whats first order filter on spkr's cross over ?

Hi, There are few spkr manufacturer that claimes using so called first order filter on the cross over network; has unique lower frequency(?)sound reproduction ?? Would somebody please explain whats does it really meant ?(whats first order filter anyway ?)
Thanks in advance
It means that the slope rolls off frequency at 6db per octave. For example, if you take 100hz frequency with a 6db filter, it will be down 6db at 50hz and 12db at 25hz(2 octaves shown here)
6db filters create less phase shift and as a consequence are considered to affect harmonic structure less than steeper sloped filters such as 12db or 18db, etc. All time and phase coherent speakers use a 6db slope filter in the crossover along with offsetting the drivers for temporal alignment(time alignment.) I cannot attest to the bass alone because there's more to the design than just the crossover.
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