Case for Cheap USB/Bluetooth MP3/FM Player

This DIY project uses a cheap Mp3/FM player and two speakers to build a small soud system. The system is powered with one Li-ion rechargeable battery, connected to a TP4056 charger module; so it also works with an USB cable and a cell phone charger. The system uses a XL6009 step-up voltage regulator, to proportionate a steadier input voltage for the system. The suggested output voltage in the XL6009 should be 12V, but it may differ from a model to another. In the 5th picture above, its shown how I calibrated the output voltage in it. The player's case is a modification from this thing: https://www.thingiverse.com/thing:4942179 . The speaker's case is also available here: https://www.thingiverse.com/thing:7291429 . Parts Needed 2x 3W rectangular speakers - 65mm x 35 mm (2.56" x 1.38"). See pictures above. 1x cheap MP3 Bluetooth FM player (with amplifyers) - small version. Easily found on AliExpres (and in many other gadget stores). 1x Li-Ion (or Li-Po) lithium battery. 1x TP4056 charger for lithium batteries. 1x XL6009 step-up voltage regulator. 1x KCD10-101 rocker switch (20mm x 15mm). 10x screws. Wires. Double-sided tape. Printed Parts: Speaker1e3b8Inch_3W_01.stl x2. Speaker1e3b8Inch_3W_02.stl x2. MainBox_01_Main.stl x1. MainBox_02_Lid.stl x1. Print Settings: Printer: Creality Ender-3 V3 KE Filament Material: PLA Resolution: 0.3 Infill: 40% Infill Pattern: Tri-Hexagon Rafts: No Supports: Yes