I'm using this module based on the popular bluetooth module CSR8635 https://www.tinyosshop.com/index.php?route=product/product&product_id=875
I was wondering why, in the right-hand side of the circuit, there are two capacitors before the speaker.
In building this circuit, I have found that leaving out these capacitors result in no sound whatsoever. Tinier capacitors give less sound while higher valued capacitors give more sound. In fact, it seems the audio quality also rises with the size of the capacitor? Why is this?
Why does the audio signal become more "intelligible" after the capacitor? How does the capacitor value affect the frequencies that resonate inside the speaker? Shouldn't the capacitor act as a LPF and filter out any high frequencies?