A well mastered CD will sound good on any equipment designed to reproduce music properly.

omg,omg,omg. that's preposterous my good sir! everyone must have the big loud boom boom to sound hood yo.

actually, naw just playing. but,duh! a good sounding recording will sound good on everything as well, that's why my mind gets blown when lot of big time studio's resort to something like the loudness war. i mean if people don't care about the quality of sound in the first place then they wouldn't care what you did to it, and there forth should master it properly in the first place. people won't notice anyways.

Can we please fix the original post to reflect the (correct) idea that neutral is in fact a perfect reproduction (with respect to SPL) of real life?  And that a truly flat headphone is not at all close to reproducing real life? That is to say, a neutral at the ear, and not neutral at the speaker? (ie. a canalphone, headphone, speaker that sound of the same tonal balance, instead of a tonally balanced speaker, an extremely "dark" headphone and an even darker canalphone?).

The issue of equalisation was brought up quickly by khaos. While it can be confusing to consider that "flat" is NOT neutral until after HRTF and so on, it is correct to say so.

Here's a graph by Moller.
Black = The response required by a headphone to sound identical to a FLAT speaker (i.e. sound neutral) in a Free Field situation.
Blue - The response required by a headphone to sound identical to a FLAT speaker (i.e. sound neutral) in a diffuse field situation
Red is - The response required by a canalphone to sound identical to a FLAT speaker (i.e. sound neutral) in a diffuse field situation.

I've attached two graphs that were provided by manufacturers which reflect two different design ethics. One is a free field target curve by Stax, the other is a diffuse field curve target by Etymotic.


Every site on the planet perpetuates what I like to call The Flat Delusion, because they simply omit the information that headphones should not and do not measure flat. Ever.

While this may seem like a victimless crime, reporting neutral as flat (such as the manner in which Tyll does it), underrepresents a number of headphones with different design mechanics, due to the lack of standardisation of headphone response curves (which is addressed by Moller in the study that produced the graphs below). It is therefore, in the best interest that people learn to recognise these graphs, and then use them to modify on their own.

Consider for example, if a site decided to use an HRTF from a diffuse field for ALL of it's headphones. Using the graph provided by Stax, can we not see how the Lambda (pro and normal) pictured would be poorly represented, even though it does a very good job of free field equalisation? The stax design is slightly panoramic, creating a degree offset, theoretically similar to what you'd get with nearfield monitors. Meaning that, freefield is the CORRECT method to use in this case. How is it fair to judge all headphones by the same curve when no standard actually exists?


PS. I do not wish to endorse the graphs posted here as 100% accurate, even though I do believe they are relatively accurate.

This post should be a sticky. Too many people still get confused why neutral and natural on headphones don't necessarilly jive with each other at all times where with speakers, a neutral measurement almost always means natural. I say almost when talking about speakers because if other factors are highly flawed ex. distortion, impulse response, etc... then we wouldn't be sure if some factors that conbtributed to that flat response was the box making a certain resonance or some other anomaly. An example would be a driver that measured with a certain dip in reponse when mounted on a certain enclosure compensated with a peak at the same frequency with the ports resonant frequency, some box vibration or whatever else.

When talking about headphones... HRTF, measuring methods, etc. are extra factors making things more confusing as to whether a headphone is really neutral.

For what it's worth, I feel that the phrase "natural" has too much sway for personal taste.

I would prefer it if the accepted terms were FLAT to depict a speaker that outputs uniform sound energy (regarless of type), and NEUTRAL to reflect speakers that sound identical (in terms of frequency balance) at the ear.

In a perfect world though, neutral and natural should be synonyms unless a certain hearing impaired person needs a certain frequency response to compensate for their lack of hearing acuity in certain frequencies. This makes that specific transducer sound more natural to them than what they can actually hear in a live orchestral show for example

I disagree with your comments about hearing acuity. Large amounts of damage (for example to the treble region) has been directly linked to a problem called hyperacousis, which is in essense an over sensitivity to sound. It would actually be a bad idea to prescribe a bright headphone to someone with high frequency damage for music, as it is more likely to cause them discomfort. If for the purpose of understanding speech etc, it is probably a good idea to recommend a speaker/headphone with peaks at around 2khz and 6khz, to aid with diction, which is usually the first thing to go.

To consider your argument further; Neutral is neutral, under the model where neutral = exactly like real life. People with specific damage, experience that damage in all walks of life; at concerts, from a speaker, from headphones, during conversation. "FLAT" (for speakers) and "Neutral", for headphones are still the ideal, scientifically speaking. If you want to consider that someone might enjoy more treble due to hearing loss that's fine, however it imposes an ideal signature - which frankly doesn't exist (in objective terms).

One can argue however that neutral has no meaning for headphones. Many curves are based on averages, which means that it is not likely to be a perfect reproduction for you. Likewise if you have a particular issue (for example, if you have a missing ear/pinnae/have calcification in the ears), you may find it difficult to find an equal, centred sound, particularly for treble - which is much more easily effected because of the wavelength.