I don't know if they still do it, but for a number of years Yamaha's multichannel amplifiers had provisions for front surround speakers that were to be placed outside and above the main front speakers. It can offer a very open and spacious soundfield when used with their processors. (Remember, Yamaha has been a major player for decades in pro audio reverbs and effects processing.)
A curious multichannel effect
Every so often we stumble over an unusual audio effect. I am building a large pool room that is connected to my house via another large room. The connecting room has two large door openings into my living room which is where the audio system is located. While working on this addition I pulled my Maggies over in front of the door openings and played some music. It was Multichannel. So the situation was a roughly 70 foot "room" with the Maggies (Front) half way (35 feet) and the Rear speakers BEHIND the front speakers by about 35 feet. For orchestral music, where the rear channels are ambience (not distinct instruments) the effect was stunning. I wonder if similar results might be obtained using "rear" speakers located in the front of the room with their signals delayed by the equivalent of 70 feet.
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