‘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.

Teo wrote:

"And....digital room and digital speaker correction does not fix this.
"Does not fix this.
"Does not fix this."

Agreed!!

Nor can DEQ fix radiation pattern anomalies.  How many audio shows have you done where you spend three expensive days with the speakers fighting the room, and that battle overshadows pretty much everything else you had hoped to showcase? 

Imo acoustic problems can only be fixed in the acoustic domain, because otherwise they will inevitably be super-imposed atop any signal, whether that signal is EQ’d or not.

I think mainstream speaker design today is largely driven by marketing research, wherein the question "what do the people want in a speaker?" leads to acoustically-compromised narrow-footprint towers. Imo this is in part because "the people" usually don’t know any better, but SOME people (those blessed with two left ears come to mind) learn as they listen and put two-and-two together.

That’s actually okay with me - I’d much rather all those big companies with their big R&D departments and big budgets keep trying to make a flawed idea work well, and leave wide-body speakers to us little guys and the people out there who listen with their ears instead of their eyes.

Duke