The baffle step isn`t part of the acoustic power (efficiency) response of the woofer. In basis it`s the acoustic dimensions that put extra forward directivity to the system. In theory a 6db/octave rise from low to high freq.
gr. Marcel
Yes, a change in directivity.
Best literature I've found says the directivity increase begins when box dimension is about 1/10th wavelength, and is fully in effect when box dimension is 1/2 wavelength (potentially 6dB).
So maybe it is better described as a baffle ramp, than as a step.
I think it got the name step because once it reaches +6dB, there is no further dB rise with increasing frequency.
I guess I'd look at off-axis response for directivity changes.... vs your box dimensions,.....to try to separate natural response from any baffle step response.