"Impedance varies greatly near resonance and is affected by enclosure loading. The rated 'nominal' impedance is estimated at 1Kohms but, in the bass, the difference can be huge." -Kr4
The impedance peak(s) at system resonance will cause a simple series capacitor or textbook L-C filter to exhibit non-textbook behavior. The problem is, the response is insufficiently suppressed at the resonant peak(s). Throwing a bigger capacitor at the problem just results in a deeper frequency response "saddle" above the peak.
The highpass filter should be optimized for that particular driver's frequency response and impedance curve, and doing so is largely a matter of trial and error, often calling for additional components in the circuit. Not saying it isn't worth taking a shot at, but this is one of those things that's more complicated than it appears at first glance, and the component cost to really do it right can be rather daunting.
A small, high-quality series capacitor in between the preamp and power amp is often a more elegant and cost-effective solution. Find out the power amp's input impedance, and calculate the capacitor value for the frequency you want using that number. You'll have to do some soldering involving RCA jacks and plugs, or balanced connectors, but you'll come out way ahead on parts cost for equivalent sound quality.
Imho, ime, ymmv, etc.
Duke
dealer/manufacturer
The impedance peak(s) at system resonance will cause a simple series capacitor or textbook L-C filter to exhibit non-textbook behavior. The problem is, the response is insufficiently suppressed at the resonant peak(s). Throwing a bigger capacitor at the problem just results in a deeper frequency response "saddle" above the peak.
The highpass filter should be optimized for that particular driver's frequency response and impedance curve, and doing so is largely a matter of trial and error, often calling for additional components in the circuit. Not saying it isn't worth taking a shot at, but this is one of those things that's more complicated than it appears at first glance, and the component cost to really do it right can be rather daunting.
A small, high-quality series capacitor in between the preamp and power amp is often a more elegant and cost-effective solution. Find out the power amp's input impedance, and calculate the capacitor value for the frequency you want using that number. You'll have to do some soldering involving RCA jacks and plugs, or balanced connectors, but you'll come out way ahead on parts cost for equivalent sound quality.
Imho, ime, ymmv, etc.
Duke
dealer/manufacturer