• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Is the Harman target the most neutral headphone target?

Soria Moria

Senior Member
Joined
Mar 17, 2022
Messages
395
Likes
810
Location
Norway
Hi. In the headphone and IEM space I've noticed that people tend to refer to headphones with flat measuring bass as neutral, but from my own listening using Oratory's EQ presets on various headphones and the Quarks DSP, any headphone that alligns with the Harman target sounds a LOT more like a pair of reference speakers than any so-called 'neutral' headphone I've heard. Headphones I've owned and used that people have referred to as neutral and mixing headphones are ones such as HD800S and LCD-X, but both of these sound very coloured to me and I would definitely make a terrible sounding mix with them un-EQed.
 

GaryH

Major Contributor
Joined
May 12, 2021
Messages
1,348
Likes
1,804
I think it is well established that flat bass in a headphone or in-room response of a loudspeaker is NOT neutral. We’ve had trained listeners draw the perceived spectral balance of these targets and they are perceived as not flat.
Toole spent 10 years having listeners rate loudspeaker based on perceived fidelity/neutrality. When we switched to preference, the loudspeakers ratings didn’t suddenly change. There is a high correlation between fidelity/neutrality/ preference.

Our headphone targets do not deviate significantly above 200 Hz from a anechoically flat speaker measured in our reference room at the DRP. For the AE/OE target it’s within 2 dB of the bass of the in-room speaker target. For the IE target it’s higher, but there are data to support it needs to be higher to be perceived as equivalent
 

kemmler3D

Major Contributor
Forum Donor
Joined
Aug 25, 2022
Messages
3,022
Likes
5,632
Location
San Francisco
The harman curve(s) are meant to be neutral (compared to box speakers in-room) on average, but can't account for any quirks of your own HRTF or hearing in general. And it's hard to say whether any given headphone keeps to a given curve above 10khz (at best) anyway since measurements are not very reliable there. So IMO some EQ is probably necessary for everyone to get a neutral-to-them sound, but how exactly to achieve that is not super straightforward, since you have to rely on your ears to do it.
 

fpitas

Master Contributor
Forum Donor
Joined
Jul 7, 2022
Messages
9,885
Likes
14,191
Location
Northern Virginia, USA
Just like with speaker response, one size does not fit all. Some people like more bass. Some like less. Harman simply wanted a reasonable middle-of-the-road curve to make the most customers happy.
 

kemmler3D

Major Contributor
Forum Donor
Joined
Aug 25, 2022
Messages
3,022
Likes
5,632
Location
San Francisco
Just like with speaker response, one size does not fit all. Some people like more bass. Some like less. Harman simply wanted a reasonable middle-of-the-road curve to make the most customers happy.
With speaker response, you can at least be confident that the response of the speaker is what people hear. They come to the speaker with their entire HRTF intact.

With headphones, you're effectively attaching the driver to a custom-built horn with a microphone at the small end of it. You are not allowed to know the specifications of the horn in advance, just rough dimensions. So you don't know what any given person actually hears, let alone what they would PREFER to hear. Now, optimize the response at the microphone. ;)

The Harman curve does a good job outlining the average parameters of this "horn" but cannot account for every variant, that's up to the owner. :)

Someday I assume we will be able to get high-res laser scans that are used to generate personal FIRs for HRTF filtering and beyond... and all headphones can just be ruler-flat out of the box... until then you need to EQ with stock curves plus ears.
 

fpitas

Master Contributor
Forum Donor
Joined
Jul 7, 2022
Messages
9,885
Likes
14,191
Location
Northern Virginia, USA
With speaker response, you can at least be confident that the response of the speaker is what people hear. They come to the speaker with their entire HRTF intact.

With headphones, you're effectively attaching the driver to a custom-built horn with a microphone at the small end of it. You are not allowed to know the specifications of the horn in advance, just rough dimensions. So you don't know what any given person actually hears, let alone what they would PREFER to hear. Now, optimize the response at the microphone. ;)

The Harman curve does a good job outlining the average parameters of this "horn" but cannot account for every variant, that's up to the owner. :)
You're right about the wild card of your ear canal etc, but speakers get placed in rooms of all different types, too. In both cases some tweaking is a good idea if you want it just right for you.
 

