3 ms·

What about HDRadio? A home scale FM broadcast could accomplish this efficiently and cheaply. Each speaker would just need an FM receiver. I guess the downside

• cf100clunk 5y ago
  iBiquity (now owned by DTS) has never, to the best of my knowledge, open sourced their HDC codec, nor has it been reverse-engineered. To me that's a show-stopper towards any kind of widespread buy-in of HD Radio beyond commercial stations. Also, authorities like the FCC take a dim view of FM broadcasting beyond miniscule power levels as seen in car radio adapters due to the easy potential for intentional or unintentional abuse. For example, a 5 Watt FM transmitter sold on eBay may have you thinking it will yield a small amount of power, but spitballing some numbers: outputting it through an FM band turnstile antenna atop a high building or hill could have an Effective Radiated Power in the 7 or 8 kW range, great enough to cover a small city in a round pattern. Your proposed devices would therefore fall into that very low power range for certification but there would need to be some sort of clear channel hopping required. That's fine in rural areas but quite difficult in large metropolitan areas.