Low pass filter for Subwoofer Circuit

The application that we propose is a simple filter that limits the acoustic region (20-20000Hz) to the region 20-100Hz. With the manufacture proposed, an active filter can be created to drive a loudspeaker for very low frequencies. This allows for the placement of a larger speaker alongside the Hi-Fi speakers. To achieve a complete sound experience, a corresponding amplifier will also be required. The circuit input will connect to the two outputs of a preamplifier or the line output of a preamplifier. The manufactured circuit allocates an output to drive a subwoofer circuit. If space does not permit the placement of a third speaker in the listening area, a smaller speaker can be selected. The output will depend on the type of music played.

In the schematic, three different circuits primarily revolve around two operational amplifiers. These circuits constitute a mixed amplifier with variable gain and a variable filter. The final design requires a power supply with an operational tendency of 12V. The operational amplifiers used in these circuits are of the dual operational type, such as the TL082 and NE5532. These operational amplifiers belong to a family equipped with field-effect transistors (FET) at their inputs. Each member of this family incorporates both bipolar transistors and field-effect transistors. These circuits can operate at high voltages due to the use of high-voltage transistors. They also possess a high slew rate, low input bias current, and are minimally affected by temperature variations. The operational amplifiers have a unity gain bandwidth of 3MHz. Another important selection criterion is their high noise rejection, which exceeds 80dB, with a low current consumption ranging from 11 to 3 mA.

The operational amplifiers are available in an 8-pin package containing two operational amplifiers, and in a 14-pin package containing four operational amplifiers. They are marketed under codes such as TL074, TL084, and TL064, while the 8-pin operational amplifiers include TL061, TL071, and TL081. In this design, the TL082, which contains two operational amplifiers, is utilized. The first operational amplifier from the TL082 functions as an amplifier and mixer for the two channels. Its negative input features a small mixer with two resistors. A potentiometer in this configuration determines the circuit gain. At this point, the left and right channels of the preamplifier are combined through two resistors. The operational amplifier strengthens the signal with gain dependent on the potentiometer setting.

The position of the potentiometer is proportional to the circuit gain. The second operational amplifier serves as the filter. This filter is an acoustic low-pass filter designed with components surrounding the operational amplifier. It is a second-order low-pass filter with a variable cutoff frequency. This frequency can be adjusted to range from very low frequencies of 30Hz to exceeding 150Hz.The application that to you we propose is a simple filter of region that limits the acoustic region (20-20000Hz) in the region 20-100Hz. With the manufacture that to you we propose you can make a active filter in order to you lead a loudspeaker of very low frequencies.

With this you will place one bigger speaker between the HIFI speakers of you. In order to you have a complete picture of sound you will need also the corresponding amplifier. In the entry of circuit you will connect the two exits of preamplifier or the exit of line of some preamplifier. The circuit of manufacture allocates a exit in order to is led means of circuit of force subwoofer. If for some reason you do not have space in order to you place the third speaker in space of hearing, then you can select smaller speaker.

The output will depend from the type of music that you hear. In the form it appears the theoretical circuit of filter. In first glance we see three different circuits that are mainly manufactured round two operational amplifiers. This circuits constitute mixed, amplifier with variable aid and a variable filter. The manufacture end needs a circuit of catering with operational tendency of catering equal with 12. the operational amplifiers that constitute the active elements for this circuits of are double operational type as the TL082 and NE5532.

The operational these amplifiers belong in a family provided with transistor of effect of field IFET in their entries. Each member of family allocates in their circuit bipolar transistor and effect of field. This circuits can function in his high tendency, because that they use transistor of high tendency. Also they have high honor of rhythm of elevation (slew rate), low current of polarization for the entries and are influenced little by the temperature.

The operational these amplifiers have breadth of area unity gain bandwidth 3MHz. A other important element for their choice is the big reject of noise, when this exists in the line of catering. The price of reject is bigger than 80dB, their consumption is small, from 11 until 3 mA. They are internally sold in nutshell with eight pins and allocate two operational amplifiers, In the same line in nutshell 14 pins they incorporate four operational, In the trade they are sold with code TL074, TL084 and TL064, In nutshell with eight pins they are sold operational amplifiers TL061 TL071 kajTL081.

In the manufacture we used the TL082 that has two operational. First operational from the TL082 it works as amplifier and mixed for the two channels, In his negative entry he exists one small mixed with two resistances. A potentiometer in this rung determines the aid of circuit. In the point this left winger and the right channel of preamplifier they are added means of two resistances.

En continuity the operational strengthens signal with aid made dependent from the price that has the potentiometer. The place of runner is proportional with the aid of circuit. The second operational amplifier is the filter of manufacture. The filter of is acoustic frequency of second class and he is made with the materials that are round the operational amplifier.

The filter of is low passage with variable frequency of cutting off. This frequency can be altered and take prices from very low frequency the 30Hz or still exceed 150Hz. 🔗 External reference