Bose 901

OLYMPUS DIGITAL CAMERAThe story of this decidedly peculiar product started when Armar G Bose decided that contemporary loudspeakers simply didn’t deliver. Fascinated by sound propagation, and an avowed fan of spatiality in sound, he thought the majority of designs on sale were too directional. He believed that a ‘pulsating sphere’ was the perfect shape to produce sound, but knew that this was not a practical domestic proposition.

The Bose 901 Direct/Reflecting loudspeaker was the result. Launched in 1968, it was a radically different design. No less than nine drive units were used, all of which except one point rearwards. Diametrically opposed to the thinking of the day (and indeed now), no crossovers were used – not least because of the ensuing phase distortion which mars time-domain accuracy. The intention was to give a single mix of direct and reflected sound.

The design had various interesting characteristics. With an array of under-stressed drive units, there was plenty of dynamic headroom, and no sense of the sound being squeezed through a toothpaste tube. It gave relatively low distortion as a result, and reasonable low frequency articulation. However, there were no bespoke tweeters fitted, so the high frequencies sounded recessed, and the small diameter of the many drivers meant that handling of low bass was a bit curtailed too.

The solution was to make them partially active; to boost the low and high frequencies, by the simple expedient of an electronic equaliser that used the tape monitor loop of an integrated amplifier or preamplifier. The worked, but only when there was enough power on tap. With nine voice coils to heat, the Bose needed a lot of power – at a time when it was very much at premium. As a result, the first 901s sounded open, expansive and detailed, but only if you had the amp to drive it – and not many did! Fortunately for the 901, history’s direction of travel went in its favour. First, power amplifiers got more muscular, and cheaper too. At the same time, Bose refined the 901 to iron out its issues. The Helical Voice Coil on the 901/III was a big moment, being far more sensitive than earlier 901 drivers.

Whilst technology moved on to help the 901, fashion didn’t. By this time stereo was all the rage and buyers wanted speakers that gave pin-point imaging, rather than just a ‘wall of sound’. The 901 would have been great in the days when a speaker’s lot in life was to fill the room with music, but by the late nineteen seventies it was supposed to follow Phil Collins pan rolls across the speakers from left to right. Trouble was, the big Bose just wasn’t accurate enough at this; its whole raison d’être was to radiate sound rather than beam it from a single point sound.

These days, Bose 901s remain fascinating speakers, and ironically are easier to use than before thanks to the profusion of good, inexpensive transistor amplifiers. Then again, people’s homes are getting smaller, and that doesn’t bode well. If you have a largish and fairly symmetrical listening room, and are looking for a more ambient listening experience – as opposed to a forensic, analytical one – then you may love them. They sound like nothing else around, with a wonderfully coherent, seamless and expansive nature. But still, because of the lack of crossovers and the fact that they’re effectively an array of midrange drivers, you get a very upfront and direct sound.

Now in its sixth generation and selling for £1,799, the latest version has over 350 improvements over the originals, both cosmetically and sonically. Fascinatingly, the 901 must have one of the longest lifespans of any loudspeaker in history. It continues to sell because people like it, and feel it offers something quite unique. Whilst some audiophiles might be sniffy about the Bose brand, this shouldn’t be overlooked.

One comment

  1. This is a very fair assessment of the bose sound phenomenon.

    There has been SO much controversy regarding the 901s because of the flawed design concept. Yeah,that’s me being biased. The 9:1 ratio happens at microphone except in an anechoic chamber.

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