Bose 901 Series VI Review

Bose has been building a speaker for 45 years that seems to turn conventional wisdom on its head. Does hi-fi history need to be rewritten? Or is the legendary 901 just a clever design?

When NASA set out to conquer the moon, Bose founder and namesake Amar Bose, who was already allowed to study at the renowned Massachusetts Institute of Technology as a 17-year-old, developed a loudspeaker that seemed to be built contrary to all the usual rules. So it was with nine broadband Loudspeakers, eight of which radiate from the back against the listening room wall.

If you look at where Bose’s idea came from, it seems less eccentric since he was concerned with the psychoacoustics of concert halls. But, in fact, the direct sound component of the instruments in a concert only makes up a comparatively small part of the sound energy that reaches the listener. By far, the most sound reaches the ear via many reflections from the room.

Rearview: The transparent model shows the internal structure, which has remained the same for decades, with eight rear full-range speakers and bass reflex plus a chassis to the front.

PROS:

• Amazingly deep, powerful bass.
• Easily adaptable to the listening room using standard EQ
• Sounds spacious and powerful

CONS:

• Unable of generating micro dynamics and low-level details adequately
• Speakers can sound dulled if they are too close to walls or corners.
• The Inline EQ requires slightly more configuration than modern DSP-based speaker sets.

Direct or reflective?

The basic concept of the 901 has not changed since it was first introduced in 1968. Nine high-impedance full-range speakers are connected in series. Four of them emit the sound diagonally to the left and right and one straight forward directly to the listener – hence the name “Direct Reflecting.” This division determines the balance between direct and indirect sound.

Does that sound too absurd to you? Something like that can’t sound like it? If we look at the credit side, the whole thing is turning in a different direction. Technically, Bose builds an array of full-range speakers with the Bose 901 Series VI. This is how the most modern large-scale PA systems work. The membrane surfaces add up to an active surface. The membrane surfaces add up to a giant emitter, which still has the properties of a good midrange speaker in terms of impulse fidelity and precision, but now suddenly also knows how to transmit deep bass with power.

So come out of the tested 901 series VI V240 Hertz unchecked – and with a decent level. In practice, the compact little box pushes more than great volumes into the room – with the right amount of power and thrust. The individual full-range driver in the front is responsible for localization and the direct sound component, not unlike the conventional midrange driver of a three-way box. That works fine.

Equalizer

“It still can’t sound good, even if the Americans couple almost a dozen ‘midrange speakers’!” That’s right, so Bose also uses active equalization that compensates for frequency response, and that’s where Bose was way ahead of its time over four decades ago. The standard equalizer not only equalizes the frequency response across the board it also allows a very wide adjustment in the bass and the treble to adjust the tonal balance to the listening room.

In the case of stable walls, the bass can also be reduced across the board towards the deep bass. The equalizer is looped into a tape monitor between the preamp and power amp. Since the equalization sits before the amplification, this is by definition an active control. And because the power amp sits directly on the drivers, it also exerts very direct control—active speakers with room equalization that doesn’t sound absurd anymore. It comes as standard with every 901 pair, Bose’s Active Equalizer. It allows two switchable deep bass levels; the two sliders can control the tonal balance of bass and treble.

The 901- an active speaker!

Bose offers stylish feet with curved plates to match the speakers. These allow cable feedthrough if the cable is sufficiently thin. The upper plate covers the connection terminal and can be screwed to the box. Appropriate grits for pre-drilling are already applied to the bottom of the case; the only clumsy thing is the lack of a cable feed in the bottom plate of the foot. Ideally, the loudspeaker cable comes out of the floor at the right point or has a connection terminal. Otherwise, you have to give the base plate rubber feet and lay the cable through the feet.

Bose 901 Series VI- Hearing test

According to Bose 901 Series VI stands about 30 centimeters in front of the wall opposite the listening position on the comparatively low stands in the listening room. With the equalizer initially set to neutral, we play music from the server. The first impression creates a certain relief because the modern 901 also sounds significantly more modern than the historical 901, which I was previously able to experience with the German Bose boss Anton Schalkamp. Right from the start, the current box delivers significantly more detail and fine dynamics than the Series II chassis technology provided.

No wonder who knows more about small full-range speakers than Bose? And then the smile comes back to the tester’s face. Like its predecessors, the Series VI also convinces a full-bodied, almost powerful sound that you hardly believe the small box is capable of. Nevertheless, that’s a bit too much, and the second bass equalization sounds more balanced.

The 901 conveys fun

Although the Bose somehow sounds different than everything else, it still never sounds wrong. The disproportionate diffuse sound component almost sounds as if they were overwriting the recording room with the listening room. One gets the impression that the musicians are playing in their own space rather than recording. Despite the comparatively blurred stage image, this conveys an unusually high level of intimacy in the reproduction.

But what, the 18 full-range drivers can convey a good portion of dynamics, especially in musical passages with a portion of the attack. Piano attacks and drums then sound amazingly vivid, and despite certain discolorations, voices and saxophone always have charm and timbre. In short, listening to music with the Bose 901 is still a lot of fun!

Bose 901 Series VI Review