3 Way Crossover -24dB

The circuit is a classic electronic crossover circuit. It serves as a passive crossover circuit found in all three-way loudspeakers. The difference is that each loudspeaker uses a separate final amplifier. Thus, for a three-way loudspeaker setup, six final amplifiers are required. This configuration has the drawbacks of increased cost and space occupied by the additional amplifiers. However, the quality of sound reproduction improves significantly, and regulating parameters for each loudspeaker becomes much easier and technically feasible. In this particular circuit, the signal emanating from the preamplifier output is applied to the IN, and the total level is regulated via RV1.

The IC1 provides input adaptation and circuit isolation. IC2A-B and the surrounding components form a high-pass filter with a slope of -24dB/oct, with a crossover frequency (fc) of 3100 Hz, driving the high-frequency loudspeaker. The IC2C-D (high pass) and IC3A-B (low pass), along with their associated components, create a band-pass filter with a slope of -24dB/oct, at crossover frequencies of 400 Hz and 3100 Hz, respectively, driving the mid-range loudspeaker. Finally, the IC3C-D shapes a low-pass filter with a slope of -24dB/oct, which drives the low-frequency loudspeaker. The levels to the amplifiers can be adjusted using trimmers TR1-2-3. The crossover frequencies can be modified based on the characteristics of the loudspeakers used; calculations for a -24 dB/oct crossover can be applied. All resistors should be metal film with a tolerance of 1% and rated for 1/4W, while capacitors should be as close to the theoretical values as possible, preferably polypropylene, mylar, or MKT types. It is intended to build such a circuit for each channel.

R1 = 10K ohms, TR1-2-3 = 10K ohms trimmer, C18 = 680nF 63V MKT
R2-4-10 = 11K ohms (22K//22K), C1 = 4.7uF 63V MKT, C19-21 = 3.3nF 63V*
R3-5 = 22K ohms, C2-3-4-7 = 100nF 63V ceramic, C22-24 = 20nF 63V (10//10nF)*
R6-8-14 = 28K ohms (56K//56K), C5-6-8-9 = 3.3nF 63V*, C23-25 = 10nF 63V*
R7-9 = 56K ohms, C10 = 220nF 63V*, C26 = 2.2uF 63V MKT
R11-12-13 = 11K ohms (22K//22K), C11-12-13-14 = 10nF 63V*, IC1-2 = TL074
R15-16-17 = 28K ohms (56K//56K), C15-17 = 6.6nF 63V (3.3//3.3nF)*, IC3 = TL071
RV1 = 47K ohms Log., C16-20 = 100nF 63V MKT, C* is polycarbonate, polypropylene, MKT, and all R is metal film 1% 1/4W.

The circuit's design emphasizes the importance of selecting high-quality components to ensure optimal performance and reliability in audio applications. The use of operational amplifiers like the TL074 and TL071 enhances signal integrity and minimizes distortion, critical for high-fidelity audio reproduction. The careful arrangement of filters allows for precise control over frequency distribution, ensuring that each loudspeaker operates within its optimal range. The flexibility to adjust crossover frequencies provides adaptability for various speaker configurations, making this circuit a versatile solution for audio enthusiasts and professionals alike.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 🔗 External reference