Well, you didn't specify the particulars of Harman's research but I have some random, somewhat disjointed thoughts.
My quickie summation is that Harman advocates 4th order crossovers which improves power handling and minimizes the possibility of breakups. To that we add a flat frequency response as well as uniform off-axis behavior. One can expand on that core by adding low distortion, good waterfalls, and so on. As I see it, that's pretty much what's trotted out there and what Olive blogs about. It's what he'll talk about if you catch him at a convention. From time to time he'll make a guest appearance at various websites and forums to draw attention to some work he's recently done much like a campaigner pressing the flesh during election season.
The idea in all of this is that is largely twofold. One, is that their studies using trained listeners and even untrained tend to support speakers that exemplify the above criteria are rated higher. Secondly, such speakers don't require anything additional in the way of room treatments since they've been tested in rooms which were designed to mimic what the average room has in the way of furnishings and acoustic properties. Just like the ubiquitous rotisserie sold by Ron Popeil, it's a set it and forget it approach.
Speaking strictly of pistonic speakers, this speaker design approach is embodied in Harman's top of the line Revel as well as the lower priced Infinity. AFAIK, if there's a trickle down effect to their other lower priced lines, I'm not aware of it and it doesn't seem to be promoted. The end result is we've got a bunch of other speakers that are OK.NAND some are more OK than others.
As I see it, the above is the public face of Harman's research. But I can't help that there's also a private side that's not disclosed. Is it bracing to move cabinet resonances to higher, less objectionable regions? Is it mitigation of the back wave, spreading out the back wave by radiusing the inside of the driver holes, is it, is it, is it?
Chef Morimoto can give you the ingredient list for one of his dishes but good luck trying to knock it out of the park like he does. So, I get the feeling, and it's just a feeling mind you, that the public, and for that matter some speaker designers, are being given just the basics.
I also have some reservations about their testing methods. Not so much the use of one speaker because it is more discriminating, but for other reasons.
One thing that troubles me is that in their testing facility, speakers are tested using a rapid switch shuttle system where each speaker is moved into the same location. From my POV, one needs to determine for themselves, what the optimum location and orientation of a speaker is in their own listening room. Might that change the rankings?
Dipoles, which Harman doesn't care for, need some room treatment above and beyond. The testing facility doesn't accommodate that.
Also, so long as Harman defines who their competitors are, B&W, Polk, Martin Logan, etc., it remains to be seen whether other brands like Paradigm, PSB, KEF, and various well regarded ID brands would score. Kind of like in Rocky III, when he realizes Mick has been picking easy fights.
And that's all I have to say about that.
