1950s radio effect

So I’ve read all those thing about old radio/walkie talkie/PA effects on audacity, but I’m trying to get an effect that makes it sound like an old radio set from the 1940-1950s.

Here’s a nice (and funny) example.

Any ideas? Narrow band pass filters don’t cut it by themselves… I’ve tried that. (Please, nothing about just white noise)

The effect in the video you linked to was narrow band pass (approximately 700Hz-7000Hz) an example is attached.

If you want radio effects (there were none on the video) then try putting the search words “radio” and “noise” here
Before after 700-7000Hz bandpass (and some reverb).zip (210 KB)

AM radio doesn’t go beyond 5 KHz (although everybody wishes it would), and it goes down to 20 Hz. That’s the proof of performance for a radio station. It does have some very peculiar noise. It can have a very low 10 KHz whistle in the background. That’s two stations interfering with each other, and any electrical noise or static you happen to have laying around. It can have two stations at once.

They do not echo.

You need to know the metaphor. Transistor radio sound is going to be very different from the AM radio in my sound system, different from the Victorian Living Room console sound and different again from a Ghetto Blaster.


You can go well on your way to that effect with just the eq. That’s how they did it, but they were spoofing the effect, not doing the real thing. Old Tyme Radio had announcers that took advantage of the response of the system by having very deep voices and slightly exaggerated pronunciation. No filter for that I’ve ever found.

Another spoof buried in there is the Rudy Vallee voice. He had no volume at all so sang through a small megaphone so everybody could hear him.


All that and optical Film Sound didn’t go beyond 5KHz, either.


<<<“heterodyne whistle” >>>

Exactly. Radio stations in the US are 10 KHz apart. During the day, everything works out, but at night, you can hear two stations right next to each other. From my childhood, WGY in Schenectady NY and WFAA/WBAP Dallas/Ft.Worth. 810 and 820 on your AM dial and both rock crusher stations. Whistle City. Most AM radios have a circuit to get rid of that, but the earlier radios didn’t have one.

AM sound fidelity is half the station spacing which gives you 5KHz sound.

If you play your cards right, you can get fading, too, as the stations drifted into each other – particularly at night.

If you lived near the Mexican border, you had another problem. Mexico had little or no limit on transmitter power, so they had stations that would melt Fiats and Volkswagens in the parking lot.


I’ve had another go: 700-5000Hz and some compression (no reverb)
Before after 700-5000Hz bandpass (and some compression).zip (216 KB)

Yes, compression is called for, but I don’t entirely agree with the 700 Hz drop. They didn’t sound like telephones (300-3000). They had very good bass.

No transistor radios in 1948.

And it’s also the difference between the spoof and the real thing.

The effects can be minimal if the show is “Pepper Young’s Family” and the announcer is Don Pardo. It’s a lot more work to carry off Electro Trance on an AM station.


Oh, and Chris’s Compressor does an amazing job of simulating a radio station compression. I bump the compression from .5 to .8 when I use it.


Wow, thanks for the answers, guys.
Although I’m not quite sure how AM radio cross-over works into this topic.

So I’ll try narrow bandpass filters and equalizers and see what works.

Btw, what I’m trying to do is create a narration spiel for this WWII training video.

The vocal on the video orangel linked to has very little bass, (more like 1920s gramophone).

If you want the audio to sound like it’s emanating from a WWII radio, throw in a heterodyne whistle.

Audacity’s equalizer alone is sufficient: this is the equalization I used …
700-5000 bandpass.png
BTW If you are using Audacity’s native compressor I suggest you reverse the track, apply the compressor, then reverse it back the right way around.
This avoids the creation of spikes at the start of words, which Audacity’s own compressor unfortunately tends to add.

Is that 1.3? My Audacity eq doesn’t look like that :

And how would I add a heterodyne whistle? Tone at a certain pitch?

<<<Although I’m not quite sure how AM radio cross-over works into this topic.>>>

From the first line of the first post…

<<<So I’ve read all those thing about old radio/walkie talkie/PA effects on audacity, but I’m trying to get an effect that makes it sound like an old radio set from the 1940-1950s.>>>

<<<this is the equalization I used …>>>

Nothing with vacuum tubes in it ever came out that clean and sharp. I’d probably round off the corners a bit and make the curve gentle. And I’d still go down further on the left. There was no restriction to the low end on AM radio transmitters. They used to do big band shows from hotels and there was nothing wrong with the bass line.

