I don't need to. I have Stereophile to do that for me. They have measured the D1, D2, and D3.
What difference does it make if I have measured the D3 when Stereophile has done that?
Anyone can see these measurements.
Based on these Stereophile measurements, anyone can see that the cheap Infinity P362 have much better on-axis and off-axis FR than any B&W D series.
Are you claiming that your measurement is more accurate than Stereophile ?
Are you saying that the Stereophile FR measurements are inaccurate and we should view your measurement as the correct one?
First of all Stereophile have not measured the B & W 800 D3, they measured the 802 D3.
This is the FR Stereophile got from the 802 D3.
I would grant that the probability that the mid tweeter crossover being the same is high, but that the woofer mid would have to be different.
I made my measurements carefully after a prolonged listening session. However mine and their measurements were made under different conditions.
Having built and voice speakers since a young child, heard lots of live music and have made several hundred live recordings I consider myself an experienced listener.
All I can say is that the Stereophile measurements would indicate that the speaker would have a degree of sibilance, and yet I detected not a trace of it. In addition the speaker would be expected to sound somewhat forward. The speaker infact sounds slightly recessed which is much more in line with the slight dip in response I measured at 5 KHz.
So I can only say this, that what I heard of the speakers, and I have now listened to them on many occasions, is much more concordant with my measurements than Stereophile's.
But you are correct that measurements are not everything, especially the FR as it says nothing about time. It is perfectly possible to build a speaker with a perfect FR that would be totally useless, with speech totally unintelligible.
So measurements are useful. If the FR is awful it will not be a good speaker, but a good FR alone does not make it a good speaker.
So fine tuning a design is a combination of measurement but also prolonged listening should also be a guide to properly voicing a speaker.
I was taught years ago, by John Wright of TDL than once you had the speaker in your opinion good, to listen to it for prolonged periods, and not make changes more often than every 3 to 4 months. If you are an experienced listener and critical you won't get used to sound of a speaker, as many do, but minor blemishes will bug you more and more over time, and force you to get it right.
Lastly we have to come to the source of the music for evaluation. That means only natural instruments and the natural human voice unamplified or in anyway modified are acceptable point of reference.
By far the best is music recorded in a venue you know well. So you need to have experience of live orchestras, chamber groups, choirs, a wide variety of solo instruments, including a wide variety of pipe organs, and solo voices.
Those are the dues you have to pay to became a critical listener.
This is why I think that the market for better but not uniformly high end speakers are picked by individuals who listen often to the type of program I have outlined.