Is this approach better than a coaxial speaker ?

[voodooless]

I have had this question bugging me for a while…what if you created a smooth waveguide using material that was semi-acoustically transparent. Screen material can be purchased with varying % opaqueness as one example.

Could midranges drive through such a screen, while the screen still maintains enough directivity control for the tweeter? A kind of co-entrant horn?

The problem is that the drivers have overlap. Even if you could make a material that would be opaque at some frequencies, you'll still need to deal with that area. If you had a material that behaves differently depending on the front or backside, you could do some really cool stuff though.

 

[TurtlePaul]

I have had this question bugging me for a while…what if you created a smooth waveguide using material that was semi-acoustically transparent. Screen material can be purchased with varying % opaqueness as one example.

Multi-entry horns and multi-diaphragm compression driver units have been done and work. I think the problem with the acoustic screen is that a standing wave is likely to form between the midrange driver and the portion of the screen which is reflecting back and also the midrange will be playing behind the tweeter at frequencies which are not low enough to wrap around the tweeter, damaging the dispersion and creating defraction effects. Also, significant absorbed sound will kill your speakers sensitivity rating.

 

[OWC]

I have had this question bugging me for a while…what if you created a smooth waveguide using material that was semi-acoustically transparent. Screen material can be purchased with varying % opaqueness as one example.

Could midranges drive through such a screen, while the screen still maintains enough directivity control for the tweeter? A kind of co-entrant horn?

Semi-acoustically transparent works two ways.
So there isn't really a waveguide either.
Unless you found a material that it does specifically for higher frequencies with a very sudden transition region.
We are talking about a region that is less than an octave or two.
Don't forget that the tweeter and woofer are doing frequencies that are in the same order of magnitude around the crossover region.

 

[fluid]

I have had this question bugging me for a while…what if you created a smooth waveguide using material that was semi-acoustically transparent. Screen material can be purchased with varying % opaqueness as one example.

Could midranges drive through such a screen, while the screen still maintains enough directivity control for the tweeter? A kind of co-entrant horn?

Not with fabric but PK Sound have quite an interesting solution in their Coherent Midrange Integrator.
http://pro-pa.com/index.php?id=2059

https://patents.google.com/patent/US9894433B2/en?oq=PATENT:+US9894433B2

 

[Plcamp]

PK Sound have quite an interesting solution

Cool, that is interesting. Pretty much everything one might imagine has been tried somewhere by somebody it seems!

 

[sarumbear]

Not with fabric but PK Sound have quite an interesting solution in their Coherent Midrange Integrator.
http://pro-pa.com/index.php?id=2059

https://patents.google.com/patent/US9894433B2/en?oq=PATENT:+US9894433B2

This is music to my ears. When was the last time you read similar from a Hi-Fi manufacturers?

To solve the problem, we applied a basic scientific method; define the problem, investigate all current approaches, propose a new solution, test the solution candidates through multiple iterations, and repeat the process until a solution was perfected. It was required to investigate and refine each part of the system to understand the complex interactions and dependencies, as each design decision relates to each other and the system as a whole.

PA speaker technology is miles ahead of Hi-Fi. Mainly because, audiphoolery simply cannot work; you can't convince tens of thousands of people in the hall/stadium with something actually fails to work. But also, the PA market size is orders of magnitude larger than Hi-Fi and this allows more R&D money.

 

[sarumbear]

Cool, that is interesting. Pretty much everything one might imagine has been tried somewhere by somebody it seems!

Every loudspeaker we use today has origins to a design from the 1930s. The industry had almost a century to iterate.