I'm wondering if any do-it-yourselfers has ever tried a design like this.
http://assets.bowers-wilkins.com/med/Libraries/3/SignatureDiamond_03_l2_w817_h328.jpg
http://assets.bowers-wilkins.com/med/Libraries/3/SignatureDiamond_11_l2_w817_h328.jpg
These are from the Bower & Wilkins Signature series.
As I was reading several discussion about how critical baffle width is to a speaker design, and how problematic baffle edges are, the concept of the B&W Signature series came into my mind, though at the time I thought I had come up with something original.
Essentially, you have a curved front cabinet that has no width or edges; more or less. Into that you make small round vertical tunnels just wide enough to mount the speakers. In my mind I had envisioned a multi-woofer design in an WWMT configuration.
Conceptually it seems like a good idea, but there must be some drawbacks besides the complexity of construction. Which seem fiddly but not all that complicated.
So, to your knowledge, has anyone tried this, and can anyone tell me what the advantages and disadvantages of this design would be?
Just curious. It seemed like a good idea, and I'm surprised lots of people haven't thought of it and tried it.
Steve/bluewizard
http://assets.bowers-wilkins.com/med/Libraries/3/SignatureDiamond_03_l2_w817_h328.jpg
http://assets.bowers-wilkins.com/med/Libraries/3/SignatureDiamond_11_l2_w817_h328.jpg
These are from the Bower & Wilkins Signature series.
As I was reading several discussion about how critical baffle width is to a speaker design, and how problematic baffle edges are, the concept of the B&W Signature series came into my mind, though at the time I thought I had come up with something original.
Essentially, you have a curved front cabinet that has no width or edges; more or less. Into that you make small round vertical tunnels just wide enough to mount the speakers. In my mind I had envisioned a multi-woofer design in an WWMT configuration.
Conceptually it seems like a good idea, but there must be some drawbacks besides the complexity of construction. Which seem fiddly but not all that complicated.
So, to your knowledge, has anyone tried this, and can anyone tell me what the advantages and disadvantages of this design would be?
Just curious. It seemed like a good idea, and I'm surprised lots of people haven't thought of it and tried it.
Steve/bluewizard
Yes, but the edge you refer to is unavoidable as it is the edge of the woofer. Essentially, the baffle width and the woofer width are one and the same.
Now, I suppose one could make the speaker mount slightly wider and roll the edges. That takes care of edges.
Though if you look closely at the photos, you will see that the edge beyond the edge of the speaker is beveled back. So it not that sharp an edge.
But in terms of baffle width, it would seem physically impossible for the baffle width to be narrower.
Again, I'm only curious. It seems that baffle width either needs to be infinitely large or infinitely small, or heavily compensated for.
With a few tweaks, it would seem that this design could come as close to infinitely small baffle width as is humanly possible.
Again, just for fun.
Steve/bluewizard
Now, I suppose one could make the speaker mount slightly wider and roll the edges. That takes care of edges.
Though if you look closely at the photos, you will see that the edge beyond the edge of the speaker is beveled back. So it not that sharp an edge.
But in terms of baffle width, it would seem physically impossible for the baffle width to be narrower.
Again, I'm only curious. It seems that baffle width either needs to be infinitely large or infinitely small, or heavily compensated for.
With a few tweaks, it would seem that this design could come as close to infinitely small baffle width as is humanly possible.
Again, just for fun.
Steve/bluewizard
I find Pluto visually a marvel. Auditively maybe. At one condition : just like same author's Orions, far away from any wall. And I think it is exactly the same for any speaker with small front baffle.
Such positioning is not possible for many people who have space constraints with their room. For this case, I have been investigating the radically opposite way, the two pi emission, just like the Sonus Faber Stradivari Homage
http://www.sonusfaber.com/eng/home.html
My current speakers are 2 ft wide with 1/2 ft rounded corners, slightly angled and about 2 1/2 away from the rear wall.
I think I won't soon come back to smaller baffles in my current room.
