What's the benefit of this vs. using the the Klippel measurements? As Amir states (re: the Klippel measurement rig) in his speaker reviews:
The difference is that headphones are measured inside the ear. Whereas speakers usually are not.
So the microphone systems which are normally used for measuring the frequency response of a speaker will be missing all of the effects of the human body and the ear on the sound, before it actually reaches what is known as the ear drum reference point, or DRP (which is where most headphones are measured). This makes it much more difficult (but certainly not impossible) to do comparisons of, for example, the response of a good neutral loudspeaker in a room to a pair of headphones. To see if the latter is actually approximating something close to that speaker's in situ response.
One solution to this problem is to do measurements of the speakers in a room using the same kind of microphone system that is also used for doing headphone measurements. Which usually involves the use of a dummy head, with a mic installed inside the dummy's artificial ear at the DRP. This is the kind of setup which is shown in NTK's photo above.
Ideally this type of setup would also contain part of the dummy's torso as well, to capture some of the effects of a person's body on the speaker's sound field before it reaches the eardrum as well. But Tyll H. apparently didn't have one available for his system. So he used just the head and neck instead (which is all he used for making his headphone measurements).
There are some other methods of approximating a speaker's in-ear response than doing measurements from inside a dummy or human ear. (And Resolve actually mentions something about this in his stage 9 description in the video.)
One of the best and easiest methods of doing this, imho, is to simply combine the speaker's diffuse
sound power response (from its spinorama graph) with the diffuse field response of the rig or dummy head being used for the headphone measurements. Convincing people that a method like this can actually work, and yield a decent result requires some actual in-ear measurement data from the speakers for comparison though. Which is something we don't really have for most of the rigs which are currently in use for measuring headphones. (Seeing is believing, as they say.)
Though I can certainly identify with alot of what he's talkin about here. And I suspect some others here may as well. (Hence the reason for this post.)
