Cascade high Q passive w/low Q active

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If I have a sealed bookshelf speaker with a high Q of 1.6 at 150hz. I would like to add an active 2nd order high pass with a low Q of 0.31 to get a combined 4th order high pass with a Q of 0.5 to match a subwoofer's 4th order low pass.
Can this be done?
I cant find info on crossovers with Q's less than 0.5. The math seems to work for the unity gain sallen key filter if the resistor ratios are correct, but no one seems to do this. The equal component sallen key does not appear to work though, due to negative gain at Q's < 0.5.
I know all of this is theortical, so I plan on measuring the results to fine tune the set up if it will work.
It appears that a 1st order active(Q=0.7) cascaded with a 2nd order L.R.(Q=0.5) would make a 3rd order with a Q of 0.35 is this right?
Im relatively new to this if anyone can refer me to a good reference I would be grateful.

Thanks
 
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