Over the past 50 years or so, the quest for the greatest quality audio (or fidelity as it is better referred to) has taken sound engineers to new places. From valve tube technology through to the digital world, its all been about creating a better sounding recording. Consider the distribution chain from the creator of the sound to the consumer (the listener):
- Creator makes sound
- Microphone picks up sound
- Sound is pre-amplified
- Sound is captured and converted to digital format
- Sound is recorded to media
- Sound is cleaned & mixed
- Sound is produced into final delivery package
- Sound is delivered to listener
- Sound is consumed (listened to) on listener's equipment
There's a long road that some sound goes through to get from an idea of its creator to the consumption of the listener. Clearly the most important thing a creator can focus on is WHAT is being recorded, rather than the technology of HOW it is getting done. But many the great works of audio have been recorded in poor quality that reduces the listening pleasure of the consumer. With today's inexpensive computer technology, it doesn't have to be that way anymore.
You can improve or negatively affect audio quality at any point in the chain. However the microphone is often the most overlooked and most critical point.
But before we take a look at microphones, let's start with the listener's equipment first. I'm suggesting focusing on this because it determines if all of your hard work will be for nothing if the quality of the listener's equipment is minimal. If your listener is hearing your audio through some inexpensive computer speakers that can't reproduce the sound quality that you could have, then there is no point to spending a lot of time and money trying to get the ultimate quality of recording. The $10 pair of speakers on their computer can probably produce the equivalent of 'AM Radio' quality so recording in some high fidelity format is going to be lost on a listener with that equipment.
However in today's world, inexpensive MP3 audio players are plentiful and most of these have the audio on them consumed through headphones or earpieces. This is very different to the average listener equipment setup of the 1980s for example, where every man's pride and joy was the stack of audio equipment they had in their home and their ever reaching quest to move from LP records to CDs 'because it just sounds better'. But even with thousands spent on high quality audio equipment, they would still have some trouble reproducing a decent set of today's $50 headphones on the average iPod. This means that your listeners are interested in high fidelity recordings to hear on their devices, because they can now really enjoy the difference.
What percentage of listeners use portable MP3 players? Although we don't have hard research to give statistics on this, we feel its probably somewhere around 75%. So if you think that your listeners are sitting in front of their computer hearing your audio, you are probably mistaken. They are taking advantage of times of the day when they can focus on your podcast episode – while driving to work, or exercising at the gym, or waiting for a flight, etc. These are the key times that you can be heard when they have the undivided attention to hear what you have to say. And yes, they are not sitting in front of the computer at these times.
So let's go back to the very start of the chain, now knowing that we have to be serious about audio quality in our recordings. The worst thing you can do is record on a poor quality microphone setup because there is no 'magic' that you can do to boost the audio quality if the raw material is bad to begin with. It's true – those 'magic' features in that audio software or rack equipment that they tried to sell you that is supposed to cure all bad quality sound recordings are snake oil if you have a poor quality microphone to pick up the sound in the first place. You'd be far better to invest in a decent microphone than spend thousands on better quality recording systems or editing software.
And a decent microphone is not expensive. Start with $100 and you can have an incredible quality sound recording instrument. Companies like Alesis, Blue Audio, Shure, Sennheiser, etc. offer high quality microphones that are suitable for Podcasting. You will find lots and lots of reviews on these on the Internet.
But here's a really key and cheap tip for you. No matter how good quality your mic is for picking up the sound, there are two types of sounds you DON'T want it to pick up. The letter 'P' when spoken creates a popping sound on most microphones, and moving air creates a wooshing sound. You should strive to eliminate both from your recordings. How do you do this? Simple. You can get some nylon from an old pair of stockings and drape it over a coat-hanger creating a shield, and place this in between your mouth and the microphone. Or you can purchase an inexpensive and professional 'popper stopper' product from most audio equipment resellers for about $20. Some microphones come with their own air filters to help with this, but my experience has shown that a popper stopper in front of a raw microphone in an environment with minimal ambient noise and moving air is the best solution. This is the greatest thing you can do to increase audio quality with the least expense. Test it by saying 'Peter Piper picked a peck of pickled peppers' into your microphone and see if the recorded audio contains or has eliminated the popping sound from the 'P'. If it has, you have solved this most commonly found audio recording problem.
