Heck, what do I know? I'm hearing impaired. Not sure about equalizer, but I can tell you there's only one speaker. The settings are Mello, Music, and Voice. My only goal is to get the radio to work as it did in 1949 or so. I'll be able to hear enough to know the radio is on, but my ears aren't critical enough to know what the sound quality is. I can identify static or voices or music, but that's about it. This is a tube type radio we're talking about here, and it's likely not too sophisticated. But it does have something called a vibrator built in, and I kind of suspect the tone control affects the vibrator frequency. I'm told the vibrator creates a noticeable hum, and I'm guessing if that hum can be controlled, it might cancel out noise from a weak signal.
But that's just a guess, which will get you a cup of coffee at SpeedWay if you throw in two bucks.