Circuit Wiring Solution

The order of 4 or sealed rear chamber bandpass system is essentially a system of watertight enclosures with the addition of an acoustic filter for the driver. The resulting system usually provides a lower cut-off frequency, the compromise that a larger case. The space can be reduced by two drivers in isobaric configuration.

4th-order bandpass systems generally show better able to handle the functions that the other major systems are considered. The transient response and is second only to the sealed enclosure systems, making it a good choice for subwoofer applications.

Since all output 4th order bandpass system is via the port, the largest diameter possible for the port area should be used to minimize noise from the port. The ports must be incinerated where possible, for the same reasons.

The 4th order bandpass system rarely allows a perfect bandpass response - there is usually an out-of-band noise present in the production. A notch filter can be used simply to reduce the noise as audible. Otherwise, a lowpass filter used in series with the driver, but the in-band response system may be affected if this approach is taken.

As the speaker sound 4th order band pass issued by the openings or ports on the port side of the box, the port noise inevitable.

This unwanted noise can be minimized by a notch filter and the largest diameter possible for the port of the area should definitely be used. Another option is to burn the ports of the 4th order bandpass room as this will certainly help to reduce unwanted extra from the subwoofer.

This is the circuit diagram of USB powered computer speaker, or it widely known as multimedia speakers for PCs. The circuit has single-chipbased design, low-voltage electrical power supply, compatibility with USB power from computer, simple heat-sinking, inexpensive, large flexibility and wide temperature tolerance.

At the heart of the circuit is IC TDA2822M. This IC is, actually, monolithic type in 8-lead mini DIP (Dual Inline Package). It’s designed for use as a dual audio power amplifier in battery powered sound players. Features of TDA2822M are very low quiescent current, low crossover distortion, DC source voltage down to 1.8 volts and minimal output power of approximately 450 mW/channel with 4 ohm loudspeaker at 5V DC supply input.

An ideal power amplifier can be basically described as a circuit which can supply audio power into external loads without having producing substantial signal distortion and without having consuming extreme quiescent current.

This circuit is powered by 5V DC source obtainable from the USB port of the Computer. When electrical power switch S1 is turned to ‘on’ position, 5V power supply is extended towards the circuit and power indicator red LED1 illuminates immediately. Resistor R1 is actually a current surge limiter and capacitors C1 and C4 work as buffers.

How the circuit works..?

The operation of the circuit is very simple. Audio signals from the Computer audio port or headphone port are fed towards the amplifier circuit via R2 and C2 (for left channel), and R3 and C3 ( forright channel). Potensiometer VR1 used as the volume controller for left (L) channel, while potensiometer VR2 used to control the volume level of right (R) channel. Pin 7 of TDA2822M receives the left channel sound signals and pin 6 receives the right channel signals by way of VR1 and VR2, correspondingly. Amplified signals for driving the left and right loudspeakers can be obtained at pins 1 and pin 3 of IC1, correspondingly. Components R5 and C8, and R6 and C10 form the classic zobel network.

Construct the circuit on a medium size, general purpose PCB and enclose inside a appropriate case. It really is recommended to utilize a socket for IC TDA2822M. The external connections ought to be made working with suitably screened wires for improved result.

source: http://circuitdiagram.net/usb-powered-stereo-computer-speaker.html

Design simply what best fit the drivers capabilities while focusing on keeping the woofer in doing its job handling the bass, the mids handling the full midrange and so on. 500Hz and 4000Hz were chosen as the crossover frequencies. An L-pad circuit I felt was essential in keeping the response of the speaker perfect as possible. I didnt want anything to stick out. A schematic of the Hi-Vi 3 way crossover design is shown below.