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Posts by JMS

Thanks for posting these comparison graphs, ultrabike. Do you have links to the original descriptions? I'd like to know whether smoothing was applied to them. My headphone graphs are unsmoothed, and look more like the ones you posted after 1/6 or 1/3 octave smoothing.
Ah, it's apparent that I need more clarification. The loudspeakers are set up in my living room for normal listening, forming an equilateral triangle with the listening seat about 7 feet on each side. The measurements from the "center" position are taken from the position of my listening seat. The "left" and "right" measurements are taken with the seat moved about 1.5 feet to the left and right respectively.   a) For measurements (a), I placed the microphone on a...
  It is to minimize the effects of comb filtering from reflections, diffraction, or other artifacts from the loudspeakers or the room. It is a standard technique used when measuring loudspeakers, such as in Stereophile's measurements.
My personal in-room HRTF frequency response is implied by the difference between the red curve (free standing) and green curve (in ear). Given that these two aren't spatially averaged curves, I wouldn't look too closely at small peaks and dips of low bandwidth. Looking at wholesale differences though, there does not appear to be any distinct peaks and dips of significance as in various standard HRTF curves. The only major difference I note is a broad boost of 2-5db from...
In the thread in this forum on the AES2012 paper about perception and measurement of headphone sound quality, I asked the Harman research team whether they have considered measuring desired headphone frequency response using loudspeaker playback on a dummy head as reference, similar to what is done by the Smyth Research Realiser A8.   Well, I've taken up the task myself, using binaural microphones in my own head, measuring in-room using Room EQ Wizard 5.0. The...
According to Harman's blind testing, #1 most revealing track is pink noise, and close behind is Tracy Chapman's "Fast Car".
Another question for Tonmeister and Meatus along the lines of "virtual" subjective testing:   Has there been thought given to measuring with a dummy head the response from loudspeaker playback, as a reference for desired frequency response? I know Harman uses a related technique to "virtualize" a vehicle's interior listening environment as a way to subjectively assess the vehicle's playback system, but what about the other way around? That is, to use Harman's own...
Finally got a chance to read the paper online at http://www.aes.org/e-lib/browse.cfm?elib=16446  This paper is a good step towards more subjective testing for headphones, which I think is really the right way to do science in this field.   My one comment would be that I wish the testing could have taken the "virtual" route as in cited work [9]. It appears that the authors' hypothesis had already been that frequency response (spectral balance) would be the most...
Tonmeister2008, will you be making a blog post about this work? I'm eagerly waiting to read the paper but I'm not sure when AES will have it online. Your blog posts have been great at making the science accessible to more people, both in terms of availability and understandability.
To clarify, it's currently assumed that an equalization curve (IEC 60268-7 or others) should be applied to a headphone's frequency response before interpretation. Innerfidelity.com's measurements are an example. This paper suggests otherwise.
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