The hetrodyne whistle in the US is always 10KHz because of the radio channel spacing. Other countries it could be 8 KHz.

<<<Audacity’s own compressor unfortunately tends to add.>>>

Which is one of the many reasons to use Chris’s Compressor. Trouble free volume leveling.

<<<Btw, what I’m trying to do is create a narration spiel for this WWII training video.>>>

On film? OK, skip the heterodyne whistle. Film doesn’t have that. Film does have those funny muffled optical track pops as dirt and film splices go through the projector. And they’re out of sync. Sound on Film is 16 frames behind, so you see a crack or splice in the film and it’s about a second later you hear the pop.

I don’t know how I would simulate optical film dirt in the track. I never tried. But optical film sound didn’t have any better fidelity than AM radio.

Maybe a brief blast of white noise and then muffle it with the equalizer.

Any serious sound production should be done in Audacity 1.3.x. Audacity 1.2 tools and filters are really simple and many of them don’t work particularly well.



Its’ not a constant tone. The whistle is a sine wave which changes in pitch approximately
3000Hz-5000Hz-3000Hz etc, in a sinusoidal fashion with a period of about 20 seconds.

If you look at the Freesound link I gave you’ll probably find the real McCoy rather than having to syntheise it.

[ Some quite good radio noise here … Freesound - Radio tuner.wav by Mart1001 ]

PS throw in some mains hum (50Hz Europe 60Hz USA) valve radios had plenty of that.

I still like the whistle for effect, as it will make people think it’s still 1940s-ish (mix up radio and film).

Thanks for those sound links, too. I’ll use those instead of laboring to try to make my own.

I wish they had posted a little explanation with those radio samples. Three of them are an AM radio being tuned rapidly up and down the dial, one of them is a radio left just off center of correct tuning (which makes my teeth hurt), and the last one is an actual microphone sound capture of a thunderstorm, not the storm as it appears on AM radio.

None of them sound like what happens if if you listen to a half-hour radio show. One of the samples was from a small table radio and that accounts for the boxy sound with no bass.

And no, heterodyne doesn’t constantly change pitch. Sometimes on the short wave bands it can do that, but not broadcast. I thought I heard some radio teletype sounds in one of those samples, so goodness knows where they came from.


What was the search term you used for your sample? I’m interested in the warbling heterodyne.


The warble I was thinking of was due to the tuning drifting slightly causing the heterodyne whistle to slowly change pitch in a cyclical fashion over 10s of seconds.

I’ve had a quick look on Freesound but can’t find one yet, (The Freesound search engine is unreliable).

I’ve found a synthesised version of the heterodyne whistle I was on about above…

I know Im rezzing a long dead thread, but google lead me here ergo for future googlers… :grin:

Its worth noting back in the days of tube based AM radio broadcasting the pacific north west sort of nasally news caster voice was a thing for a reason. The tight nostril, open throat, projection from the chest (and over pronouncing vowels of course) leveraged the shortcomings of the AM technology of the time for a clearer more intelligible speech. Particularly from an ‘in the field’ radio transmitting to the main station for re-transmission.

Also consider how AM works. Its Amplitude modulation. In AM 300hz on either side of the carrier is a dead zone, then up to 4000hz is the bandwidth, above which is also cut like below 300hz (This channel band is mirrored on the other side of the carrier. This is where we get upper, lower, and dual side band from). The carrier power (amplitude) is then increased in relation to the audio being transmitted. One tactic is to use a tube which is passing the carrier, and the screen decreases voltage in relation to the input audio thereby increasing the modulated signal amplitude in kind. How does this impact audio quality, and impact the effect in question? No idea. Im a tech nerd not an audio nerd. Its just some knowledge to leverage when thinking about how to fiddle your project to achieve a more authentic sound. But heres hoping it helps someone some day…

For completeness, Technology Connections has a good video explaining how film audio is ‘encoded’ optically onto the audio track of a film reel. An incandescent lamp in place of a speaker is used to vary the light exposing that section of film. Ergo just like the visual section, shine a light through the film onto a photoresistor attached to a mosfet or transistor (and further amplification circuitry) and you have recovered the sound to …some… level of quality. I imagine its possible to recreate this style of circuit with a flashlight bulb attached to an audio output and a photoresistor (maybe some extra preamp circuitry to boost, and clamp the voltages) looped back into an audio input…I might actually try that… Ill put it in its own new post though :wink:

There is now an Audacity plugin for all your retro radio needs: HelmetRadio1.5 …

An opto compressor plugin may suffice.