‘modern’, ‘mainstream’ speakers—too many models converging towards too similar a sound

Kosst_amojan wrote: "I’ve never heard or read where anybody of authority suggested wide baffle speakers image as well or better than narrow to no baffle speakers. The unavoidably suffer from artifacts relating to edge diffusion and the more pronounced way in which the surface projects sound. It’s just the physics of the thing."

Roberjerman’s example of the Snell Type A is an excellent one. Imo Peter Snell’s approach made far more acoustic sense than any of these narrow-baffle tower speakers.

Here is why a wide baffle speaker can image as well or better than a narrow or "no baffle" speaker:

First, it’s not sound "projecting" off of a wide baffle that degrades imaging; it is the time delay between the direct sound and the arrival of the edge diffraction. Edge diffraction adds false early timing cues that can degrade the image. In general the longer the time delay (up to a point) before those false timing cues arrive, or in other words the wider the baffle, the worse the imaging degradation. BUT if we could significantly reduce edge diffraction, that would reduce these false timing cues to the point of being inconsequential, and imaging would correspondingly benefit. This can be done, but it requires either a very large-radius round-over (the technique Peter Snell used on the Type A), or aggressive absorption, or some other technique or combination of techniques.

None of these diffraction elimination techniques can be accomplished on a narrow baffle because the round-over or absorption or whatever has to be a sufficiently large fraction of a wavelength in order to be effective. Therefore if we are serious about eliminating diffraction, the cabinet width is going to be fairly substantial.

In practice the lowest diffraction enclosure would be precisely flush-mounted into the wall, which is the technique high-end recording studios use, resulting in a baffle the width of the room, along with superb imaging. There will still be a reflection when the sound reaches the sidewalls, but by then enough time has passed that the imaging will not be degraded significantly (I can go into more detail about the timing of reflections and/or diffraction if anyone is interested).

Duke

Thanks, guys, interesting discussion.

What I didn't put in the original post is that through this same experience I was also very impressed by three different speakers all of which could be considered to have wide baffles (certainly by modern standards).  Perhaps they weren't the ultimate imaging champs, but they were all more than sufficient in this regard, and other aspects of their acoustic profile were very compelling.

None of these diffraction elimination techniques can be accomplished on a narrow baffle because the round-over or absorption or whatever has to be a sufficiently large fraction of a wavelength in order to be effective. Therefore if we are serious about eliminating diffraction, the cabinet width is going to be fairly substantial.