measurement comments:
best extension found with SpinFit (as reported by many), worst extension with Shure silicon tips (no surprise given the narrow diameter)
Smoothest response = Shure Olive --> interestingly seems to dampen some of the low mid resonances, cool!
Comply Ts500 also has smoothing characteristics in low mids, but worse extension than Olive.
I wouldn't pay too much attention to the very low frequencies roll-off exact values, but in general the foam tips will have a natural high pass filter effect (not perfectly sealing)