I have a PAM8403-based amplifier module and am going to build a small portable speaker, mostly to listen to lectures and audio books. The module looks like this:
First I attached two 4 ohm 3 watt speakers and it worked fine. But I've read that it would make a clearer sound with 8 ohm speakers. And in the module properties it says it can work with 4-8 ohm speakers.
A clear sound would be a benefit for me, but will I lose power (loudness) with higher resistance speakers?
How is the sound quality related to the speaker resistance? What is the theory behind it?
All the speakers I am going to use would be the same diameter.
Here is the efficiency chart from the PAM8403 datasheet:
As far as I know, efficiency is about delivered power, not quality of the sound. Please correct me if I am wrong.