Santa Barbara-based Sonos has been remarkably quiet over the years about how the company has been doing financially. However, the company disclosed Monday that it had $535M in revenue in 2013, nearly double the revenues the company had in 2012, making it one of the largest companies on the Central Coast. Sonos develops wireless, whole-home speakers, which can stream music from either a local PC or from across the Internet. Sonos is backed by BV Capital, Elevation Partner, Index Ventures, Kohlberg Kravis Roberts & Co., and Redpoint Ventures. The disclosure is sure to fan the rumors of a possible IPO filing for the company in the works.