The original sound system in this Porsche Targa 4S was the so-called "premium" BOSE system. While it does sound better than the standard setup, any music enthusiast or professional immediately recognizes that this system lacks dynamic range, clarity, and bass depth. Plus most 911 models have the annoying door card rattles problem. It’s clear that corners were cut in its design.

We were tasked with upgrading this system to deliver truly amazing sound — and with no budget restrictions, the goal was simply to create a world-class audio experience for everyday driving.

Our approach always starts with seamless integration. We design sound systems so that there are absolutely no visible changes to the car. This time, we pushed that philosophy even further — achieving incredible sound quality without adding any external or custom subwoofers.

Unlike older 911 models with space in the "frunk" or under seats for extra amplifiers, DSPs and other accessories, the Targa 4S offers no such room, making this upgrade even more challenging. 

We chose to use a mObridge MOST to optical converter primarily to deliver pure, high-quality digital sound directly to our main amplifier and DSP. This setup allows us to completely remove the original BOSE amplifier and repurpose its location to mount our main amplifier—an essential consideration given the limited space available in this car 

We have chosen the top of the range Helix i7 speakers for this installation as they offer exceptional sound and they fit perfectly in the original speaker locations thanks to the FlexMount accessories that can be purchased separately. This means these speakers can be used seamlessly in a wide range of cars such as BMW, Mercedes-Benz, Porsche, Tesla and more.

Because we decided to use the Helix i7 woofers as subwoofers, we applied a 6-layer high-quality soundproofing material to the doors. This treatment eliminates vibrations, fully isolates the doors, and effectively turns them into sealed enclosures, enhancing bass performance and overall sound quality. 

The HELIX P SIX DSP ULTIMATE amplifier is powering all 6 speakers in full active mode meaning every single speaker has its own dedicated channel, allowing us to tune each speaker individually for immaculate and precise sound.

As we often emphasize, the rear stage is less critical than the front in achieving an immersive sound experience. Therefore, we chose to retain the factory rear speakers without replacement. However, to elevate the overall staging and equalization—and to utilize four spare Helix DSP outputs, we integrated the new 4-channel ETON MA4 amplifier. It is compact yet powerful and with its four channels it makes the whole system a 10 channel active setup.