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B&W spaciousness from Bose-like reflection?

skyfly

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Let us consider the Bowers & Wilkins loudspeakers with tweeter without baffle.

Is the spaciousness of these loudspeakers partly from the reflection of upper mid and lower high from the wall behind the loudspeaker?

The tweeter without baffle will radiate quite an amount of sound (though not much in the top octave) to the back of the the tweeter by the phenomenon called in physics "diffraction" (like low frequency sound propagates also to the rear of the speaker having a front-mounted woofer). That sound will be reflected from the wall with some time delay. This is something we have with some Bose loudspeakers.

I see from Steropohile 702 S2 specificatgion page ( 4kHz (second-order LP, first-order HP)" ) that the tweeter of such a model has 1st order high-pass filter. So measured from the front, the frequency response curves do not look nice for speaker of that price. However, there will be the rear firing (by diffraction, I do not mean the sound escaping the hole at the back of the tweeter enclosure) upper mid and lower high frequency that many other loudspeakers lack.

For those who are allergic to the name "Bose," let me mention a different name those people admire.

Some Burmester (a German high end brand) speaker models have a tweeter mounted at the back-side of the enclosure. Bowers & Wilkins speakers without tweeter baffle might have similar effect by diffraction.
 
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Which B&W speakers are you talking about? What is spaciousness?
 
Which B&W speakers are you talking about? What is spaciousness?
"Bowers & Wilkins loudspeakers with tweeter without baffle."

702 S2, 702 S3, 703 S3, all 800 seires

A feeling as if I am in the hall where the music is being played (sound stage?) (coming from the reflected sound recorded by the microphones strategically placed by the recording engineer, or from electronic reverb treatment by the music producer)
 
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"Bowers & Wilkins loudspeakers with tweeter without baffle."

702 S2, 702 S3, 703 S3, all 800 seires
So the cute little bullet shaped things on top? :)

I'm not much of a fan of the sound, what particularly is spacious in terms of what can be measured rather than just your perception?

I almost put B&W in the Bose category in some respects....not a speaker I'd buy.
 
Not from that specific reflection, but from relatively wide treble dispersion, yes. However, there are better ways to do this, including dipolar radiation, rear mounted tweeters and so on. B&W is a compromised brand that is too invested in a distinctive speaker appearance that is fundamentally flawed - no state of the art speakers use the 'minimum baffle' approach, it is as anachronistic as Vandersteen, they just make it look good.

The best way to create spaciousness is probably to create a reflective room that doesn't eat high frequencies, and to implement a speaker which uses narrow directivity to avoid early reflections. Such speakers tend to be large, expensive and often ugly, so B&W thrives.

The bose approach is honestly underrated, and it cannot be denied that the better bose designs achieve things that contemporary competitors could not achieve. The 80s were a period of incredible experimentation in terms of loudspeaker radiation, just look at DCM, Bose, Gradient and Ohm. Far more progressive than the focus group Harman hegemony we see now.
 
Assuming that we all know that we must not judge a speaker’s sound by youtube, I post these for fun. I am not related to the two loudspeaker brands or the (seemingly - I don’t know that language - ) hi-fi retailer who made the video.

Bowers & Wilkins 702 S3

JBL S3900
 
Interestingly a lot of classical recording studios use B&W speakers! So if they were that bad would they still use them?

Used to own 800Diamond 2, sold them old and bought KEF Reference Meta ;)
 
Assuming that we all know that we must not judge a speaker’s sound by youtube, I post these for fun. I am not related to the two loudspeaker brands or the (seemingly - I don’t know that language - ) hi-fi retailer who made the video.

Bowers & Wilkins 702 S3

JBL S3900
So how would one listen to those particularly as a way to judge?
 
Assuming that we all know that we must not judge a speaker’s sound by youtube, I post these for fun. I am not related to the two loudspeaker brands or the (seemingly - I don’t know that language - ) hi-fi retailer who made the video.

Bowers & Wilkins 702 S3

JBL S3900
Trying to hear the difference on YouTube is hilarious
 
I wish somebody measures Bowers & Wilkins 702 S3 or 804 D4 with Klippel so that we can get some idea about the 3D radiation pattern from the tweeter without baffle.

If it is a flawed design, a competitor of Bowers & Wilkins can buy and send a 702 S3 or 804 D4 to ASR or Erin to reveal the flaw so that customers can make a more informed decision.

Any speaker design has some flaws. I am not trying to bash Bowers & Wilkins.

