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sharper cut for my passive HPF... passive - line level signal - 100hz - almost like a wall, if possible, i like play around with its sharpness
A simple R-C filter is 6dB/octave max, with a soft corner.
Cascaded R-C gets steeper way-down, but still a very soft corner.
We can bump the corner with amplifiers. That's cheating. It used to be expensive.
We can get "any" filter shape with passive components. Loudspeaker crossovers only skim the surface. There are fat books on the topic. Very steep filters need very many very good components.
How steep does audio really need? If your material is "normal/flat", anything over about 10dB/octave is not much more useful due to masking. OTOH, sometimes we have to take garbage. Truck rumble leaking through the walls, a bass-amp that booms 70Hz.
There is a class of "passive" passive filters which really depend on "excess amplification". Since amplification is now cheap, we often have <1K sources driving >10K loads, We can tap some of this "excess" to simplify filter design.
The choke will likely cost $10, and the cap close to a buck. Need two each. The chokes will want to suck all the hum in the room. The choke might distort, though the most available ones are OT and B+ filter units which won't be strained here. OTOH, a dual opamp is $0.50, resistors almost free, and active-filter caps can be scaled to dime-price.