Sine sweeps are a good method to measure frequency response. That's what they were trying to do after all: measure frequency response. That was the stated goal of the test: find a correlation between frequency response and another parameter. They were playing a signal into a dummy, capturing the sound and measuring it; they were not trying to determine how pleased the dummy would be with the beautiful music.
However, I share your overall assessment that present-day transducers are far from perfect accuracy.
Sure, but the non-linear effects he's listing are probably not an issue for headphones. First, they're generally crossover-less and usually single-driver designs and they have very low moving mass which eliminates a host of issues that loudspeakers have. All those things are still there, and probably quantifiable, but I'd imagine that they're all low enough in headphones to be inaudible or 'not a problem.' What absolutely is a problem is manufacturer fuckery with frequency response ala 'megabass' and the like which is what really moves headphone sales. So it makes sense to me that that is what this study focuses on
> What absolutely is a problem is manufacturer fuckery with frequency response ala 'megabass'
Yep.
Now, that happens in any industry where consumers don't have an easy way to quantify what they're buying. TV screens in showrooms all have color saturation turned way up. Etc.
It should be said, however, that "megabass" or a V-shaped frequency response tends to be the case with intensely advertised, mass produced brands. The kind of stuff you find at Best Buy. It is much less of an issue, or not an issue at all, with brands aimed at people who pick transducers specifically for accurate sound.
E.g. I would expect to encounter "manufacturer fuckery" with Bose or Beats phones, and the like. I would not expect to encounter that with Sennheiser (at least their top models), AKG, Beyerdynamics, Audeze, Hifiman, Stax, Focal, Mr. Speakers, Oppo, etc. Okay, maybe a bit with Beyer. :)
That's not to say that some of these brands are not messing with the response at all. But when they do it, they do it in very subtle ways. The frequency response might be super-flat (or, rather, following the Harman curve which is appropriate for transducers placed on your ears). But they might "brighten" the sound a little, very subtly.
And then when another manufacturer comes along and says "screw those tricks, let's aim for perfect honesty instead", they sound a bit "veiled" in comparison. I'm talking about this in much greater detail here:
Anyway, we are still pretty far from perfect accuracy when it comes to transducers. All other parts of the audio chain have been figured out long ago. But transforming sound into electricity and vice-versa is still a hard problem.
Agreed, but I have returned a pair of sennheiser phones because they butchered the sound too much ... think it was one of the first in the momentum line if I recall
Well, when it comes to Sennheiser, there's the HD line and then there's everything else.
Even then, I think they really, really care about the HD600 / HD650 / HD800 succession of flagships. They might care a little bit about classic workhorses such as HD280 and the like. The rest I feel they are treating a bit more like crowdpleasers and moneymakers. I could be wrong.
It bothers me when they call them "monitors" and then go ahead and fiddle with the frequency response anyway. Look at the difference between the HD 280 pro and HD 380 pro, both labelled as monitoring headphones. The 380 sounds like a muddy mess in comparison, with everything below around 300hz turned up way too high. I think it's fair to ask: if you're going to make MegaBass headphones, mark them as such. Don't advertise flat response and then hand us this.
Sine sweeps are a good method to measure frequency response. That's what they were trying to do after all: measure frequency response. That was the stated goal of the test: find a correlation between frequency response and another parameter. They were playing a signal into a dummy, capturing the sound and measuring it; they were not trying to determine how pleased the dummy would be with the beautiful music.
However, I share your overall assessment that present-day transducers are far from perfect accuracy.