We don’t often think about reflected sound, but a man name Amar Bose did when he set the audio world on its ear. Pun intended.
When we look at a pair of speakers sitting in our living room we imagine the sound comes straight from them and arrives at our ears unscathed. Nothing could be further from the truth. Sources of sound broadcast in pressure waves that expand into the room as they travel. Lower frequencies like those from a bass guitar or the tall throat of a pipe organ have waves measured in many feet, while higher frequencies, like those from cymbals and drum whacks, produce waves in the inches. Sound waves broadcast into your living room in the shape of a horizontal cone, bouncing off any surface the pressure waves strike: walls, ceilings, floor, and furniture. These delayed sound waves are what we call reflections.
Bose built speakers that took advantage of these reflections. Their first model, the 2201, was shaped like an eighth of a sphere so that it could be tucked into the corner of a room. Its 22 tiny speaker drivers projected sounds in various directions-some directly at the listener, like normal speakers, and some toward reflective surfaces like walls and the floor. It was a new concept but a commercial failure—Bose sold fewer than 300 pairs, the bulk of production winding up in a landfill. Then came the 2201’s successor, the 901.
The 901 was based on many of the principles used in the 2201, and featured 9 identical small woofers: eight firing to the rear and one pointing at the listener. By this arrangement of drivers, the 901 bounced sound off the walls behind the speakers. Imagine turning your home speakers around so that their drivers face the wall. This made the Bose 901 sound big, spacious, and “live” with all music-even music that hadn’t been recorded that way. The 901’s big sound impressed the hell out of early stereo buyers, and they sold like hotcakes.
I make fun of the 901, something I shouldn’t do because that speaker was in every sense of the word a seminal product. The Bose 901 changed the way we think about sound reproduction and that, my friends, is a very good thing. I’ve put together a video on the subject which you can watch, here.