What high pass filter did you end using specifically? (so I can copy you :eyebrows![]()
I have these installed which gives me a crossover frequency of 400Hz on my Kicker KSC3504: https://www.ebay.com/itm/191726642522
That being said, I think that's really too low for 3.5" speakers and I'm going to swap in some 47uF capacitors for a crossover point around 850Hz (these are about $1.50 each).
Depending on your speaker impedance, check your frequency here: https://www.v-cap.com/speaker-crossover-calculator.php