Conventional loudspeakers have been with us since inventors Kellogg and Rice constructed the first moving coil drive unit out of empty Cornflakes packets back in the 1920s.
For all their problems, we stick with them. But that doesn't mean there are not alternatives. Take for example the mbl Radialstrahler.
It doesn't look like a loudspeaker, does it? The midrange and tweeter units are far removed from the old-fashioned box model.
“How do they work”, you ask. In simple terms, the Radialstrahler attempts to create the theoretical 'pulsating sphere' that a perfect loudspeaker would be.
A more-or-less standard loudspeaker motor drives an ovoid constructed from flexible, curved aluminum sections. Because they are flexible, they can pulse, thus creating sound waves.
Clever. But here's the really clever bit. Conventional loudspeakers suffer from being directional. The sound coming directly on-axis might sound great, but the further round to the side you go, the worse the sound gets. Distinctly worse.
Well, you might say, you don't listen from the side, you listen from in front. Yes you do, but you also hear sound from off-axis that has been reflected around the room. You can't get away from it. That is one of the reasons traditional loudspeakers sound as they do – like loudspeakers, and only vaguely like sounds generated by voices or musical instruments.
The Radialstrahler however, from low-mid to high frequencies, has distribution characteristics much closer to omnidirectional. So the sound that arrives at your ears through reflection is as good as the direct sound.
It's a great idea, not the only omnidirectional loudspeaker in the world but a great idea nonetheless.
You should book yourself a demonstration….
But bear in mind that a pair costs nearly $50,000!