How To Sync Radio And TV For A Simulcast - A Simple, Free Method

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Joined: 02/12/2009

If you'd rather listen to your local radio sports announcers than the national TV broadcasters and they are out of sync, here's the trick.

It's not as simple as just turning off the TV's sound. Ever since the 2004 Super Bowl "Wardrobe Malfunction," TV networks have employed longer and longer delays to catch potential... slips. For example, the 2012 World Series broadcast delay was over 20 seconds. But radio stations don't use much of a delay. So, since the TV feed is well BEHIND the radio, we can't briefly "pause" our DVRs to set it back. What we need is a way to delay the radio.
Radio Delay Screenshot

I'm an audio engineer, and I have used expensive studio delay units and software in the past. But I wanted to find a solution for anyone to use. I finally found a free app that does it! Just download the "Radio Delayer" Mac application in the middle of this page (where it says "download the Max/MSP application from this link"):

You don't need any other app, unless you want to listen to a web stream from a Mac application, then try the free Soundflower or the fully-featured Audio Hijack Pro to route the audio within the computer. Tapping into streams is described on that page.

For delaying AM radio you will just need:
A Mac with analog audio in and out (some new macs don't have a separate input).
An AM/FM radio tuner with an output. If you have a receiver with built-in amp/tuner, try the "tape rec" outputs. These are most likely RCA jacks.
Two of these cables: 1/8"-to-two-RCAs.

First, plug the output of your AM radio tuner into the Mac's line input, plug the Mac's output into your stereo. Then fire up Radio Delay. (If you only have one radio receiver/amp, try the tape loop, out via the "rec" and back in via the "play".)

In Radio Delay, click "settings", and set the input to "built-in input." Click the speaker icon to turn it on. Bring up the volume slider SLOWLY because the volume starts loud. Upon the first sound, the app quickly auto-adjusts the level down.

Once you have your levels set, click-and-drag on the number at the bottom and set it to match the delay. Click to the right of the decimal point to fine-tune it in tenths of a second. For baseball, a good cue is the sound of a ball hitting a bat. Radio Delay can be adjusted up to two minutes!

For the 2012 World Series, the delay between Fox TV and KNBR 680AM in San Francisco was about 24 seconds.

A final tip: I noticed that the Radio Delay app doesn't cope well with changing cables while the application is running. Best to get everything plugged in before launching it.

Enjoy your home team announcers!

Joined: 02/12/2009

Just found a page that describes how to do this with a PC. It also has tips for doing this with a Roku 3 box.

That same site has a page which collects some Mac ideas, but none of them go beyond 8-10 seconds of delay.

This app for PC is similar to the Mac app I've listed above.