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

[beefkabob]

I looked at the CBT, but then I couldn't hear them and they seemed risky. Plus I didn't want to assemble. Better off with a studio monitor, methinks.

 

[q3cpma]

Looks very cool. The need for homemade crossover and EQ definitely puts it in the hobbyist section, though.

 

[Ron Texas]

Bass rolls off starting @ 200 Hz. That indicates a high crossover for the sub. Most subs don't like to go all that high. Another hobbyist feature I guess as no sub is supplied and one is needed.

 

[Rick Sykora]

Yes, no doubt on the hobbyist front. All that is currently left on the market is the CBT24 kit.

No problem on blending with subwoofer though. Real in-room response is usually much better than a lab measurement. Audyssey set mine to 80 Hz and REW measures flatter through the transition than some of the upper bass. Also, only crossover and eq I am using are built into my AVR. Am down a subwoofer right now, so could be even better as I normally run dual subwoofers.

 

[Ilkless]

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.

Seeing how we have curved electrostats out on the market already (Muraudio), and RAAL did an omni array of ribbons a decade back, it might not be too far off.

 

[jhaider]

Would really hope JBL repackages a CBT for the consumer market as PE has reduced its offerings.

JBL Synthesis had a CEDIA demo system 5 years ago with M2 in front and CBT50 pro speakers as surrounds.

https://www.audioholics.com/editorials/speaker-demos-cedia-2015

Dr. Toole also has language in both old and new Sound Reproduction about CBT making a very good surround speaker.

 

[amirm]

JBL Synthesis had a CEDIA demo system 5 years ago with M2 in front and CBT50 pro speakers as surrounds.

https://www.audioholics.com/editorials/speaker-demos-cedia-2015

I was there and it sounded good. CBTs solve a big problem for rear channels as the difference between near and far is not as much as traditional speakers.

 

[Bjorn]

Here's a first prototype we did. The new one will have a lot of changes.

 

[Rick Sykora]

I was there and it sounded good. CBTs solve a big problem for rear channels as the difference between near and far is not as much as traditional speakers.

Do not doubt this sounded good. A bit overkill for my family room though ...

Rather than CBT50s, Don Keele advised that I use another pair of CBT24s as surrounds, so I tried with my existing pair and ran traditional monopoles as front speakers. This was not nearly as dramatic an impact as having the CBT24s as front speakers in my 12 x 25 home theater. This was particularly true when listening to music in stereo and that is my primary use anyway.

 

[Biblob]

Here's a first prototype we did. The new one will have a lot of changes.

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Awesome to hear this still keeps being researched. Do you have measurements you could share with us?

 

[Bjorn]

Awesome to hear this still keeps being researched. Do you have measurements you could share with us?

Since this is a prototype that will not be released, there isn't much point in sharing measurements of it Besides, it never was measured anechoic or without room contribution low in frequency. Measurements will be shown of the actual model that will be sold of course.

What can be said is that with a speaker that is textbook vertically, avoids floor reflections, minimizes ceiling reflections, and has few side lobes it generally gives a frequency response in most rooms that is very even and that few speakers achieve. A 2-way version with good drivers also has much lower distortion than what's common in speakers.

 

[rajapruk]

I was there and it sounded good. CBTs solve a big problem for rear channels as the difference between near and far is not as much as traditional speakers.

A test of a JBL CBT-series speaker would be very welcome. E.g JBL CBT50. I am considering to use this as surround speaker.

 

[Biblob]

Since this is a prototype that will not be released, there isn't much point in sharing measurements of it Besides, it never was measured anechoic or without room contribution low in frequency. Measurements will be shown of the actual model that will be sold of course.

What can be said is that with a speaker that is textbook vertically, avoids floor reflections, minimizes ceiling reflections, and has few side lobes it generally gives a frequency response in most rooms that is very even and that few speakers achieve. A 2-way version with good drivers also has much lower distortion than what's common in speakers.

I'm very curious for when it will be it will be ready. Is there a release date or goal?

 

[Bjorn]

I'm very curious for when it will be it will be ready. Is there a release date or goal?

Only a goal. Before late summer. Also waiting for the right DSP to sell with it. There are no DSP units today that meet the criterias.

 

[Ilkless]

Only a goal. Before late summer. Also waiting for the right DSP to sell with it. There are no DSP units today that meet the criterias.

Hypex, DEQX?

 

[Bjorn]

Hypex, DEQX?

None of those. There a few options on the way or developing something under Vera Audio is also possible. We'll see.

 

[Biblob]

None of those. There a few options on the way or developing something under Vera Audio is also possible. We'll see.

Take a look at this: Auverdion Aurora DSP

 

[Ilkless]

What can be said is that with a speaker that is textbook vertically, avoids floor reflections, minimizes ceiling reflections, and has few side lobes it generally gives a frequency response in most rooms that is very even and that few speakers achieve. A 2-way version with good drivers also has much lower distortion than what's common in speakers.

This is a very interesting point, because the native, anechoic response of CBT speakers (eg. the CBT24) is limited by the configuration (wideband drivers, and their intrinsic rougher directivity in HF, side lobes), but the way the overall array disperses vastly reduces the worst room-related contribution (as you said, floor and ceiling reflections) in any room. I wish there were a way to quantify/parameterise this room-independence/consistency because I don't think even the power response or Spinorama would.

 

[Bjorn]

If even frequency response is the primarily goal (which I don't think it should only be), a speaker with both a limited and uniform dispersion vertically and horiozontally is the best way to achieve that for most rooms. This CBT does that vertically and also minimizes the low freq. floor bounce greatly but horizontally it's wide.

I'm working on both horns and CBTs. A CBT with wide dispersion is really a much better backround speaker in a decent size room. The horn has other strengths. By the way, a CBT speaker can also be designed with a narrow horizontal directivity.

 

[Ilkless]

My concern lies more with ragged HF directivity (at least for those using widebanders) and complex lobing patterns (eg. side lobes as you said) vs the typical multi-way format (relatively sparse, narrowband lobes), despite the clear ability to minimise floor and ceiling bounce. You gain a massive advantage in minimising the bounce, but I'm not sure whether it outweighs the cost. Not saying it doesn't, but I really don't know which way it goes. Really excited to see your product though. Do you know how the JBL Professional CBTs perform vs the designs Keele has released independently (from Parts Express, Selah Audio and you iirc).