BOSE: Are the Bose 901 speakers still considered among the best?

Eric Huang replies ....

I’m not an audio equipment expert. But I can share some things I learned about the Bose 901 speaker from the man himself, because I took Professor Bose’s acoustics class when I was undergraduate, and we got to ask him lots of questions.

When people buy speakers, what sounds “best” is extremely subjective. For example, Prof. Bose told us about a consumer research study he did where regular people (not studio engineers or musicians) listened to music and adjusted some equalizer knobs until it sounded best to them. Most of the people actually adjusted the equalization spectrum so that the sound reproduction did not have much bass. That is because the most common place for people to listen to music is in their car, and car speakers of the time had extremely poor bass reproduction. This is what they were used to when they were “enjoying” music.

Bose noted that one of the characteristics that people enjoy most in reproduced music is “warmth/depth”. There are a number of things that go into the sound being “warm/deep.” One of the most important, though, is reflected sound. The major “difference” between the Bose 901 and all other speakers before it was that the majority of the sound is directed away from the front so that sound has to reflect off the wall and other surfaces before it reaches the listener. Thus, Bose 901 speakers produce “direct + reflected” sound with a majority of the sound being reflected.

The problem in a home listening environment, though, is that most people don’t control for the characteristics of their room. They might have a hard object, like a brick wall, behind the speaker. With the 901 projecting sound rear-ward, this will result in a “harsh” sound instead of warm one, because of the “hard” reflections causing persistent resonant frequencies. That’s why so many people say Bose 901s sounded bad when they tried them in their home.

If you go to an audiophile’s home, you will notice that their “listening room” usually has acoustic panels and is carpeted. These features act as sound filters, and in effect, “warms up” reflected sound. This is an ideal environment for the Bose 901 speaker since it produces so much reflected sound.

Bose’s marketing people made sure that the 901 speaker was demonstrated by sales people in listening rooms with acoustic treatments in high-end audio stores. Compared to other high-end speakers that produce only sound directed at the listener, the 901s sounded much better. Hence, they were a huge commercial success.

In his class, Prof. Bose gave us a clue as to how he discovered that reflected sound makes speakers sound warm: electrostatic speakers. Electrostatic speakers are extremely expensive to manufacture, and extremely inefficient. A pair by Martin Logans usually costs over 2000USD. Why are audiophiles willing to spend so much on them? It turns out, one of the interesting characteristics of electrostatic speakers is that they usually don’t have an enclosure like conventional “box” speakers. So, like the 901 speakers, a lot of the sound that an electrostatic speaker produces is actually projected behind the speaker instead of at the listener. This results in the listener getting a nice warm, deep mixture of direct+reflected sound with electrostatic speakers. Essentially, Bose was able to replicate this sound using conventional speaker technology with the 901s.

Back to the original question - are Bose 901 speakers still considered to be among the best? My answer: it doesn’t matter what the “experts” say, because they don’t live in your home. The “best” speakers in a lab will not be the best speakers in a listening room. The best speakers in a listening room will not be the best speakers in your living room. The important thing is to find some speakers that you enjoy listening to and that fit your budget and lifestyle. And the only way is to try them out in your home, not in the electronics store.


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