Tuberist, your Schweikerts are most definitely point source loudspeakers.
The vast majority of speakers are point source. How a speaker radiates into the environment has to do with the speaker's size in relation to the frequencies it is responsible for. The other major category of loudspeaker is "line source." Line source speakers are taller than the wavelength of the lowest frequency they are responsible for. Examples are speakers like Magneplanars, Sound Labs, Pipe Dreams and those big systems you see at stadium concerts.
Line Source speakers radiate acoustic energy into the environment more efficiently. Volume levels drop off at the cube of the distance with point source speakers but only at the square of the distance with Line source speakers. This is why line source speakers are used at big concerts.
The way line source speakers image is distinctly different. Point source speakers create a small image even if they are huge speakers. It is like sitting at the back of the concert hall. Line source speakers create a large image, like sitting up front. Some people think it is larger than life.
Line source speakers also have other advantages. They do not radiate up or down which helps limit room interactions. It you make them dipoles they do not radiate to the sides either.
The big disadvantage of line source speakers is size. For them to operate as line sources full range they have to be floor to ceiling tall. Most line sources sold for residential use are not full range. They convert to point source in the bass.
There are only two dynamic driver line source speakers that I know of, Bob Carver's Ultimate Line Source and a kit that Parts Express sells or was selling. They may both be out of production now. The Near Field Pipe Dreams are long gone. To do this with good drivers is a very expensive project. The tweeters have to be stacked very close together. The magnet structures are usually too big to allow this.
The vast majority of speakers are point source. How a speaker radiates into the environment has to do with the speaker's size in relation to the frequencies it is responsible for. The other major category of loudspeaker is "line source." Line source speakers are taller than the wavelength of the lowest frequency they are responsible for. Examples are speakers like Magneplanars, Sound Labs, Pipe Dreams and those big systems you see at stadium concerts.
Line Source speakers radiate acoustic energy into the environment more efficiently. Volume levels drop off at the cube of the distance with point source speakers but only at the square of the distance with Line source speakers. This is why line source speakers are used at big concerts.
The way line source speakers image is distinctly different. Point source speakers create a small image even if they are huge speakers. It is like sitting at the back of the concert hall. Line source speakers create a large image, like sitting up front. Some people think it is larger than life.
Line source speakers also have other advantages. They do not radiate up or down which helps limit room interactions. It you make them dipoles they do not radiate to the sides either.
The big disadvantage of line source speakers is size. For them to operate as line sources full range they have to be floor to ceiling tall. Most line sources sold for residential use are not full range. They convert to point source in the bass.
There are only two dynamic driver line source speakers that I know of, Bob Carver's Ultimate Line Source and a kit that Parts Express sells or was selling. They may both be out of production now. The Near Field Pipe Dreams are long gone. To do this with good drivers is a very expensive project. The tweeters have to be stacked very close together. The magnet structures are usually too big to allow this.