Speed of Sound Audio Experts delivers a professional Harley GTS radio audio upgrade focused on clean volume, clarity, and factory EQ correction. This build covers 2019–2023 Harley GTS stereo upgrades, Apple CarPlay activation, TechnoResearch radio flash, and distortion tuning. Featuring Ground Zero Neo 6.5 speakers and ARC Audio Moto 720 amplifier installs, we provide proven motorcycle audio upgrades across New Hampshire.