Sonos was certainly one of the first companies to simplify the operation of multi room audio and it seems that they may have a patent or two to prove that.  Recently Sonos took Denon to court and has won a partial victory against their owners.

Sonos has won a partial judgement against D&M Holdings, the owner of Denon, concerning patent infringements relating to their multi-room audio products.

They brought the lawsuit back in 2014, alleging that the "manufacture, distribution, and/or sale of the HEOS system infringes a number of Sonos patents related to wireless audio products".

The lawsuit concerned a total of 12 patents relating to control and operation of multi-room systems, which Sonos claimed Denon's HEOS speakers infringed.

Last year, D&M Holdings moved for a partial judgement on four of the patents, which the company claimed were "directed to ineligible subject matter". These four patents broadly related to volume control and the method of grouping multi-room speakers together.

This week a US court ruled against D&M Holdings, citing Section 101 of the Patent Act, which says: "Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title."

The court ruled that the patents did not cover "abstract ideas" and were eligible for patent protection.

http://www.whathifi.com/news/sonos-wins-patent-ruling-in-denon-lawsuit