Wayne Parham Messages: 18752 Registered: January 2001
Illuminati (33rd Degree)
No, it should be 5mH. It's a gentle filter that does have approximately a first-order slope, but it isn't a crossover, it's essentially EQ. The midhorn increases efficiency at midrange frequencies, but not bass. So the whole L1/R4/R5 network is a response shapong network.
As an aside, pseudo-first-order is just a name I gave to single-component crossovers without a Zobel. I sometimes also refer to them as pseudo-Butterworth networks. All I really mean by that is a reminder that the filter isn't pure first-order unless the load is resistive - which it isn't. So it looks like a first-order filter, but isn't really. It usually forms a first-order slope down low, but more of a shelved response up high. It cannot maintain 6dB/octave through the whole band because the load impedance changes with frequency.