Audio enthusiasts with even more demanding tastes will be impressed by the AM/FM/XM/CD/MP3 audio system with touch-screen navigation that includes a 400-watt external amplifier, dedicated Dual Voice Coil (DVC) subwoofer, eight-channels and nine Infinity speakers available on the Limited. Infinity and Hyundai engineers worked together during the early stages of development to integrate the speakers into Hyundai Sonata's interior. The team spent hundreds of hours fine-tuning the system for the cabin's unique acoustic attributes.