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B&W's extraordinary support

booja30

pfm Member
I own a pair of B&W 683 S2s that I bought from @manicatel of PFM. I came across a brochure recently and spotted something odd about one of the specs. It seemed that while the 683 and 683 S2 are very similar with respect to driver configurations, the frequency response changed quite a bit between models. I sent a brief email to B&W asking about the frequency response of the speakers, hoping they could confirm a value. The same day I received a very thorough response from someone at B&W:

Thanks for your email enquiry regarding the bass response of our speakers.

We specify two parameters – ‘frequency response’ and ‘frequency range’.

  • Frequency response is a measure of the response’s flatness with varying frequency and gives the frequency extremes between which the response keeps within +/-3dB limits.
  • Frequency range gives the frequency extremes where the output level has fallen by 6dB relative to the average level in the flat region defined by the limits of frequency response.
When used in real rooms, floor-standing speakers get more perceived bass reinforcement than do stand-mount speakers, simply because they reach down to the floor.

Unfortunately, if you try to measure any speaker in a real room, you get all sorts of measurement deviations due to reflections and room modes. Not only that, but you get a different result if you change rooms or if you merely change the position in the same room.

For that reason, all measurements are normally made in anechoic conditions, which enable more repeatable results because the speaker’s performance is isolated from its surroundings. It is the job of the speaker designer, then, to choose an anechoic alignment that sounds right when the speaker is listened to in a real room and this tends to be different for each model.

This graph shows the bass responses of the two bookshelf (686 S2 & 685 S2) and the two floor-standing (684 S2 & 683 S2) models in the 600 Series, taken under anechoic conditions. They have been adjusted for level so that 0dB represents the mean level in the midrange and high frequency regions.
(For the benefit of anyone used to seeing measurements made in an anechoic chamber, to whom these measurements may seem a little too smooth; they were actually computed from Thiele-Small parameters derived from a fit to the impedance. This avoids the bass inaccuracies found in all anechoic chambers.)

50512738697_75a33f1372_z.jpg


You can see that the bookshelf responses are more or less classic maximally flat alignments, but the responses of the two floor-standing models begin to slope downwards from a fairly high frequency in order to offset the reinforcement from the floor, which gradually increases as the frequency decreases.

Looking in more detail at the responses of the 685 S2 and 684 S2, we see that they have more or less the same -6dB frequency, but the larger 684 has a higher -3dB frequency, which on simply reading the figures from a specification sheet seems odd. There is no doubt, however, that the 684 actually sounds to have more bass in a real listening room situation. This is because the level is reinforced by floor coupling and, once you go below 45Hz, the 684 has more output. It sounds correctly balanced and with more extension.

In summary, the specifications are correct, taking into account the bass alignment for the design employed and the room reinforcement.

I trust this is of use to you, however, if there is anything else, please feel free to come back to me, I'll be happy to assist.

Kind regards,
Stephen
Bowers & Wilkins

None of this seemed like a cut and paste kind of response like I've received in the past from various companies/vendors. It gives specific information pertaining to the models I had asked about.

Note that the 683 S2 isn't a current product, and I already own them, so there isn't a big incentive to offer this kind of support. I am thoroughly impressed with this level of service! Rega is the only other audio related company I have dealt with that has stood out like this.
 
Bryston (via PMC) is by far the best I have experienced, along with Rega. I had my first B60R amp, that was still in its 20-year warranty and despite being through many owners, no issues arranging a return and repair under warranty. They also found one of the phono sockets was a little loose and replaced that part before it was actually broken, and cause problems further down the line.
 
That is pretty impressive, not had a massive amount of experience with B&W in my home (I tried some N805Ds for a while, liked a lot of what they did and can fully understand why people love them), and what I will say, is that they’re extremely nicely built and finished for their respective price points, they do seem like a company that care about quality... that’s usually a very good start.
 


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