60 hz is somewhat high, and it will drop off at 12dB per octave below that point. Which happens to match the cabin gain pretty nicely, which raises at about 12 dB per octave.
The reason the F3 is high is because the sensitivity is high and the box size is relatively small. There is no such thing as a sub that is effecient, fits in a small area and has deep bass extension. Even so, this sub should get you down into the teens without much trouble.
