Speaker introduction

This speaker is designed with reference to Harman Kardon glaze4,Support Bluetooth、USB、3.5Audio input,Using24V power supply,In order to ensure a simple appearance,The middle part is controlled by 6 touch buttons,You can connect to the speaker hotspot to enter the WEB management page for the speaker treble、bass、surround、Gain adjustment,The background supports Bluetooth modification configuration and light strip color and mode modification,Design uses tpa3116 as audio post-amp,NE5532 for amplification,tda7313 is used as audio adjustment, ESP32 transmits WiFi hotspots to adjust various configurations.

Production progress

2024-8-8 Completed the modeling of the speaker inner tank.
2024-8-10 Complete the overall modeling of the speaker.
2024-8-11 Completed the design of the speaker motherboard.
2024-8-14 The first generation of power amplifier motherboard welding and debugging.
2024-8-14 Speaker motherboard V1.0.1 design, mainly adding the upper and lower power anti-shock circuits.
2024-8-15 Complete all shell modeling.
2024-8-16 Printing the case.

2024-8-17 Optimize the power-on timing, solve the Bluetooth noise floor problem, and assemble the lower speaker rack and shell.

2024-8-31 Complete all shell printing, assembly and testing.

Continuously updated...

Bilibili updates the video simultaneously

[1:1 Hand rubbing Harman Kardon glass 4 speaker, -Bilibili] https://b23.tv/ovCPUOU

Code burning

The code is based on microPython, esp32 burns microPython and uploads the code to the root directory of the module to run, at present, the verification of each functional circuit is normal, the code is still doing the integration of light strips and web pages, and the first version can be auditioned demo.

Design Idea Diagram

Because of the size limitation of the free board, the motherboard has been split into two halves, and the middle part is connected by copper wire, which is convenient for students to proof, and the effect is as follows.

Note that the fan must be added for heat dissipation, otherwise the temperature will be very high, use the temperature control switch to control the fan to start.

Modeling effects and target effects

Finished product effect

The middle diffuser plate is modeled, the black lamp color change film is used to spray black, the connection is made of M2*5*4 brass soil eight hot melt nuts, and the M2*12 [6 heads * 0.5 thick] screws are used to fix with the middle shell.

Renderings of the model of the middle shell light strip mounting plate, the connection uses M3*8*5 brass soil eight hot melt nuts

The bottom speaker shell is equipped with 6 mid-high tweeters, a 7-inch bass in the lower part, and M3*8*5 brass earth eight hot melt nuts are used at the connection.

Bottom shell, wrapped with horn black mesh on the outside.

Model of the middle touch ring

5 bottom legs need to be printed and fixed in the corresponding slot of the shell using M3 15MM.

The interface housing is installed last and fixed in the corresponding hole of the housing using M3 8MM.

The acrylic cover is made of 15L acrylic trash can, cut in half, and glue is used to stick the gap with the light guide plate.

The background uses ESP32 to generate web page management, and the main functions are as shown in the following figure.

Main interface                                                                                                                                   

Audio configuration

Bluetooth configuration                                                                        

LED strip light configuration

Open-source protocol

The project is the first time it has been made public, and it is my original project.

This project follows the CC BY-NC-SA 4.0 open source license, and it is forbidden to reprint and commercialize without my authorization. Non-Commercial Use—ShareAlike 4.0 International License

Due to the lot of code logic, you can listen to the first version of the code first, and then update it continuously.