The original Sonata was one of the first chassis to address the issue of noise. Besides a fascia overhaul, the third iteration isn’t vastly different, adding HD audio and eSATA outputs to the front, as well tweaks to the internal airflow.
Otherwise, the sound design remains: 0.8mm steel casework, a quiet (and 80 Plus-certified) 500W power supply, a tri-speed 120mm fan and grommets for reducing hard disk noise. The front and side panels have locks, and the case feels solid throughout, let down only by the cheap-looking frontage.
It’s an easy build, if slightly cramped, but the side-mounted hard disk bays and preinstalled PSU help enormously. The end noise result will depend on your GPU and CPU cooling, but this is a great foundation for an inexpensive silent system.