Passive low-pass passive for line input - 2nd part
Please see my previous thread (date 8-6-2011). Wishing to use the high-level output of my master amplifier to pilot a secondary amplifier for a subwoofer through a passive filter, I'd want to know your opinion about these two ideas:
1. Admitting to use the classic LC circuitry calculated by Wintermute on a 20 ohms load and a frequency of 60 Hz (to be able to use inductors of 100 mH, easily foundable..), being necessary a resistive partitor to attenuate the signal, can I put a 150 ohms resistor in serie before the filter and the 20 ohms resistor in parallel after the filter? In other words, can I place the filter between the node of the resistive partitor of 150/20 ohms?
2. There may be a second way, to obtain a simpler 2nd or 3rd order passive filter, using a serie of RC cell all cutting at the same frequency but using in veery cell a resistor with a value at least greater by a factor of at least 10 than the previous one, for example with a 100 ohms resistor in the first cell, a 1.000 ohms in the second, a 10.000 ohms in the third and so on, in dependencie with the ampifier input impedance. Can it be a good way? How can it go the phase of this system?
Thank you again:-)