For Gerald Stephens, a registered nurse from Houston, TX, music isn't just background noise—it’s a full-blown experience, and now, it rides with him wherever he goes.
What started as a simple frustration during his weekly group bike rides turned into a DIY audio revolution on wheels. In Houston’s cycling community, it's common to see homemade speaker trailers blasting music from car audio setups. They’re loud, sure—but they lack clarity. And Gerald, armed with only a store-bought Bluetooth speaker, found his music drowned out. That’s when the real engineering began.
From Problem to Passion: Building a Better Bike Sound System
"I saw a few examples of homemade speakers using military ammo boxes,” Gerald recalls. Intrigued, he set off experimenting with various chip amps, looking for the perfect balance of power and fidelity."
His research led him to the TPA3255 chip—a powerhouse known for delivering high performance in a small form factor. From there, it didn’t take long before Fosi Audio came into the picture.
“Of course, I researched who was making the best TPA3255 amps and that brought me to Fosi Audio. My first build using the BT20A Pro blew me away—not only was it incredibly loud, it sounded great.”
Word spread fast. Gerald’s setup didn’t just turn heads—it turned up the volume with clarity and consistency. “People always ask what’s inside the can. They’re amazed that something so compact can put out so much clean sound.”
The Secret Sauce: Custom Batteries Meet BT20A Pro
Gerald's not just an audio enthusiast—he’s also a battery builder. His custom 12s lithium battery packs deliver a rock-solid 48V with up to 30 amps of continuous output. That means his BT20A Pro isn’t just performing—it’s thriving.
“I’ve seen tests of your amps on YouTube with standard 5 or 10 amp power supplies. But my batteries give the amp everything it needs—and it shows.”
These aren't lab conditions, either. Gerald's sound systems endure Texas heat, long ride hours, physical bumps, and still hold up to the challenge.
Beyond the Bike: Coolers, Custom Builds, and Burning Man
What started as a personal project quickly evolved into a passion Gerald shares with friends. He’s built custom sound systems for others—including one of his more unusual builds: a Coleman cooler converted into a full-on speaker box, powered by a BT20A Pro and loaded with 4 x 6.5” pro audio speakers and 4 compression tweeters.
And the crown jewel? His setup made it all the way to Burning Man, one of the world’s most sound-competitive festivals.
“I took my speaker to Burning Man, and I was as loud as some of the Art Cars on the Playa with professional sound systems.”
Built to Blast. Built to Last.
Gerald’s story reminds us why we do what we do. At Fosi Audio, we design compact, high-performance amps that empower creators, innovators, and music lovers around the world.
Whether it’s a high-end home setup, a DIY cooler build, or an e-bike turned into a mobile dance floor, we’re proud to be part of the soundtrack to your adventures.
Thank you, Gerald, for trusting Fosi Audio. Ride on.