KNX (1070 AM) had a simulcast with 97.1 FM for about five years. Interestingly, the FM signal, like the AM, was mono, most likely due to the wiring of the studio (though at one time KNX did use an AM stereo broadcast system).
This gives a unique opportunity to compare the sound of the AM and the FM signals using a good tuner. So I did. The following are recorded using a Carver TX11B tuner, capable of wideband AM and FM. Take a listen to the samples, and see if you can determine which is AM, which is FM, and which one sounds better to you.
Please listen to the full samples, so that you are not influenced by programming elements such as traffic reports vs. commercials.
First up is a sample switching between the AM and FM signals (no, I am not telling you which is which)
Next up is Sample 1
And finally, Sample 2
Which do you think sounds better, Sample 1 or Sample 2?