When Porsche optimizes a vehicle, no component is truly safe from the relentless search for weight reduction. We are accustomed to seeing carbon-fiber body panels, magnesium wheels, and thin glass on the most go-faster models in the lineup. But now, the Zuffenhausen-based manufacturer has turned its engineering focus toward an unlikely culprit.
Porsche and Burmester have unveiled the world’s first production-ready automotive stereo with gallium nitride semiconductor technology. Developed for the Burmester 3D High-End Surround Sound System, this architecture replaces traditional silicon transistors, delivering higher electrical efficiency and power density from a lighter amplifier package.
Gallium nitride has spent years revolutionizing aerospace satellites, smartphone chargers, and laptop bricks. Its arrival in automotive audio marks a first for the industry, and to understand why Porsche cares about the semiconductor industry, one must look at how amps operate.
Conventional automotive sound amplifiers rely on silicon-based transistors for voltage conversion. Silicon switches, however, generate substantial thermal energy during operation. Wasted heat demands heavy cooling apertures, which are often made from aluminum, in turn adding unwanted mass to the vehicle. This is where gallium nitride makes a world of difference.
GaN allows the switching transistors to operate at higher frequencies with significantly lower losses than equivalent silicon componentry. Because energy transfer becomes dramatically more efficient, less electricity converts into waste heat. The Porsche x Burmester project kicked off in 2023, when Porsche decided to explore whether GaN could survive the demands of the automotive industry.
Photo: Porsche
By the spring of 2024, the audio, semiconductor, and sustainability specialists at Porsche partnered with the folks at the Institute for Robust Power Semiconductor Systems at the University of Stuttgart to build a functional prototype. Working alongside a chip manufacturer and Burmester, the team successfully engineered a GaN chip dedicated to the voltage conversion stage of a 400-watt sub amp.
The payoffs of this chemical shift are tangible. Because the gallium nitride-based subwoofer amplifier generates less heat during heavy operation, the team was able to shrink the aluminum heat sink by 20 percent. Furthermore, elevated switching frequencies allow passive electronic components (think capacitors and inductors) to be downsized accordingly, resulting in a lighter and smaller amp module.
This, in turn, frees up vital cabin space without surrendering a watt of acoustic punch. There is a green fringe benefit to shedding metal as well because aluminum smelting is an energy-intensive process. Reducing the raw aluminum volume needed for each heat sink directly reduces CO2 emissions during the manufacturing stage.
Going forward, the subwoofer is merely the proving ground for a broader audio revolution. Gallium nitride’s potential may extend to pretty much every single automotive onboard system where power conversion occurs, including power conversion in high-voltage systems.
GaN, therefore, is particularly promising for the high-voltage systems of upcoming all-electric Porkers. While this hardware debuts inside a high-end audio system, its true value lies in serving future battery-electric and gasoline-electric Porsche models.