “amplifying” your recording (turning up the volume) will increase system and background noise.

Under my Mac’s sound settings, I have set the “input” level at about 4/5th. You can record “hotter” than this as long as your recording doesn’t start to distort. When actively recording, if the input meter moves into red, your gain is set too high, and there will be distortion in your final product.

Sound Input Settings on Mac

Using these settings, here is what the internal microphone on my computer sounds like.

All samples will use the following text:
“I am testing my microphone to verify that my voice is detected. If my microphone is properly connected and turned on, the recording meter will show movement”.

Step 2: Set Your Sample Rate & Bit Depth

I am not even going to try to explain sample rate and bit depth. For more information on this subject read the Wikipedia entry on signal processing.

When I record myself teaching, I like to set the sampling rate to at least 44100 Hz and the bit depth to 16-bit (or 24-bit). These are the settings for CD quality sound. I often use the free program Audacity to record audio, as it is easy to set these quality levels in its preference panel. Audacity is free, open-sourced, and works on both the MAC and PC platforms.

Sample Rate Audacity

22,050 Hz Sample Rate

At this lower sample rate, notice that my voice is a little tinny and metallic sounding

44100 Hz Sample Rate

The metallic quality is no longer present.

Step 3: Buy a Decent USB Microphone

Let’s face it, the microphones that come pre-installed in our computers and laptops are only good for skyping. The most important step you can take in improving sound quality is to buy a microphone.

There are a lot of different microphone types, and it is beyond the scope of this article to discuss them all. For lecture recording, I prefer to use a USB condenser microphone, specifically the Audio-Technica AT2020 ($130 on amazon). This microphone is easy to step-up, relatively cheap, and requires no further equipment (I.e. no audio mixers, cables, and the like). This microphone is designed for podcasters, so don’t plan on using it to record anything other than your voice. USB microphones send digital audio directly to your computer via a USB cable. As such, the sound quality is high and the system noise is low.

Using the settings above, here is what the AT2020 microphone sounds like.

AT2020

With the AT2020, I would also suggest getting a floor mic stand as the included desktop stand is unstable and weak. I often unconsciously shake my leg when recording so the desktop stand is particularly problematic.  The “On Stage Stands MS7701” tripod boom stand is functional, unobtrusive, cheap ($25), and compatible with most microphones (including the AT2020).

Step 4: Position

When speaking try to face the microphone “on axis” (straight on). In the case of the AT2020, a blue light indicates where the front of the microphone is. Secondly, keep your sound source (your mouth) about 6 inches from the microphone.

In this example, I recorded the first half of the text at 1 inch and the second half at the suggested 6 inches.

micdistance
Using your hand as a measuring tool is a common technique for making sure you are not too close to your microphone.

Step 5: Pop Filter

Pop filters reduce popping sounds produced by the pronunciation of “plosive” consonants like “P” and “B”. To produce plosive sounds, humans abruptly stop the flow of air and then release this air in a mini-blast. When this mini-blast hits the recording element a popping sound is produced. Additionally, pop filters protect your microphone from potentially corrosive saliva particles. Most pop filters attach directly to the stand and should be placed about 2 inches in front of the microphone.

In this example, I recorded the word “pop” with and without a pop filter.
Stedman Pop Filter
I use a Stedman PS101 Metal Pop Filter.

Step 6: Reflection Filter

The room I record in has plaster walls, hardwood floors and confined spaces. In fact, there is a wall about 3 feet in front of my microphone. These conditions produce an amazing amount of reflected sound. For the most committed, the last recommended piece of equipment is a reflection filter. The reflection filter reduces the amount of ambient sound picked back up by the microphone.

Here is the same text with a reflection filter.

To make this point clearer, here are the last two word (“show movement”) without and then with a reflection screen. Notice that the second clip is “drier”.

reflection filter

I use an Auray RF-5P-B reflection filter. It is a little pricey but will work with the microphone and stand suggested above.


Wrapping it  up

In this last recording, you can hear each of the above clips back to back.

The first clip uses the internal computer mic, the second uses an external USB mic, the third adds a pop filter, and the last adds the reflection filter.