Good Intentions. Bad Room.

The room you record in…

can have a huge impact on the quality of your podcast audio. And the quality of your podcast audio can have a huge impact on how your listeners perceive your content and message.

Given these facts, it’s funny (but not “ha-ha” funny) that room acoustics aren’t discussed more often by podcasters. This post tells you what you need to know.

Instructions:

Watch the video above – It contains rapping. You’ll enjoy it. Trust me.
Read the entire post below – It contains a lot of good learnin’. And good learnin’ makes you wicked smart.

(Just) A Little Theory

When you speak (or make any sound), sound waves travel away from your mouth.

Almost immediately, those sound waves hit the walls, ceiling and floor of the room and bounce around for a short period of time. Once they lose energy, they stop bouncing and you can no longer hear them. It’s silent again.

In small rooms with parallel walls made of painted drywall — that is to say, most rooms in most homes — sound waves bounce around with a lot of energy for a fairly long time.

Note: In acoustic terms, a “long time” is really only a fraction of a second. But that’s long enough to produce what’s called reverb.

The Bad Room

This is what a hand clap sounds like in a bad room — one with a lot of reverb. This is a short 2s clip. Turn up your speakers or headphones and listen carefully for the reverb.

Did you hear it? If not, turn up your volume, play it again and listen more closely.

Here’s what what that same hand clap looks like in an audio editor.

NOTE: The background noise you hear in this recording is an airplane flying over my neighborhood as I was recording. Can’t catch a break.

The reverb in this room (my living room) is 360 milliseconds — that’s less than half a second.

And if I were to record an entire podcast episode in that room, it would sound — at least to me — like it was recorded in a submarine.

And in case you’re wondering… submarines don’t sound… good.

The point here is that a half a second worth of reverb can be distracting to someone listening to your podcast.

Distracting your listeners is one thing. But the real danger lies in giving your audience the impression that you either, a) don’t care about the quality of your audio or b) don’t know how to record properly.

It’s important to note, your goal should never be to remove all the reverb in your room. A small amount of reverb is good — it makes your recording sound natural.

Instead, your goal should be to reduce reverb to a level at which it’s not a distraction and doesn’t interfere with your show’s message.

The Good Room

Here’s a hand clap in a “better” room.

And that same hand clap in an audio editor…

NOTE: Both the good and bad hand claps were recorded with exactly the same microphone on exactly the same recorder at exactly the same gain settings. The only difference in the set up was the room they were recorded in.

Did you hear a difference between this hand clap and the previous one?

You should have. The difference isn’t subtle.

In this room, the reverb is only 125 milliseconds — almost 3 times less than the “bad room” in the diagram above.

The “good room” is my studio. I record here often and the results are great. Not perfect by any means. But consistently good.

What Can You Do About It?

If you’ve been recording in a bad room, what can you do to improve your life? Other than losing weight? And quitting smoking?

Good question.

Here are a few suggestions:

1. Acoustically treat your room – This is a less than ideal solution because: a) you need to have a dedicated podcasting room (and that’s not always possible) and b) buying and installing professional bass traps can be expensive. This is a good solution but it’s not a cheap or easy solution — especially if you’re new to podcasting. Read on.
2. Choose a better room* – Not all rooms sound the same. Rooms with non-parallel walls (i.e. rare in most homes), dense materials (i.e. upholstered furniture: bed, couch, recliner, etc.) and irregular-shaped items (i.e. furnace, water heater, Biggie Smalls, etc.) will sound better than small, square rooms with bare walls.
3. Record in your car – Say wut??? That’s right. As strange as it sounds, a car can make a great recording booth. Most of the surfaces are slanted, the seats, ceiling and floor are upholstered or carpeted and with the exception of the car’s windows, nothing is flat and hard. Give this a try sometime. It doesn’t even need to be an expensive car — a Kia sounds just as good as a Porsche. Maybe even better.
4. Use the right microphone – It’s important to note, the “right” microphone is not necessarily an “expensive” microphone. Don’t believe anyone who tries to convince you that you need to spend more money on recording gear to get reverb under control. That’s total BS. The reality is, the right microphone might actually be much, much cheaper than the one you’re using right now.

* Note: Before I installed bass traps in my studio, the best-sounding room in my apartment was a laundry / utility room. It contained: a washer and dryer, a furnace, a water heater, a shelving unit stacked with cleaning supplies and a couple of clothes hampers. It wasn’t a “terrific” sounding room but it was the best in the apartment.

In closing…

Now you have a general idea of why some rooms sound better than others and how to use that knowledge to improve your podcast recordings.

What are your thoughts on room acoustics?

Have you had bad recording experiences?

Ever done it in a car?

Let me know in the comments below.

Peace,

PS: You want to know what microphone you should use, don’t you? Don’t deny it.

You want me to tell you.

And I will.

Soon…

Gear Used In The Video

Neumann TLM102 – Condenser Microphone (Test)
Shure SM7B – Dynamic Microphone (Voice Over)
Tascam DR-100mkii – Audio Recorder
Sony MDR-7506 – Headphones
GIK Acoustics – 244, Tri-Trap Corner and Monster Acoustic Bass Traps