Rudolf Stember is the audio director at Factor 5 and a composer of numerous Amiga and Commodore 64 titles. Born in Cologne, Germany in 1969, a turning point in his life was when he got a Commodore 64 in 1984.  He started to make music using the computer for his own enjoyment in 1986 and was soon asked to make music and sound effects for computer and video games. Following his debut The Tower of Terror, he worked on numerous Commodore 64 and Amiga titles for Cyberstyle such as Orbit, The Curse of RA, and Ramses. He quickly gained a reputation as a master melodist and versatile sound designer so was recruited to work on numerous other projects such as B.C. Kid and Mr. Nutz. This put him on course to featuring in over 100 game credits since 1989.

Ever since his involvement in Z-Out, Stember has been friends with Chris Hülsbeck. Despite both composers usually working alone on their respective projects, they have occasionally worked together on titles such as The Secret of Monkey Island, Metal Law, and Mad News. Stember also made guest appearances as a composer and arranger on  Hülsbeck's popular album releases Shades, To Be On Top, and Rainbows.  Stember in turn invited Hülsbeck to offer a bonus track for the album release of the epic score to the well-known Blade of Destiny. Although Stember has often lived in the shadow of  Hülsbeck's popularity, he is similarly esteemed among game developers and hardcore Amiga fans.

Following the decline of the Amiga, Stember turned his attention to other games. He became familiar with the PC through working on numerous Amiga ports and several obscure original titles. Simultaneously he developed expertise as a voice editor in German and English on various other PC titles. He also worked closely with Factor 5 composing the Super Nintendo's Indiana Jones: Greatest Adventures and converting the music for the Game Boy's Animaniacs and Probobector II. He decided to join the company when they moved to San Francisco, California in 1996 and was appointed audio director. Though he no longer composes music, he has had sound design, voice editing, and direction roles on the Star Wars: Rogue Squadron series, Indiana Jones and the Infernal Machine,  and Lair alongside Chris Hülsbeck.

Stember has proved to be a multitalented artist throughout his career. On the early game projects Blutrausch and Decton, he was also involved in art and programming roles. In further music roles, he has scored and mastered several German television series and produced a remix for a recently published Elvis Presley tribute album. He also continues to offer tributes to his Amiga past, having produced a Z-Out remix for Immortal 2 and offered all his early music for download on his personal website. In a further testament to his importance during the Amiga years, Stember was asked to contribute to the Merregnon trilogy alongside various demoscene musicians. During his hours away from Factor 5, Stember has further demonstrated his artistic flair producing impressive photography and website design, some of which can be seen on Hülsbeck's latest album Number Nine. In 2008, Stember left Factor 5 when it closed due to financial difficulties. His next destination is unclear.