e circuit, is a classic circuit of electronic crossover. Stand in for, the circuits of passive crossover that exist in all loudspeaker three way. The difference is in that, it should anymore we use for each loudspeaker a separate final amplifier. Thus for loudspeaker three way, it will be supposed we use six final amplifiers. This make has the negatives of cost and space that occupy the extra amplifiers. From other however the quality of repeated sound changes radically to best, one and the regulation on part of parameters that concerns each loudspeaker, it is much easier and technically feasible. In the particular circuit the signal that emanates from the exit of preamplifier, is applied in the IN and via the RV1 we regulate the total level.
The IC1 makes simply a adaptation of entry and isolation of circuits, between them. The IC2A-B and the materials around them shape a high pass filter with bent -24dB/oct, with frequency cross fc=3100 HZ, that drive the loudspeaker of high. The IC2C-D (high pass) and IC3A-B (low pass), with around materially, shape, a band pass filter, with bent -24dB/oct, in the frequencies fc=400HZ and fc=3100HZ, respectively, that drive the loudspeaker of mid. Finally the IC3C-D, shape a low pass filter with bent -24dB/oct, that drive low loudspeaker. The levels to the amplifiers, we can him regulate with the trimmers TR1-2-3. The frequencies of cross, can change, according to the characteristics of loudspeakers that we use in our loudspeakers, it is enough we use the types of calculation, that concern the crossover with bent -24 dB/oct. All the resistances should be metal film of tolerance of 1% of 1/4W and the capacitors as much as possible more near in the theoretical price that exists in the list of materials of (propylene, mylar, MKT). It is meant that make a such circuit for each channel.
R1= 10Kohms TR1-2-3= 10Kohms trimmer C18= 680nF 63V MKT
R2-4-10= 11Kohms (22K//22K) C1= 4.7uF 63V MKT C19-21= 3.3nF 63V*
R3-5= 22Kohms C2-3-4-7= 100nF 63V ceramic C22-24= 20nF 63V (10//10nF)*
R6-8-14= 28Kohms (56K//56K) C5-6-8-9= 3.3nF 63V* C23-25= 10nF 63V*
R7-9= 56Kohms C10= 220nF 63V* C26= 2.2uF 63V MKT
R11-12-13= 11Kohms (22K//22K) C11-12-13-14= 10nF 63V* IC1-2= TL074
R15-16-17= 28Kohms (56K//56K) C15-17= 6.6nF 63V (3.3//3.3nF)* IC3= TL071
RV1= 47Kohms Log. C16-20= 100nF 63V MKT C* is polycarbonet, polypropylen, MKT and all R is metal film 1% 1/4W
3-Way Electrical Switches How-To with Scott Shaeffer - San Juan Carpentry