kemmler3D

Major Contributor
Forum Donor
Joined
Aug 25, 2022
Messages
3,022
Likes
5,632
Location
San Francisco
You're right about the wild card of your ear canal etc, but speakers get placed in rooms of all different types, too. In both cases some tweaking is a good idea if you want it just right for you.
Correct about rooms. But if I am developing EQ curves... I'd rather deal with the acoustics of a large-ish rectangular prism than an ear... ;)
 

julian_hughes

Addicted to Fun and Learning
Joined
Aug 23, 2020
Messages
657
Likes
901
Hi. In the headphone and IEM space I've noticed that people tend to refer to headphones with flat measuring bass as neutral, but from my own listening using Oratory's EQ presets on various headphones and the Quarks DSP, any headphone that alligns with the Harman target sounds a LOT more like a pair of reference speakers than any so-called 'neutral' headphone I've heard. Headphones I've owned and used that people have referred to as neutral and mixing headphones are ones such as HD800S and LCD-X, but both of these sound very coloured to me and I would definitely make a terrible sounding mix with them un-EQed.
The Harman curve describes a statistical, aggregated listening *preference*. It's not an attempt to describe a neutral target.
 

dlaloum

Major Contributor
Joined
Oct 4, 2021
Messages
3,092
Likes
2,353
Read the quote I posted above from Dr Sean Olive.
If you go back to that thread (from which your quote came) - it is clear that Dr Olive was referring to work identifying PERCEPTION.

ie: most people's PERCEPTION of Neutral (which as we know, is impacted by sound levels and by loudness curves, etc...) - aligns with the Harman curve (as it was developed based on an average of the tested peoples perceptions!!

True Measurable "Neutrality" - is a whole different beast - and this is particularly indicated by Dr Olive's specific reference for a different curve when used for Binaural and/or HRTF purposes (where, I would suggest, true "measurable" neutrality" would be a requirement).

Also when considering that this therefore becomes a discussion about perceived neutrality, focusing on stereo recordings, listened to through headphones (without HRTF application...) - the volume level at which the listener chooses to use the headphones will in turn impact the listeners perception of neutrality as per the standard loudness perception curves...

Which of course implies, that different headphones will sound best at different volume levels - and that different users preferences, in terms of headphones, may also be driven by the levels at which they listen.

If you combine loudness curves, with a measurably flat/neutral headphone response - and set the listening level to the average used for the Harman tests that defined the Harman Curve.... do you end up with roughly the Harman Curve?
If not - then there is something else going on as well... if so then we have an understanding of what drives preferences, in a consistent system.
 

GaryH

Major Contributor
Joined
May 12, 2021
Messages
1,348
Likes
1,804
If you go back to that thread (from which your quote came) - it is clear that Dr Olive was referring to work identifying PERCEPTION.

ie: most people's PERCEPTION of Neutral (which as we know, is impacted by sound levels and by loudness curves, etc...) - aligns with the Harman curve (as it was developed based on an average of the tested peoples perceptions!!

True Measurable "Neutrality" - is a whole different beast - and this is particularly indicated by Dr Olive's specific reference for a different curve when used for Binaural and/or HRTF purposes (where, I would suggest, true "measurable" neutrality" would be a requirement).

Also when considering that this therefore becomes a discussion about perceived neutrality, focusing on stereo recordings, listened to through headphones (without HRTF application...) - the volume level at which the listener chooses to use the headphones will in turn impact the listeners perception of neutrality as per the standard loudness perception curves...

Which of course implies, that different headphones will sound best at different volume levels - and that different users preferences, in terms of headphones, may also be driven by the levels at which they listen.

If you combine loudness curves, with a measurably flat/neutral headphone response - and set the listening level to the average used for the Harman tests that defined the Harman Curve.... do you end up with roughly the Harman Curve?
If not - then there is something else going on as well... if so then we have an understanding of what drives preferences, in a consistent system.
Perceived neutrality is the only neutrality that matters.
 

kemmler3D

Major Contributor
Forum Donor
Joined
Aug 25, 2022
Messages
3,022
Likes
5,632
Location
San Francisco
Semantics, here:

Perceived neutrality = I am perceiving something that is known to be objectively neutral?

or

Perceived neutrality = I am perceiving something that is subjectively similar to something else that's objectively neutral?

or

Perceived neutrality = I am perceiving something that sounds subjectively neutral to me, without reference to objective neutrality?
 

dlaloum

Major Contributor
Joined
Oct 4, 2021
Messages
3,092
Likes
2,353
Semantics, here:

Perceived neutrality = I am perceiving something that is known to be objectively neutral?

or

Perceived neutrality = I am perceiving something that is subjectively similar to something else that's objectively neutral?

or


Perceived neutrality = I am perceiving something that sounds subjectively neutral to me, without reference to objective neutrality?
- Although there was mention of "experienced listeners" defining it as "neutral"

But as we already know, even experienced listeners can easily be tricked in double blind tests - with minor volume level variations
 
Top Bottom