Component values 4-way Linkwitz-Riley filters
Crossover frequencies : Min Max
Sub : 20 160 Hz
Bass : 160 850 Hz
Mid : 750 4000 Hz
High : 4000 30000 Hz
R1 3751 ohm 3k3 + 1k pot
C1 1 nF
R2 56270 112540 ohm 27k + 27k + 5k pot 68k + 39k + 10k pot
C2 100 nF
R3 28135 ohm 27k + 2k pot
C3 1 nF
R4 68206 136412 ohm 56k + 10k + 5k pot 120k + 12k + 10k pot
C4 2.2 nF
R5 60182 ohm 56k + 1k8 +5k pot
C5 2.2 nF
R6 70337 140674 ohm 68k + 5k pot 120k + 15k + 10k pot
C6 10 nF
R7 70337 ohm 68k + 5k pot
C7 10 nF
R8 28135 56270 ohm 27k + 2k pot 47k + 6k8 + 5k pot
C8 1 nF
1. All capacitors are precision or selected film types.
2. All resistors are 1% metal film.
3. All trim potentiometers are of cermet type.
4. I recommend to build the filter without trim potentiometers and use precision capacitors and resistors. You will save a tremendous
5. Utmost care should be taken in the grounding of the filter PCB : I had to ground the balanced input ground to the chassis to elimin
6. Place the power supply (especially the transformer which should be of a toroidal type) as far as possible from the filter PCB. Plac
7. Use a metal housing to shield the circuit from external fields.
8. All filters have an inband gain of 1. I added attenuators on the outputs of the filters that adjust the levels according to amplifier ga
8. The output attenuators, which also use ceramic potentiometers, have a range of +/- 3 dB around the optimal value.
pacitors and resistors. You will save a tremendous lot of work !
d the balanced input ground to the chassis to eliminate hum.
al type) as far as possible from the filter PCB. Place extra shielding if needed.
ers that adjust the levels according to amplifier gains and speaker sensitivities.
of +/- 3 dB around the optimal value.