Simple Speaker-Flip Hack Gets a Little More Oomph out of the Adafruit STEMMA Speaker

Adafruit has shared a neat little hack for its popular STEMMA Speaker audio amplifier — boosting the volume considerably over the part as it is out of the package.

Designed for use with a range of microcontrollers, the Adafruit STEMMA Speaker combines a class D audio amplifier and small-format 1W 8 Ohm speaker with a STEMMA connector at one end and crocodile-clip-stroke-sew-pad connectors at the other. "Connecting it up is easy - you only need ground, 3 to 5V power, and audio signal," the company explains. "The audio signal does not need to be AC coupled, we do that for you, and can range up to the power pin voltage (3 or 5V peak-to-peak)."

Stock volume is adjustable using a potentiometer, but doesn't go particularly loud. For those who need a little more oomph — but with the proviso that it's still a very small 1W speaker, so it's never going to fill a room with ear-bursting sound — the company has released a simple modification.

"The speaker that's on here has adhesive on both sides and when it's installed at the factory it's installed face up," the company explains in a video demonstration. "Because that would make sense: You'd think you flip it face down or gonna sound muffled like this, right? But speakers are weird animals and sometimes what it's attached to or installed in becomes part of the resonant equation, and so if you peel off this other adhesive and flip the speaker over like this one here you get a little more oomph."

The modification is quick and easy, as shown in the video, and results in a noticeable improvement in volume — and without costing any money, nor requiring additional power to drive the speaker.