DIY a mini audio equalizer

project description: The item's mini audio equalizer can connect audio sources such as laptops and a pair of speakers. It allows users to use the following three instruments to adjust the sound of audio 1.) Use three-band equalizer to zoom in or attenuated low, medium and high-range tones. 2.) Use a dynamic range compressor to eliminate any sudden changes in volume 3.) Use the amplifier to enhance any quiet signal source. This project originated from another 3-band equalizer I made a year ago. I have received my friends, so I decided to make another transformation and upgrade. Project details: The general problem solved by this mini audio equalizer is: the volume of the audio source is unstable; there is too much power in one area of ​​the audio spectrum; the speaker has a non-flat response; in order to make the product easy to use while maintaining the product, The following design specifications must be met: Use the battery to power Using low price equipment Can be installed in a common rubber roller housing Use the carefully selected central frequency and Q factor to select a equalizer in the common frequency in the music. The compressor has a sufficiently high ratio to eliminate noise spikes from microphone matte or feedback, television advertisements, loud and soft radio channels. Set the primary volume knob to make it easy to set the output volume or increase the mute input signal. compressor: In order to make the compressor work properly, the amplitude of the input signal must be set correctly. The input and output amplitude data chart of the compressor: As you can see, there is an area related to the input and output amplitude. There is also a zone, in which the input amplitude can vary wide, but the output amplitude is almost unchanged. These linear and plateau areas are the root cause of the input source amplitude must be correctly adjusted; When you are listening to an audio signal, you must never want the compressor to a certain level, unless you have a lot of noise. What you want is the linear relationship between the input and output amplitude and a constant gain. It is desirable that the circuit works in the linear area. The circuit will enter the plateau area only when a large signal that needs to be compressed. In the actual design, ideally, the trigger of the indicator light is based on the voltage (Q1 of Q1) based on the determining the compressor gain, as this is the parameter that determines the linear or nonlinearity of the circuit. Since the basic voltage of Q1 changes a few millivitis between the beginning of the linear area and the end of the plateau area, I chose to build my indicator on the input amplitude.

Our other product:

Professional lightning protection system for Tower	Professional FM Radio Station Equipment Package	FMUSER FU-1000C 1000W FM Transmitter With USB Audio Input Interface
FMUSER 200W FM Radio Broadcasting Package	Hotel IPTV Solution	FMUSER FSN-1000T V5.0 1KW FM Radio Broadcast Transmitter