I find the ‘open’ reproductive technology of speakers like the Magnepan and the Orion to be intriguing, but have listend to them only in environments that were too small, which I blame for the very disappointing sound I heard.

Loudspeakers that radiate both front and rear in basically opposite phase from each other would seem to be a contradiction. In an idealistic sense, who would ever think that would work? In the real world however, even a perfect speaker that would radiate sound in all directions perfectly in phase still exists in an environment where reflections and reverberations occur and arrive at the listener’s ears with a widely ranging mix of time delays. Even if the direct sound from the speaker is in phase, everything else is almost random. Place an opposing phase dipole acoustic radiator in the same reflective and reverberating environment and a curious thing happens. If the travel time of the reflections and reverberations from the rearward-radiating signal is large enough, the phase of the rearward sound, compared to the front-side sound, as it left the speaker is practically irrelevant. The ear-brain connection has already interpreted the front-side sound by the time most of the rearward sound has bounced and reached the listener. The rear-side sound, coming back with sufficient delay, adds to the feeling of spaciousness. A room large enough to allow for this may even ‘sound’ larger than it is.

But if the out-of-phase rearward sound is sent back toward the listener without sufficient delay in a room that is too small, or if the speakers are placed too near the walls, then significant amounts of some frequencies will be reinforced and others will suffer cancellation. This leads to what I call a ‘hollow’ sound where plenty of what should be there seems to be missing and some other things are over-emphasized – a cousin to the ‘boxy’ sound, this is the ‘open-air, hollow-box sound.’

While I appreciate the lauded reproduction of these types of loudspeaker, I’ve never had the environment available to make good use of them.