The possible sound to the rear due to the absence of baffle may not be something everyone has to reject. In some environment such as a control room with a large glass panel, it could be a deal breaker. I wish customers have more information on the unique Bowers & Wilkins design.
 
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The information you are looking for can be found in a spinorama. The Bose 901 was measured by Erin on his Klippel.

Bose%20901%20Series%20V%20(Bass%202%20-%20EQs%20Neutral)_Horizontal_Spectrogram_Full.png

It was designed to radiate most of the sound to the back of the speaker. The spinorama confirms that it does that.

Bose%20901%20Series%20V%20(No%20EQ)_SPIN.png


I look at this and think to myself "hmmm, this must be a pretty fun sounding speaker". I confess I get a bit bored listening to one perfect speaker after another and I would LOOOVE to listen to something that measures as poorly as this because I am curious what it would sound like. Sadly I have never had the opportunity to listen to a pair of Bose 901's.

The best measurements I could find of a B&W product is the B&W 802 D2. These speakers have that little bullet shaped tweeter on the top.

802D2%20DI%20and%20Power.png


The measurements show a U-shaped frequency response. In other words, this is another "fun" loudspeaker. I am sure the B&W engineers know what they are doing - they are after all a pretty large company. So I can only assume that they made this decision deliberately. Why they did this is anybody's guess. Yet the speakers still sell and get recommendations from reviewers!

The lower measurement consists of 10 curves starting from 0 degrees to 90 degrees in 10 degree steps showing horizontal directivity. It takes a bit of imagination to convert this into a polar plot but you can see that it is anything but smooth. It already starts off with a 5dB dip between 2-3kHz and by 90 degrees the dip is pretty massive - almost 20dB!! Toole says that an ideal loudspeaker has a flat anechoic on-axis FR with smooth directivity. This particular speaker doesn't come close.

I have heard this loudspeaker, and I am not a fan. I was so preoccupied with that easily audible gaping hole that I forgot to listen for spatial qualities.

Your question was about spatial qualities. I can't find ANY spinoramas of any B&W speaker, but what we can see so far: the Bose 901 gets louder to the rear of the loudspeaker. It's like taking a normal speaker and spinning it around so that it fires towards the wall. The B&W 802 D2 does not do that. Maybe it might if you were to turn it around so that it back is facing you. This would cause the reflections will be as loud or louder than the on-axis sound.

I doubt if the overall effect would be pleasing.
 
Baffle effect resulting in tweeter firing backwards? I think you'd need to find tweeters that can radiate past 90 degrees first...
 
Baffle effect resulting in tweeter firing backwards? I think you'd need to find tweeters that can radiate past 90 degrees first...
You might have misread my post. Tweeter without baffle may result in more sound propagating rearward than tweeter with baffle (or wave guide).

You understand a speaker, with enclosure, with front mounted woofer radiates bass (or even low mid) sound rearward. Consider the wavelength of 4kHz and the diameter of the Bowers&Wilkins tweeter (about an inch). You can understand that quite a lot of sound from the tweeter (if wave guide or baffle is absent) will propagate rearward.

Note the choice of 1st order high pass filer in Bowers & Wilkins 702 S2 stated on Stereophile. Non negligible sound from tweeter at 2 kHz and 1 kHz. At those frequencies, the tweeter without baffle is more like the bass from conventional box speaker: closer to 360 degrees equal radiation.
 
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The information you are looking for can be found in a spinorama. The Bose 901 was measured by Erin on his Klippel.

Bose%20901%20Series%20V%20(Bass%202%20-%20EQs%20Neutral)_Horizontal_Spectrogram_Full.png

It was designed to radiate most of the sound to the back of the speaker. The spinorama confirms that it does that.

Bose%20901%20Series%20V%20(No%20EQ)_SPIN.png


I look at this and think to myself "hmmm, this must be a pretty fun sounding speaker". I confess I get a bit bored listening to one perfect speaker after another and I would LOOOVE to listen to something that measures as poorly as this because I am curious what it would sound like. Sadly I have never had the opportunity to listen to a pair of Bose 901's.

The best measurements I could find of a B&W product is the B&W 802 D2. These speakers have that little bullet shaped tweeter on the top.

802D2%20DI%20and%20Power.png


The measurements show a U-shaped frequency response. In other words, this is another "fun" loudspeaker. I am sure the B&W engineers know what they are doing - they are after all a pretty large company. So I can only assume that they made this decision deliberately. Why they did this is anybody's guess. Yet the speakers still sell and get recommendations from reviewers!

