Not sure I like Harman curve

[krabapple]

These are excellent questions gents, and for a while I have been looking for a copy of the original paper published by the AES in 2014 and the follow-up study in 2019.

The AES page you link to has an option for you to purchase a copy of the 2014 paper. It's yours for $33.


And I'm guessing this is the 2019 paper

Cookie Absent

A decade or so of research summarized by Dr. Olive here

https://acousticstoday.org/wp-content/uploads/2022/03/The-Perception-and-Measurement-of-Headphone-Sound-Quality-What-Do-Listeners-Prefer-Sean-E.-Olive.pdf

From what I've read, Harman studies always exclude people with hearing loss.

 

[Lunafag]

Harman for Golden Ears Only?

Spoiler

 

[sejarzo]

Spoiler

View attachment 270124

Unsure how loss was compensated. My normal hearing is affected in the 6-8kHz range, but that's what I perceive to be normal and how I hear live acoustic music. Even so, the Harman curves for either in-ear or on-ear are obviously too bright for me with most recordings. They don't make music "sound like it used to" for me, not even close. I am surprised there isn't a bigger difference between "pop stereo" and "classical stereo".

 

[Lunafag]

the Harman curves for either in-ear or on-ear are obviously too bright for me with most recordings

Yeah I don't know what happened there. When determining the best sounding curve to me I end up with a whole 6dB less lower treble than Harman. More upper treble than Harman though.

 

[V17]

These are excellent questions gents, and for a while I have been looking for a copy of the original paper published by the AES in 2014 and the follow-up study in 2019. From what I know, they collected data from 238 participants of varying age, gender, and had a mixture of trained and untrained listeners in four countries. They were given a headphone with an approximation of the Harman curve and allowed to freely adjust bass and treble to their preference.

Imo this still raises the question "did they try using different corner frequencies for the bass & treble adjustments or not, and if not, how did they pick those frequencies?"

Considering that this is just a hobbyist question I'm not going to purchase papers from AES to see if they mention this. It is not mentioned in this summary pdf linked above. However what is shown in the pdf is that most headphones they tested, including those rated as "excellent", did not have the 250 Hz dip and instead seemed to roughly copy what seems to be my personal preference. Though the deviation seems to be centered around 200-230 Hz rather than 250 Hz, but that may be just my own imprecision, I did compensate for the dip only by ear and secondhand measurements.

You can see it here, the average frequency response (in blue) is relatively flat over the midbass region, so it deviates from the Harman target (in green):

Pretty interesting.

 

[sejarzo]

I have some concern about asking untrained listeners to adjust tone controls "to preference" because I know lots of presumably "untrained listeners" use ill-fitting earbuds or Beats over-ear headphones.

Google "headphone market share by brand" and you will find exactly what I expected to find.

This survey was run in 4 waves during 2022 among just under 5800 US headphone users:

 

[IAtaman]

So the one fix that I do when EQing headphones (which otherwise works tremendously well) is adding about 3 dB with Q=1 at 250 Hz. This is unrelated to the overall preferred amount of bass.

For me it is the opposite. I like the 200hz tuck of the Harman curve and add it with EQ if it is not there.

 

[V17]

I have some concern about asking untrained listeners to adjust tone controls "to preference" because I know lots of presumably "untrained listeners" use ill-fitting earbuds or Beats over-ear headphones.

They used a combination of trained and untrained listeners and there was a pretty strong correlation in preference between both groups. They did note a preference for more bass and slightly less for more treble in untrained listeners, as one would expect.

While undoubtedly most people uninterested in hifi listen to crappy headphones (though surprisingly this is slowly changing with bluetooth headphones which usually do internal EQ corrections), my experience with loudspeakers says that even random listeners recognize and appreciate high quality sound when they hear it - the trouble being that most of them have never heard it in their lives. So it is conceivable that when they do hear it with headphones, their judgement is not going to be terribly off on average.