So I have a simple passive Hi Pass filter a 40uf fat one in series with a 20uf thin one across a 16 ohm diaphragm voice coil.
I get 13.33 uf and a high pass of 6 db per octave at 750 Hz odd.
So what happens if I add an L pad to our little circuit so the sixteen ohm wire-wound track replaces the voice coil and the wiper contact is lead to the voice coil then bypass the L pad with a one micro-farad cap.
Will rolling off the L pad leave 10 Khz and above in a shelf un attenuated and what phase cancellation will result if any.
PS I have a pair of large format Vitavox multi-cell horn units with a Coral M104 drivers that are beautifully flat down to 300Hz.
At the top end It rolls off smoothly to about 3 db down by 20K as I have loads of spare efficiency. is this a good engineering practice.
To bypass or not to bypass that is the question?.
What's the phase issues and whotnot Bill?.
Simple 1st order passive crossover question 
Somebody Please Opine? 