The lower measurement consists of 10 curves starting from 0 degrees to 90 degrees in 10 degree steps showing horizontal directivity. It takes a bit of imagination to convert this into a polar plot but you can see that it is anything but smooth. It already starts off with a 5dB dip between 2-3kHz and by 90 degrees the dip is pretty massive - almost 20dB!! Toole says that an ideal loudspeaker has a flat anechoic on-axis FR with smooth directivity. This particular speaker doesn't come close.

I have heard this loudspeaker, and I am not a fan. I was so preoccupied with that easily audible gaping hole that I forgot to listen for spatial qualities.

Your question was about spatial qualities. I can't find ANY spinoramas of any B&W speaker, but what we can see so far: the Bose 901 gets louder to the rear of the loudspeaker. It's like taking a normal speaker and spinning it around so that it fires towards the wall. The B&W 802 D2 does not do that. Maybe it might if you were to turn it around so that it back is facing you. This would cause the reflections will be as loud or louder than the on-axis sound.

I doubt if the overall effect would be pleasing.

The information I am looking for about Bowers & Wilkins cannot be found on the web (including Erin's site).

Yes, I want +/- 180 degrees plot of the type you posted (for Bose 901 IV) or of another type, the polar plot (Erin calls it globe plot).
JBL%204367_360_Horizontal_Polar.png
 
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I wish somebody measures Bowers & Wilkins 702 S3 or 804 D4 with Klippel so that we can get some idea about the 3D radiation pattern from the tweeter without baffle.

If it is a flawed design, a competitor of Bowers & Wilkins can buy and send a 702 S3 or 804 D4 to ASR or Erin to reveal the flaw so that customers can make a more informed decision.

Any speaker design has some flaws. I am not trying to bash Bowers & Wilkins.

The possible sound to the rear due to the absence of baffle may not be something everyone has to reject. In some environment such as a control room with a large glass panel, it could be a deal breaker. I wish customers have more information on the unique Bowers & Wilkins design.
The 805s with the eye-of-beholder tweeter was measured here at ASR:
It has a host of issues, the directivity mismatch between the woofer and tweeter being one of them.

Sinorama.org has measurements from B&W on several models. Their own measurements on the 802n (for instance) show the effect of the interaction between the tweeter and midrange:
CEA2034.jpg
 
The 805s with the eye-of-beholder tweeter was measured here at ASR:
It has a host of issues, the directivity mismatch between the woofer and tweeter being one of them.

Thanks for the link.

So it is already known that Bowers & Wilkins speakers without tweeter baffle radiate more amount of high frequency energy rearward than speakers with tweeters with baffle. So there have been Bose-like rear-reflected-sound effect on Bowers & Wilkins speakers.
Doc1 copy.png
 
Frontal response curves of Bowers & Wilkins are known to be mediocre. See the graphs of 804 D4 measured by a German magazine Audio: axial, 10 degrees above, 30 degrees side.

P.S.: I am surprised by the bass extension of 804 D4 with the slim not-big tallboy style enclosure with merely two 165 mm diameter woofers.
 

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Thanks for the link.

So it is already known that Bowers & Wilkins speakers without tweeter baffle radiate more amount of high frequency energy rearward than speakers with tweeters with baffle. So there have been Bose-like rear-reflected-sound effect on Bowers & Wilkins speakers.
View attachment 372419
I tend to not listen while behind the speaker.;)
You should read up on interpreting spinorama, I think you have jumped to several conclusions regarding so-called 'spaciousness'.
Have you ever heard a Bose 901? They really have nothing in common with the sound of one of these beaming B&Ws.
 
Interestingly a lot of classical recording studios use B&W speakers! So if they were that bad would they still use them?

Used to own 800Diamond 2, sold them old and bought KEF Reference Meta ;)
They're given free for promotional reasons, or at least were... Even Abbey Road have other monitors now, not simply blanket B&W 800s now. One important mastering suite has double boxed large PMC's and one of the recording studios a return to ATC I from pics.
 
I have measured the B&W 804S:

The on-axis response and directivity looks weird, but the dip is almost gone at listening position in my room, and comes back when the measurement is gated, so it must be filled in by room reflections.

I measured at 0-170 degrees, but didn't include >90 deg since I don't know how reliable those results are. Anyway, here they are:

804s hor 0-170 tweeter axis.png



edit: 702 S2 has a similar on-axis dip, and off-axis peak:
 
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