Such positioning is not possible for many people who have space constraints with their room. For this case, I have been investigating the radically opposite way, the two pi emission, just like the Sonus Faber Stradivari Homage
http://www.sonusfaber.com/eng/home.html
My current speakers are 2 ft wide with 1/2 ft rounded corners, slightly angled and about 2 1/2 away from the rear wall.
I think I won't soon come back to smaller baffles in my current room.
BlueWizard said:
Hi,
a) Is true but it is the worst shape for baffle step ripple and has an abrupt edge.
b) Is not possible, the smallest baffle size is the size of the driver.
The design has excellent inherent rigidity but not the smoothest
diffraction response, that is a truncated ovoid or sphere.
sreten.sreten said:
Hi,
a) Is true but it is the worst shape for baffle step ripple and has an abrupt edge.
b) Is not possible, the smallest baffle size is the size of the driver.
The design has excellent inherent rigidity but not the smoothest
diffraction response, that is a truncated ovoid or sphere.
The shape and size alone aren't the sole determinants of diffraction artifacts. The B&W driver midwoofer unit shown is fairly large and will become more directional at lower frequencies due to both depth and diameter. It's a waveguide of sorts designed to have an increasingly narrow radiating area as frequency rises.
Measurements of lesser quality drivers of this size that I've made show diffraction even on modest boxes to be minimal for drivers that size other than baffle step. I would expect no diffraction artifacts other than step for that B&W unit mounted as it is.
The tweeter will also show little impact. It's 4-pi very early due to the configuration. The diffracted signal that is quickly in the 4-pi range will be very highly dispersed, so the impact on any single specific axis will be minimal as well.
B&W takes just about everything into consideration in their designs. Significant diffraction would be dealt with in their better systems. I'd say that they've handled diffraction quite well in this case, aesthetics notwithstanding.
Dave
Hello guys,
I know well the issues of baffle step in the frequency domain. But what about this matter in the time domain?
For instance, assume a very narrow baffle with full BSC and a very large baffle with no BSC giving the same fr response. Will the narrow baffle be more time coherent/accurate than the large baffle?
Thanks.
I know well the issues of baffle step in the frequency domain. But what about this matter in the time domain?
For instance, assume a very narrow baffle with full BSC and a very large baffle with no BSC giving the same fr response. Will the narrow baffle be more time coherent/accurate than the large baffle?
Thanks.
That's difficult to answer because first you need to define what is 'narrow' and 'large'. To do without BSC to a low enough F3 (say 40Hz) requires baffles several metres wide.
The actual BSC compensation network will not subjectively change the coherence of the speaker as it will only change the phase maybe 20 or 30degrees at the BSC corner frequency. This is not subjectively audible.
What is subjectively audible are late reflections (several hundreds of degrees phase delays), created by the room. So ultimately it comes down to if either baffle configuration allows you to place the speaker in your listening space as to reduce room effects more than the other one.
Thanks guys for your replies.
I guess I have to specify my question.
Assume a perfect similar frequency response from a large baffle and from a narrow one in a definite bandpass. The narrow baffle uses BSC, the large one uses no BSC.
Instead of looking at the 4pi radian as a loss, look at the 2pi radian as a gain. This gain comes from the waves rebouncing on the baffle.
Is it correct to say that these waves bounces are delayed in time and that the ones with BSC aren't delayed?
Thanks.
I guess I have to specify my question.
Assume a perfect similar frequency response from a large baffle and from a narrow one in a definite bandpass. The narrow baffle uses BSC, the large one uses no BSC.
Instead of looking at the 4pi radian as a loss, look at the 2pi radian as a gain. This gain comes from the waves rebouncing on the baffle.
Is it correct to say that these waves bounces are delayed in time and that the ones with BSC aren't delayed?
Thanks.
Time domain issues no longer make me wake up at night...
What i find a real nightmare is that there is no real cure for baffle step since BSC or not, you will never get both constant power and flat spl response: whatever you do you get a 3db mismatch.
This is imho the real issue with narrow baffles...
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