So you've decided to start up a podcast, or maybe you've been doing it for a while and have decided to improve your sound. Either way, it's time to look for some equipment. There's a an enormous amount of choice out there when it comes to sound gear, and almost as many opinions as to what's best for what. The purpose of this post is to clarify what's important for you, as a podcast producer, and what you should focus on in order to get a good balance of quality and price.
To simplify things, let's break the recording setup down into 3 general components: Microphone; Interface; and Peripheral (or miscellaneous) Gear.
The most important piece of gear in your setup is the microphone. The characteristics of your microphone will have the largest effect on how your recording sounds. While there are some super cheap mics to be found, they sound terrible and aren't worth their price, however low it may be. For our purposes, we can class mics into two categories: the standard microphones, as used in studios; and USB microphones, which can be plugged directly into your computer.
Standard microphones are more expensive and require additional equipment to power them and to convert the signal from analog to digital so it can be fed into your computer. However, they also usually give you a higher fidelity signal and are more flexible. By flexible i mean you can use them with your laptop, with a portable recorder, in someone else's studio, etc. You can also, with the aid of a mixer, use as many as you need.
USB microphones, on the other hand, are cheaper and allow you to plug them straight into your computer, as all the analog to digital conversion happens inside the mic. They make your recording setup considerably simpler and cheaper because you won't need an audio interface nor any preamps. A decent USB mic will easily sound good enough for podcasting, but there's a major downside: it can be complicated to use more than one of them simultaneously. It can even be impossible if you want to use two of the same model. There are workarounds, but they involve a relatively advanced knowledge of your OS and recording software and may not be 100% reliable. Because of this, i can't recommend USB mics for anything more complex than a two person recording setup.
2. Audio Interface
An audio interface is what you'll need if you go with a standard (non USB) mic. It will involve a preamplifier which powers the microphone and amplifies its signal, and an A/D (A: Analog; D: Digital) converter, which converts the mic's analog signal to a digital signal to be fed into your computer. It will also include some outputs for speakers and headphones. These won't affect your sound as much as the mic choice, but a bad preamp or A/D converter can introduce hiss and distortion. The good news is that you can get a solid audio interface fairly cheaply.
3. Peripheral Gear
Peripheral gear, such as pop filters, mic stands, and headphones, is also important to consider. If you get no other piece of peripheral gear, get a pop filter. I can't emphasise enough how necessary these are. Hold your hand up in front of your mouth and read something out loud. Consonants called plosives (t, k, p, d, g and b, but especially p) cause you to expel air from your mouth. When this hits a mic's diaphragm, it creates an ugly low frequency noise in your recording that gives an amateur impression.
A good mic stand is another piece of vital equipment, as you need something to hold your mic. It's vitally important that you can rely on your mic stand. I've worked on some podcasts where i could hear the mic gradually getting further and further from the speaker's mouth until "- hey where's your mic going?", but it was already too late, and while I was able to minimise the negative effects, it's better to not have anything to fix in the first place. A good mic stand will also insulate the mic from any bumps on the surface where it's sitting.
Finally, headphones aren't totally necessary, but can be good to have, and i recommend that at least one person monitor the recording in order to catch any sound problems as they happen. I'd also strongly recommend headphones if you have guests/hosts call in remotely, so your "in studio" talent can hear them without their sound bleeding into the mic. As far as choice goes, you want something that's fairly comfortable and that won't leak sound into the mic. Pro tip: unless you're experienced, always leave one of your ears uncovered, especially if you're using enclosed headphones. If all you can hear is your own voice amplified through the mic, it doesn't feel natural and so you'll have trouble speaking naturally. Even some of the best actors need to keep an ear on their "room voice".
In summary, the mic is the most important part of your recording setup and will have the largest impact on your sound. If you're running a one to two person podcast and want to keep it simple, a USB mic is the way to go. If you're planning on having more than two speakers, or if you're keen to spend a little more on a more robust setup, then standard mics and an audio interface are for you.
These really are the bare bones basics of recording gear and i highly recommend using all the pieces i've mentioned. I'll go into further detail about each category in future posts, as well as add ons that can help you out. I hope this has shed some light on the technology involved and i welcome any comments if you'd like further clarification.