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CES 2016: Dayton Audio Constant Beam Transducer (CBT) Speakers

Vapor9

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I can't help thinking there would be a huge delay between drivers at the listening spot. Seems like this would result in a very unfocused imaging.
 
D

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It's an interesting perspective on the definition of "sideshow." I view very expensive commercial speaker designs as a "sideshow." And I wouldn't call "DIY hobbyist" even a market..per se. That said, I have seen some DIY-hobbyist speaker projects that are complete..."sideshows." :)

Luckily, these Don Keele efforts don't fall into either category.

Dave.
 

watchnerd

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It's an interesting perspective on the definition of "sideshow." I view very expensive commercial speaker designs as a "sideshow." And I wouldn't call "DIY hobbyist" even a market..per se. That said, I have seen some DIY-hobbyist speaker projects that are complete..."sideshows." :)

Luckily, these Don Keele efforts don't fall into either category.

Dave.

The easiest metric to normalize a definition for "niche" would be units sold.

As a figure of relative merit, the original JBL L100 sold 125,000 pairs in its original run. I don't know if any modern high end speaker comes even close to that.

At the other end of the spectrum, Sonos in 2018 registered 19 million speakers in 6.9 million households, worldwide. (!!!)
 

FrantzM

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HI

Based on your metrics , Revel, Toppings, etc are sideshows.. so is our hobby. Perhaps not even worth discussing...
 

watchnerd

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HI

Based on your metrics , Revel, Toppings, etc are sideshows.. so is our hobby. Perhaps not even worth discussing...

Eccentric, small-group hobbies can be fun to discuss! That's what makes them "hobbies".

Once something ceases to be useful, it can become collectible. ;)
 

jhaider

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If I had a very large room, I would pick up four of these for sides and rears.
 

beefkabob

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How about the ASR niche of people concerned with sound and value? I'd like speakers that fill a room reasonably well with clarity more than give perfect sound in one small area. There are also pro speakers with this cbt design for much less money, made for churches, gyms, and the like. Just gotta get a used crown amp for the 100v system. Or am I best off with a dj style pa for that?
 
D

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The easiest metric to normalize a definition for "niche" would be units sold.

As a figure of relative merit, the original JBL L100 sold 125,000 pairs in its original run. I don't know if any modern high end speaker comes even close to that.

At the other end of the spectrum, Sonos in 2018 registered 19 million speakers in 6.9 million households, worldwide. (!!!)
Who gives a shit about vintage JBL or current Sono sales....or even whether the CBT speaker is a "niche" product or not.
The CBT project is an interesting approach and design, regardless.

Dave.
 

Blumlein 88

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https://www.amazon.com/JBL-Line-Array-Column-Loudspeaker/dp/B0045WSF1K

http://www.jblpro.com/www/products/installed-sound/cbt-series

These appear to be similar technology. Are those from Dayton developed further?

I also wonder does the sound level staying the same over such a wide level or nearly so effect stereo imaging?

And how do these score on a spin-o-rama test?

And Meyer and others have been making large line arrays for use in big concert venues for a few years.
https://www.soundonsound.com/techniques/line-arrays-explained

1565751008633.png


This is a good graphic.
1565751132630.png
 

Ilkless

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https://www.amazon.com/JBL-Line-Array-Column-Loudspeaker/dp/B0045WSF1K

http://www.jblpro.com/www/products/installed-sound/cbt-series

These appear to be similar technology. Are those from Dayton developed further?

I also wonder does the sound level staying the same over such a wide level or nearly so effect stereo imaging?

And how do these score on a spin-o-rama test?

And Meyer and others have been making large line arrays for use in big concert venues for a few years.
https://www.soundonsound.com/techniques/line-arrays-explained

This is a good graphic.

As I understand it, the main innovation that makes the Parts Express CBTs different from most of the live sound ones is that they are ground-plane CBTs. This is a variation intended for floor placement and eliminating floor bounce. The authoritative overview is probably Don's own website here.
 

Midwest Blade

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Saw and heard these at the PE booth at Axpona a few years ago, sound and imaging was very good. Would love to hear these set up in a room with and without a sub. I read up on Don Keele and find him to be quite genuine.
 

Rick Sykora

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I bought CBT24s at the end of last year. As evidence-based designs go, Keele puts these over the top by far. Yes, they could be considered aesthetically challenged, but my wife likes them.:) The engineering behind them convinced me to try and am thrilled I did. Here are the major attributes:
  • Broad listening sweet spot due to more uniform sound distribution
  • Less room interaction (no major floor bounce response dip, much lower wall and ceiling reflections)
  • No crossover avoids nasty phase, power loss and distortion issues
  • Linear phase and time-aligned for the frequencies where human hearing is most sensitive
  • Much less sensitive to placement in room
  • Reasonably priced (readily outperform speakers that are 10 times the price)
I got one of the last finished pairs during PE’s closeout (same price as the DIY kit). To get beyond a niche product, they need a smaller, turnkey model, but not sure how well they scale. Along with the larger listening spot, they do image well too. They do need a subwoofer for best effect, but apartment owners could get by without one.

It would be a shame if we lose what Keele has accomplished here. Would really hope JBL repackages a CBT for the consumer market as PE has reduced its offerings.
 

Ilkless

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I bought CBT24s at the end of last year. As evidence-based designs go, Keele puts these over the top by far. Yes, they could be considered aesthetically challenged, but my wife likes them.:) The engineering behind them convinced me to try and am thrilled I did. Here are the major attributes:
  • Broad listening sweet spot due to more uniform sound distribution
  • Less room interaction (no major floor bounce response dip, much lower wall and ceiling reflections)
  • No crossover avoids nasty phase, power loss and distortion issues
  • Linear phase and time-aligned for the frequencies where human hearing is most sensitive
  • Much less sensitive to placement in room
  • Reasonably priced (readily outperform speakers that are 10 times the price)
I got one of the last finished pairs during PE’s closeout (same price as the DIY kit). To get beyond a niche product, they need a smaller, turnkey model, but not sure how well they scale. Along with the larger listening spot, they do image well too. They do need a subwoofer for best effect, but apartment owners could get by without one.

It would be a shame if we lose what Keele has accomplished here. Would really hope JBL repackages a CBT for the consumer market as PE has reduced its offerings.

I think a planar-style transducer like a ribbon is best suited for a CBT, if more R&D could be put into the concept. Think a single ribbon transducer bent to form the CBT arc and have the shading as a continuous function decreasing smoothly towards the top, rather than having discrete -3dB or -6dB shading networks.
 

Rick Sykora

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I think a planar-style transducer like a ribbon is best suited for a CBT, if more R&D could be put into the concept. Think a single ribbon transducer bent to form the CBT arc and have the shading as a continuous function decreasing smoothly towards the top, rather than having discrete -3dB or -6dB shading networks.

Have wondered about this too, but am not sure about feasibility. Certainly would require some significant investment. One potential benefit would be a smoother shading function. The CBT 24 driver array is more of a step function of the Legendre shading. That said, it is surprisingly effective despite being an approximated curve fit.

Given how cheap amplification is getting, might be easier to implement with individual drivers with dedicated small amplifiers. ;)
 
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Rick Sykora

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Rick Sykora

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