In late 2011 SPL was approached by Sennheiser Professional Division to design and to manufacture a stereo to 5.1 surround controller for broadcast applications.
SPL developed a 1U/19" rack-mount unit with an high-grade dual channel microphone preamplifier and a DSP boards on which the stereo input is being changed into a 5.1 surround signal by using a software designed by Illusonic of Switzerland.
Development partner on the DSP boards was the German company BayerDSP from Duesseldorf.
With Esfera it becomes very easy to broadcast surround sound audio. Existing stereo miking can further be used. Esfera creates the surround sound thereof.