HTRF is an extremely vast subject, probably a lot more complex and rich than building loudspeakers drivers.
https://www.bksv.com/media/doc/bn0221.pdf
Very informative report. I was wondering whether such information was available, thanks.
And I guess they differ not only for different angles but also for different source distances. With the ear partially covered by headphones the pinna will not have the same influence on the HRTF anymore like it would show with a source farther away.
So measuring in the ear canal with a tiny microphone would be the only accurate method for measuring the combined frequency response of an individuum and a specific headphone model. And there would still be room for errors like how to take into account the ear canal resonance......
Regards
Charles
This is what the NASA think about it... i'm joking.
In vivo measurements are a basic method, some brands like fit-ear make a negative mold that fits exactly (with the IEC711 volume taken in account i suppose) each customer ear canal, it is a shame that that coupler is not accurate at all in the treble.
https://www.itu.int/ITU-T/worksem/qos/200606/presentations/s3paper-rasmussen.pdf
Hope Im not too much disruption here but I've been reading and waiting for some time and now may be as good as any to throw this in the mix.
Ive been working on a smallish ribbon design for last 6 months. The goal was operation down to 1Khz. I dont want to go into the particulars about the diaphragm design BUT am at a crossroads with 2 versions of what is basically the same ribbon. One version keeps 2nd through 5th HD below about .5% across its working range. The other keeps 2nd,4th, and 5th at similar levels, but 3rd starts to rise below about 2khz to a level peaking to about 5%. Both measured at 90 db at 1 meter.
The "lower" distortion version has a sensitivity around 86 db, the "higher" distortion version has a sensitivity around 90db.
I bring this up because throughout this process I have been going back and forth about to death swapping the two designs in and out of a 2 way system to try and see if I can hear the difference.
I hate to admit this but I simply cannot hear a difference between the two. Ive tryed blind testing using my wife. She cannot tell a difference ether.
5% would likely get some negative press in the market. The 86 is useful in many systems but a 90 db sensitivity looks good on paper
.
Anyway I just throw that out as an example to chew on.
Ive been working on a smallish ribbon design for last 6 months. The goal was operation down to 1Khz. I dont want to go into the particulars about the diaphragm design BUT am at a crossroads with 2 versions of what is basically the same ribbon. One version keeps 2nd through 5th HD below about .5% across its working range. The other keeps 2nd,4th, and 5th at similar levels, but 3rd starts to rise below about 2khz to a level peaking to about 5%. Both measured at 90 db at 1 meter.
The "lower" distortion version has a sensitivity around 86 db, the "higher" distortion version has a sensitivity around 90db.
I bring this up because throughout this process I have been going back and forth about to death swapping the two designs in and out of a 2 way system to try and see if I can hear the difference.
I hate to admit this but I simply cannot hear a difference between the two. Ive tryed blind testing using my wife. She cannot tell a difference ether.
5% would likely get some negative press in the market. The 86 is useful in many systems but a 90 db sensitivity looks good on paper
.Anyway I just throw that out as an example to chew on.
I hate to admit this but I simply cannot hear a difference between the two. Ive tryed blind testing using my wife. She cannot tell a difference ether.
5% would likely get some negative press in the market. The 86 is useful in many systems but a 90 db sensitivity looks good on paper
Totally expected result for me. My choice should be obvious, the higher sensitivity. You can either play to the media or do the right thing, but you can't do both.
Agree.
My temptation was to offer both and explain ha.
Whats been interesting to me has been work on the rear chamber. I can easily hear the coloration's with different sizes/shapes/damping medium, but I cannot discern any difference between the two ribbons.
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Yes. IRCAM (where I used to work) has a whole library of HRTF measurements. You can find it online.
But I was curious about how the headphones are measured, as none of the headphones I've used that "sound flat" measure that way in any published plots I've seen. It would be nice to see what method was used to measure.
By "sound flat" I mean, of course, in general on music, but also if I set up a microphone in the room and compare live vs headphones. What I now have is almost identical between miked and live, at least for tonality. And I've also listened with sweeps to find any loud or soft spots on the headphones. I've used flat amplitude sweeps and sweeps EQ'd to match the equal loudness curves. Doing that, my headphones do need a little EQ at 2 points.
It would be nice to know what headphone measurement technique relates to my ears.
Here is a report that I did many years ago. It was confidential, but the time ran out. http://gedlee.azurewebsites.net/Papers/headphone_report.pdf
PS. I note that my conclusions were wrong in that I later found that VRTs do not always outperform moving coil. The Visang units that I love are moving coil!!!
PS. I note that my conclusions were wrong in that I later found that VRTs do not always outperform moving coil. The Visang units that I love are moving coil!!!
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That's easy: your perception (OK, maybe that's not a measurement of a headphone).
This discussion seems to think human perception is the same as a plastic dummy head, erroneously thinking if you can do the physics, hearing follows exactly.
Humans process the signal in all kinds of ways. Just one example is weird spatial localization you get with headphones but not speakers. Having something buzzing right in your ear certainly must call up peculiar perceptions or what psychologists call "equivalent stimulus" perceptions.
IRCAM... that's classy. Did you know Jean-Paul Risset who was a colleague of mine at Bell Labs?
B.
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Perception is complex, but it is also quantifiable, hence "If you do the physics, hearing follows."
I've also lost a lot of time by performing measurements in the near field (i've clearly underestimate the role of propagation
)Measurements are not repetable and inacurate in the circulating and propagating soup (with single microphone).
The far field and the near field are two different worlds.