Tuesday, October 9, 2012

Vintage Radio Sound Effect

Audacity is a free sound editing program that's ideal for recording and editing clips for game use. It's surprisingly powerful, but easy enough to use that you can have finished audio just minutes after installing it. This is a quick and hopefully easy tutorial on recreating the tinny sound of a vintage radio using the program's standard settings.

For purposes of the demonstration I'm assuming that you're running the latest version of Audacity (v 2.0.2) on a Windows machine, have a microphone connected to your computer's sound input, and have a basic familiarity with recording audio .

First, you'll need to have some narration to work with. If you're new to the program remember that recording is as easy as clicking the "Record" button, the one marked with a red circle, in the Transport Toolbar. You'll find it in the upper left-hand side of the screen.

One thing I wanted to mention is that you shouldn't get hung up on audio quality at this stage. A simple headset or chat microphone is fine for this kind of thing. Once you're done recording your screen should look like this.

That squiggly blue line is your waveform, a representation of the sound you just recorded. I've recorded mine in mono, but yours may be set for stereo by default. In that case your waveform will have a left and right channel. For our purposes it doesn't really make a difference.

Now we need to recreate the tinny sound of a vintage radio. We'll do this by removing the low-end and high-end frequencies from the audio you just recorded using Audacity's "Equalization" function. Just click on "Effect" in your upper screen and then select "Equalization". It's the tenth entry down in the menu.

Now you'll be looking at the "Equalization" screen. Check the "Graphic EQ" option. It will let you see exactly what frequency ranges each selection will modify. Then from the "Select Curve" drop down pick "Bass Cut". The equalization profile should look like this:

Click "Preview" to hear what your audio will sound like once the effect is applied. Notice how it sounds much flatter? It's not quite where we want it, but it's almost there. Click "OK" to apply the effect.

Now we're going to do the same thing, except this time we're going to apply the "Telephone" filter from the "Select Curve" menu. Your "Equalization" screen should look something like this.

Preview the effect if you'd like and then click "OK" to apply it.

Ta-da! We're done. You can playback the finished audio by clicking "Play", the button with the green triangle, in the Transport Toolbar.

In essence we've used Audacity's pre-set equalization curves to first remove the low end of our audio and then remove most of the high end. The result is a flat, tinny sounding effect that does a serviceable job of reproducing the sound coming out of a vintage radio. You could do exactly the same thing in a single pass by adjusting the settings for each frequency range in the "Equalization" effect screen, but I wanted to stick to using the presets so beginners can get their feet wet.

Here's a clip of what the effect should sound like. The first part is my original narration, the second half is the same audio with effects applied.

If the embedded player is wiggy you can hear the clip over here at SoundCloud.

You can save your finished audio file by selecting File>Export from the upper edge of your screen.  Because Audacity is open-source it doesn't come with a default option to save your files as an MP3, but standard WAV format should be fine for most purposes.  You can save your work as an MP3, but you'll need to install the LAME encoder to do it.


CoastConFan said...

Propnomicon can verify this:

Keep in mind that the recordings we have are distorted for a couple of reasons. Audio from the 20s and 30s was clipped in the upper and lower ranges compared to what we have now, i.e. it was more midrange. Also electronic amplification on the microphones didn’t really come into it’s own until after 1932 or so. That means people yelled into microphones and into sound recoding devices for records, making for distortion.

Secondly, much of what we have are secondary recording. That is to say, the sounds were broadcast over the air, received by a radio (perhaps a poorly tuned one or one of lower quality) and then recoded via wire recorder and the like. The best old time radio shows, as far as reproduction quality are those that were transcribed to disk for later replay. Generally, radio was not copyrighted and was considered a disposable medium, so little survived, and much of what we have today was recorded by amateurs during broadcast

Thirdly, outside of records the recording medium would lose quality and playing it back gave in impression that the original broadcast was originally poor. Also consider that there were cheap radios which still cost $40 new, and then there were radios that cost $500 and up! The high end 7 tube radios had excellent sound and superb speakers. Don’t be fooled in to the cliché that old technology was highly inferior and follows a linear track to the present day. High quality radios reproduced exactly the sound from studios.

So if you are making a recording to play over radio, let’s say a news broadcast, don’t get too carried away with making it sound bad unless: it’s supposed to be a distant, distorted broadcast over a cheap, badly tuned radio, with terrible atmospherics, then go for it.

Alex Kaeda said...

That awesome.

Now I need to make a couple cd fulls of 1920s/30s music with news broadcasts mixed in every 20 minutes.

Thank you!

MikeP said...

@CoastConFan - interesting stuff...I might add that you should also consider your audience when determining how much distortion to use.

You can make something sound very historically accurate, but it wouldn't be what people expect. When someone sees an old looking radio, be it a $40 or a $500 one, they expect it to sound old, or what they perceive as old.

I find that sometimes I have to balance my need for historical accuracy and what people think history was like in order to draw them into the scene.