Frequency range vs frequency response

I should know this but am still fuzzy on it. Could someone explain the difference between frequency range and frequency response when looking at specs of loudspeakers? I know specs are only part of what you base a purchase decision on but which one of these tells the truer story about how low they can reproduce bass levels? Each loudspeaker has a low end value in HZ for these two measurements but they differ. Which one gives you the best idea of how low it can go? What's the difference? Many thanks.