I can only report on the measurements I got with each filter. Good news is there's variations in bass from one filter to the next, that was the main objective in posting the measurements in the review.
As far as there being a difference in sound between the longer and shorter filters, the longer filters measured a decibel or two leaner in bass ranges, and a decibel or two up in higher frequency ranges. The difference is miniscule and there is no perceptual difference in sound.
As far as there being a difference in sound between the longer and shorter filters, the longer filters measured a decibel or two leaner in bass ranges, and a decibel or two up in higher frequency ranges. The difference is miniscule and there is no perceptual difference in sound.