Constant Beamwidth Transducer (CBT) Speakers

[Newman]

Of course it functions like a CBT. It is a CBT.

In fact, if you take 'width' to mean side-to-side, this is the one with constant beamwidth, and the upright ones are not.

 

[svarteld]

I’m planning mounting my cbt36 in the roof, same position as I’ve used for floor. The roof is concrete and without obstructions, and I guess will make the mirror wavefront more coherent with the direct part, since floors usually have furniture obstructions and carpets. Any of you got some experience in this or advice?

thanks!

 

[Eurasian]

That actually sounds like a perfect application for a CBT

 

[brombo]

When you say roof I assume you mean ceiling. In the following link look at the fourth and fifth pictures from the top in the left hand column.

Don Keele CBT

Also look at attached picture.

 

[Bjorn]

Yes it will work as long as the ceiling is flat and the CBT is placed in the right direction.

We've considered designing a surround speaker for such a position. In terms of frequency response it would be the perfect position for a surround speaker but higher than what's ideal. For Atmos it would be great if one can live with the height of the speaker. A short CBT looses it's directivity earlier in frequency.

 

[svarteld]

Thanks for the comments! Sorry, ment "ceiling", the images show room and locations (black arcs in the living room). White boxes are the sub bass matrix (one more is added, now four).

I think CBTs in the favour of Don and Bjorn are the perfect everyday leisure-listening speakers, since thy actually work in a large room where you walk around, and can also be placed in positions that the usual omni-low/directional-high sounds really lousy, like my placements. Very girlfriend-friendly Roof-mounted, they also take up virtually no space.

Some think they're ugly. I'd like to make a case they're not. Adding some images from my previous apartment too. These should be a huge commercial success, if normal people ever got to listen to them. My girlfriends son have, he's 23, a typical "bass head", and listens mostly to electronic like techno; he's completely baffled and absorbed by the sound. They play these very transient tight artificial sounds in a way no other speakers I've heard; enormously wide, and tightly controlled, considering the listening space and placement.

I'll report how it goes

 

[brombo]

The CBT36 is perfect for an HTPC (I don't see the need for more than stereo). I will be upgrading by replacing the miniDSP openDRC-DA8 with a miniDSP Flex 8 with Dirac Live.

 

[laetoli37]

Thanks for the comments! Sorry, ment "ceiling", the images show room and locations (black arcs in the living room). White boxes are the sub bass matrix (one more is added, now four).

I think CBTs in the favour of Don and Bjorn are the perfect everyday leisure-listening speakers, since thy actually work in a large room where you walk around, and can also be placed in positions that the usual omni-low/directional-high sounds really lousy, like my placements. Very girlfriend-friendly Roof-mounted, they also take up virtually no space.

Some think they're ugly. I'd like to make a case they're not. Adding some images from my previous apartment too. These should be a huge commercial success, if normal people ever got to listen to them. My girlfriends son have, he's 23, a typical "bass head", and listens mostly to electronic like techno; he's completely baffled and absorbed by the sound. They play these very transient tight artificial sounds in a way no other speakers I've heard; enormously wide, and tightly controlled, considering the listening space and placement.

I'll report how it goes

View attachment 312567View attachment 312566View attachment 312565View attachment 312569View attachment 312568
View attachment 312570

I am very interested in how you will do the ceiling mounting. I have a pair of CBT24 that I may try ceiling installation one day !

 

[svarteld]

The CTB36 only requires two small distance pieces, and then using concrete expanders to go through the 8 mounting holes of the steel angled bracket for the elliptic foot stand, and instead into the concrete roof; no need for that foot stand when roof mounted. I've printed the distance pieces since they only see compression forces; if you'd like the 3d models, let me know.

 

[laetoli37]

The CTB36 only requires two small distance pieces, and then using concrete expanders to go through the 8 mounting holes of the steel angled bracket for the elliptic foot stand, and instead into the concrete roof; no need for that foot stand when roof mounted. I've printed the distance pieces since they only see compression forces; if you'd like the 3d models, let me know.

Wow, not for an amateur weekend DIY guy like me ! Do share pics when you are done . Thanks

 

[Bjorn]

Today I heard about the Børresen M6 speaker with a cost of $500,000. It's going to be demoed at a show in Norway soon and has caused a lot of discussion.

While it's certainly looks luxurious and probably has awesome painting finish I found it quite amusing to hear that it used 4.5" woofers!

That's actual the same woofer size we're using in a new CBT speaker but we have 18 pcs. Wonder what we should price the CBT speaker which also is wider with much lower baffle step and has a far more baffle free cabinet with no edges.

 

[Purité Audio]

Those sticks seem a bit random.
Keith

 

[thewas]

Those sticks seem a bit random.

Less random though than the price of that Børresen loudspeakers...

 

[RickS]

Looks too small to reside in, so as can have a really nice house for that sum, will wait for the bigger one!

 

[Spocko]

Those sticks seem a bit random.
Keith

They're only random until you realize that they cost $100 per stick as they absorb stray frequencies that diminish soundstage!

 

[Timcognito]

Surprised, no marks on the ceiling from hitting one's head. This place looks funky to me.

 

[Bjorn]

Is this a finish someone would like on the front panel of a CBT speaker?

The rest of the speaker would need to be painted because it curves in two dimensions. Could probably work well with both black and white painting.

 

[RickS]

Is this a finish someone would like on the front panel of a CBT speaker?
View attachment 354560

The rest of the speaker would need to be painted because it curves in two dimensions.

someone might, but I prefer black front baffles (notably if drivers are black too).

 

[Bjorn]

someone might, but I prefer black front baffles (notably if drivers are black too).

Ok. Drivers are black. That would imply black paint for all surfaces. Personally I like the contrast with veneer and paint, though I prefer matte veneer.

 

[Keith_W]

Reviving this topic. This is a screen cap from Don Keele's video showing the directivity of his CBT design:

Whilst it's undoubtedly cool looking, I would prefer to look at a polar response to see what it is actually doing.

But it got me wondering whether it would be possible to combine a waveguide or a horn with a CBT design to improve the horizontal dispersion characteristics. Is this another one of my stupid ideas, or does it have some merit?