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Posts by JMS

  Only with (b) is the mic mounted in one ear. With (a) it's mounted on a tripod stand. In both cases a stereo sine sweep is played, so sounds from both loudspeakers are picked up by the mic. The difference between (a) and (b) is explained by what the head and torso do to the frequency response.
Let me add some more explanation as to what I'm trying to accomplish, which I really should have done in the initial post.   The motivation is to establish an ideal frequency response for headphones, in terms of subjective preference. For loudspeakers, we already have good research on what this response should be: when measured in-room, it's a flat line sloped downwards (see Floyd Toole's book on loudspeakers). Now, is there an equivalent statement that we can make...
Measurements of Sennheiser HD700 (yellow), HD650 (purple), and AKG K550 (green). The HD650 differs slightly from before because I remeasured to get a more consistent result.       These relative measurements are consistent with the general tonality that I hear from them. The HD700 sounds like the 650 but with more, over-emphasized lower midrange and bass. However, the HD700 overall still sounds significantly better than the HD650 to me. The HD650 sounds hollow...
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...
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