Mar 12, 2008

Understanding the Recording Environment

Understanding the Recording Environment
So far we've spent the entirety ogling all kinds of cool audio equipment that will produce higher-quality podcasts. However, there's a very important element that we haven't even touched on: your recording environment. Any audio engineer will tell you that the environment is a huge contributing factor to the quality of your production. All recording studios are specially built to provide an environment where things sound good.

Building recording studios is very skilled work, because recording studios must be capable of recording anything that walks through the door, from audio books to rock bands. For podcasting, we're trying to create a neutral environment, so that the sound of the guest's voices cut through. The last thing you want to hear is the sound of the room you're recording in.

A classic example is the sound of bathroom tile. We all sing in the shower because the highly reflective tile surfaces around us reflect our voices back to us, bathing us in a sea of reverb. Everyone knows exactly what a bathroom sounds like. You can't record in there, because folks will know you're recording in the bathroom!

The same goes for small closets or even small offices. Our ears detect the size of rooms by the reflections we hear. Think about that the next time you're stuck on a boring conference call. You can tell in a split second how big the room is on the other side of the call, and the sound quality is almost always horrible. That's because offices with whiteboards, windows, and big wooden tables have lots of reflective surfaces that fill the room with reflected sound, which is what makes it hard to listen to for long periods of time.

What you really want is a room that is nice and quiet, one that doesn't have too many reflective surfaces. If your room doesn't sound good to start off with, it's not too hard to make it sound much better with some sound treatment.

Sound treatment
If you've ever been inside a radio station, you know that the studios are nice and quiet. If you look around, you'll notice that the walls are treated so that they absorb sound. They have to be built this way, because there are microphones all over the place and all they want to broadcast is people's voices — not the sound of the room. Because you probably don't have the money to build a studio from scratch, you can do the next best thing: Use acoustic panels to treat your walls.

Acoustic panels are large pieces of foam or some other sound-absorbing material (see Figure 1). These panels are attached to walls and ceilings to reduce the amount of sound that is reflected. This makes the room sound neutral, because no sounds are reflected to give our ears a sense of space. Consequently, the sound going into your microphone is just your pristine voice, and nothing else.


Figure 1: Acoustic tiles can turn a terrible sounding room into a great recording environment.


You can do other things to improve your environment, some of which are just common sense. For example, if you're recording a conversation around a large table, place a tablecloth on the table. Not only does the tablecloth damp down any reflections from the tabletop, but it also absorbs noises like people putting coffee mugs down, tapping pens, and doing lots of other distracting things. If your space has windows, consider buying curtains and closing them when you're recording. Anything you can do to minimize large reflective surfaces will help.

Studio layouts
If you're going to create a dedicated space for your podcast production, take some time to think about how you're going to use it. You should consider different studio configurations, depending on how you're going to produce your programming. The simplest is a single operator studio.

Single operator
If you're going to be the producer, engineer, and star of your own podcast (of course), then you're probably going to do everything in the same room. You need enough space to accommodate all the equipment you've accumulated after reading this post and enough space to accommodate however many guests you plan on having. Remember that your guests probably will want some table space of their own to put their coffee, their laptop, and whatever else they've brought along. Make sure they have access to power, because they'll want to recharge all their gadgets during the podcast. (Make sure they turn off their cell phones.)

Be sure to have your equipment mounted in a special rack, or on a separate table, to protect it from spilled drinks. Equipment racks often have the added benefit of being on wheels, so when your production is finished, you can roll the equipment out of the way until the next time.

Another thing to consider is the noise generated by your computer. If you're using a modern desktop machine with a high-powered processor, the noise made by the cooling fans may be picked up by your mics, particularly if you're using condenser mics. It's best to minimize this as much as you can. One good approach is to replace the standard fans and power supplies with low-noise versions available from vendors such as PC Power & Cooling (http://www.pcpowercooling.com). If you don't feel like shelling out the extra money for quiet fans, you can reduce the amount of noise picked up by your mics by moving the offending machine as far away as possible. You also can attenuate the noise with acoustic foam or small baffles.

Talent + engineer
If you're fortunate enough to have some help producing your podcast, you may want to consider setting up a studio where the talent (meaning your guests and you, the interviewer) is in a separate room from the equipment. This accomplishes a few things. First, the audio engineer works without worrying about keeping absolutely quiet. Second, audio equipment can be somewhat intimidating to some people, so doing the interview in another room can sometimes make for a more relaxed, natural interview.

No comments: