Fountek FRI-135ex fullrange-Passive EQ question
I am new to speaker building and I have built pair of the manufacturer suggested bass reflex boxes for my new pair of Fountek FRI-135ex fullrangers. Stock with no EQ they sound decent but are a little ragged on the top end so I built the EQ circuit found in the PDF from Fountek. When the circuit is hooked up, it dulls a lot of the top end and upper midrange to the point where it sucks the life out of the speaker. My problem is I do not have a complete understanding of how these EQ circuits work so I just followed the diagram with the exception of one of the inductor values. The value needed was .548mH and I used a .55mH thinking that it was close enough ...but I am ignorant on the subject(working on that). I am hoping somebody might be able to shed some light on what the circuit is doing and maybe provide advice on what or if I can change a component value in order to back off the overall effect of the EQ circuit a bit since it seems like dialing it in somewhere in the middle would be the best case. I have researched other EQ circuits and BSC's and have not found anything similar yet (still looking) nor have I found much in the way of people completing projects with this driver. Any help offered is greatly appreciated, thanks in advance!
PDF link to diagram in question: http://www.madisound.com/pdf/FR135EX-Encl.pdf