Assuming you have a decent quality microphone and setup to capture the sound, you now have to follow the chain through to where it is being recorded. The cable quality that you choose can affect the audio. Use only professional audio cabling, and understand that some high end microphones don't send the same level of sound to the recording system. Some high end microphones also require a power source that is sent from the pre-amplifier (the device you plug the mic into – typically a mixing board). This is commonly referred to as 'phantom power' and you need to determine if your mic requires phantom power to run because this will dictate what you can plug it into. Most $100 microphones will not require this.
Mics on their own cannot produce a signal that is strong enough to just be recorded without going through a 'pre-amplifier' stage. A pre-amplifier (or 'pre-amp') as they are referred to, will boost the signal level to get the best quality audio saturation from the mic. This boosting affects the sound quality. In some cases, it can improve it and in other cases it can damage it. Using consumer grade audio sockets on computers for microphones will damage audio quality because they are not designed to maximize the sound quality and introduce degredation immediately. However you can use an external microphone pre-amplifier to maintain and improve the audio quality before you convert the sound into digital form. In fact, some companies offer bundled microphone preamps and 'analog to digital' converters all in one. This is usually the case with any USB connected microphone system.
The ultimate solution here is a USB connected microphone. This means that you are using the microphone to not only capture the sound quality, but also to pre-amp it and convert it to digital format so that it won't be degraded by the computer. That's great as long as you know that you are now relying on the microphone to do a lot of work. If any part of its job negatively affects your audio quality, then there is nothing you can do about it because the whole system is a 'black box' that just works. You are sacrificing control for convenience here. But I'd suggest that in 99% of all cases, the fact that some smart audio engineer put all of the pieces of the chain together normally means that you can rely on high quality sound being recorded if you have a decent quality microphone with a USB interface on it. The Alesis Podcasting Kit products, for example, do exactly this. They bundle a high quality microphone with a USB interface, and therefore a pre-amp and analog to digital convert all into the microphone and since they specialize in high end sound recording equipment as their core business you can rely on the fact that your audio quality isn't compromised.
If, however, you wish to have control and do this with lots of separate units, you certainly can do it but it will be much more expensive. A decent microphone pre-amp unit that you find in most recording studios will probably set you back $500-$2,500 alone. Then you'll need a mixing system that can convert the analog signal to digital which will cost thousands more. This is what you pay big bucks by the hour for in a professional recording studio (not to mention the environment, staff and outboard gear). But most podcasters have a hard time justifying this kind of expense, so stick with a high quality microphone to USB package.
Once you have the audio coming into your computer as digital sound, you can then choose from the many recording products that will allow you the convenience of focusing on what you are saying rather than how you are recording it. Products like Propaganda are excellent for simplifying the recording process for podcasters, and mirror the easy systems that radio talk show hosts have enjoyed for decades. The idea of allowing you better 'real time' control over your recordings will boost the excitement and energy in your recordings that conveys well to the listener. You will also need some form of editing system.
Finally you should also be aware of compression. Audio compression is an effect that you apply to sound to reduce the loud points and increase the quiet points so that your audio has a much more consistent volume level. This is really important and something I see many podcast hosts forgetting about. A decent audio compression level will allow your listeners to focus and enjoy the content rather than feel that their ears have become pinballs in a pinball machine – adjusting to the loud and working hard to pick up the soft. This just becomes tiresome and isn't enjoyable and you'll lose listeners if you don't combat this with an audio compressor of some sort. Most audio recording software has a function to compress audio, so if you are not using it dig up your manual for the software you use and find out how it works. The investment in understanding and using compression will pay off for you.