I'm currently working on a 3rd version of a project. Bicycle lighting for emergency services. (for two wheel pedal bikes) I'm using an Arduino nano, and neopixels along with custom PCB's all powered from a 3.7v 10AH battery.
With this new version I've added:
25w 2.5" Sony speaker
The amplifier is OEP30w (mono version)
10k potentiometer attached to control the volume, this is place before the audio input to the amplifier
audio is from the adafruit mini FX 16mb version.
I'm using 2 sounds - siren and horn
For power From the battery I have a step up converter that steps up 3.7v to 5v for the audio board and Arduino nano. The amplifier is connecter to a step up converter that goes from 3.7v to 16v
When I go past ~75% volume the system starts to glitch- LED's on the nano and audio board flicker, neopixels will go to random colors, if the volume is turned up too much it will cause the system to completely stop working. I then have to reconnect the audio board to the computer for windows to "fix this drive" and re-upload my code to the Arduino nano.
The 5v rail has a 1000uF capacitor right near the main input (this capacitor is near the volume pot (not sure if this will cause interference) there are no capacitors on the 16v side.
The other issue I have is that if the volume is set to "zero" I have a higher pitch sound coming from the speaker, the sound is less noticeable when the volume is turned up.
any thoughts on getting the system to work right would be appreciated.
Having added 18AWG wire from the 16v supply directly to the amp (there was a pcb trace going to it) and adding 18AWG wire from the amp to the speakers, has limit all noticeable standby static. I still however at larger volume levels have the LED's blinking on the nano / audio board; which if the volume is too high the boards need to be re-programmed. I might end up scrapping the volume potentiometer and just add a resistor at a value that wont trigger the fault but allow for the loudest volume. I also cut the ground connection for the volume potentiometer, which has cleared even more static but now wont allow for the volume to be turned off, wondering if I need to add solid wire for the audio connection as well.
Might try some capacitors across the speaker.
Thanks for the suggestion of add the wires. might try larger AWG but Don't think it will make that much more of a difference at this point.
Below ling is the PCB I've designed and is what all the parts are currently connected to.
And the schematic view for the PCB
I've also changed my siren Audio file (it was the one causing the most power issues) and it seems to function better, might actually be usable but I'd still be interested in knowing why I can't have full volume
