We've looked at a straight version. It would require eiher DSP or multiple amps. The DSP capability isn't available today. Multiple amps with low distortion will bring the cost up. Thus, not something that we plan in near future for the home market.
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Constant Beamwidth Transducer (CBT) Speakers
- Thread starter Rick Sykora
- Start date
We completely redesigned the shading network which improved the polar. This has taken a lot of time. Still some work to do for the practical implementation of the network.
Yes, the horn design is basically ready. It's now a matter of working out the finish and implementing the DSP. It's 2-way horn with exceptional uniform directivity combined with a separate subwoofer with dual 18" woofers.
Pictures of the midbass horn below.
Beautiful work!
Height, width relate directly to lowest frequency of pattern control. Physics is annoying.Wow! I think I’m gonna need a bigger boat (aka, listening room). I certainly didn’t expect those monsters. Beautiful work indeed, but my wife would divorce me if I brought those into the house. I expect for the lucky folks with the space, they are in for some incredible sonics.
Nice. What would be the minimum listening distance for 2 way horns that large to sum properly?
Approximately 2m (6.5').
We have a smaller horn we've been working on too. With wider directivity and will be combined with a 15" woofer in a vented enclosure. However, the design isn't ready yet. The midrange horn you see below is a prototype, but whether this will be the final design or not is uncertain.
I'll bring info about these speakers and also another speaker design when the time is ready in separate threads.
Very nice stuff! I love seeing horn stuff. I ran a tri-amp'd active X-over system with horns for years and I loved it.
@Bjorn I am in the process of building an upper-bass/lower midrange (150Hz - 1100Hz) horn, which is about 60 cm x 100cm at the mouth, using 3/4" MDF. I have found it to resonate too much for my liking. How do you make your large horn so that it does not color the sound by resonant vibrations? I can clearly hear mine resonating, albeit rarely. Thanks!
I'm afraid I can't assist you there since I'm doing this commercially. I'm sure you can get some valuable input at the DIY forum.
To bring the thread back on topic, I'll share a picture from my small home theater with an early CBT prototype we did.
No centre speaker...
What was shared in the beginning here: https://www.audiosciencereview.com/...sducer-cbt-speakers.12060/page-9#post-1392043
No real need. Mostly a one person home theater.
Would had to be a standing CBT behind the screen. A laying CBT center beats the purpose of the design
Or you can check out Monte Kay's CBT HT project -- for the center channel, click the "Center Speaker" button.
The reason is given in the center speaker page. Whether you agree with it or not is a separate question.
Measurement
Another aspect with a laying center is the loss of the doubling of the array and one will get a floor bounce besides a large amount of specular reflections from floor and ceiling unlike a standing CBT. It basically doesn't function as a CBT anymore. But looks cool though.