What is diffuse field equalization
Nov 14, 2002 at 7:42 PM Thread Starter Post #1 of 10

Kubernetes

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I've read in different places that some phones have it and some don't.

Can someone explain to me what it is exactly (and if you could put it in laymen's terms, that would be grand),

and which phones have it,

and how is it done?
 
Nov 14, 2002 at 9:52 PM Post #3 of 10
see the review of the dt770's a few lines down. also check the website for audio technica m40df headphones.

do a search for diffuse

diffuse field tries to mimick speakers (the angle of sound is overlapped).

diffuse field headphones are usually used by mixers and sound producers.
 
Nov 14, 2002 at 10:32 PM Post #4 of 10
To illustrate what diffuse field equalized means, it is perhaps better to explain first what free-field equalized means.

FREE-FIELD EQUALISATION
A standard for high-fidelity headphones endorsed by DIN, IEC and ANSI standardisation bodies during the 70's. Free field equalized headphone will try to achieve a similar frequency response as a perfectly flat frequency loudspeaker would do in an anechoic room (i.e. 'free field room').

Such a headphone will more than likely have a dip at 1200 Hz, a slow bump at c. 2000 Hz and another dip at c. 8000 - 10 000 Hz. The effect of this will be roughly flat frequency response at ear canal.

DIFFUSE-FIELD EQUALISATION
Another standard developed during the 80's to overcome the localisation problems in the mid-frequencies so apparent in free-field equalized headphones. It has not completely replaced free-field equalization, it's just another alternative (another design philosophy). Diffuse field equalized headphone will try to mimic a flat frequency loudspeaker response in a reverbant room that has equal sound pressure in most locations inside the room (i.e. diffuse field).

Such a headphone might have a different kind of frequency response, such as a peak at 2-3 kHz and 5-7 kHz and a sharper dip at 8 kHz. The effect should be similar to that of a diffuse field, but with a slightly different tonal balance.

Neither approach deliver FLAT frequency response for all (or even a majority of listeners) beyond 2000 Hz and certainly not beyond 8000 Hz.

In addition to the above there is a flat equalisation school of though that just delivers no equalisation like above.

All headphone manufacturers usually have some kind of ideal which they have experimentally found out in their own testing and most of their headphones follow this criteria.

In short, there is no single right way to do things and different people will find different equalisation 'natural' to them.

I hope that offers some little explanation.

regards,
Halcyon
 
Nov 30, 2010 at 9:15 PM Post #5 of 10
I have both an ED-1 and an ED-1 Signature.
I believe (though I will go about checking) that, as well as the equalisation of frequency response for diffuse field, there is some degree of cross feed of left to right and of right to left.
 
I can find this out easily enough when once I get these two machines out of storage....
 
Dec 1, 2010 at 9:46 AM Post #6 of 10
Nov 7, 2021 at 6:32 AM Post #7 of 10
Diffuse field headphones are my favourite kind. They are the one's that tend to sound the most natural, imo. I don't like headphones that follow the Harman Curve, they don't sound very natural to me and in fact some of the headphones i've heard that have it, sound too bassy for my liking. AKG K702 are my favourite diffuse field headphones, and that combined with the unique Varimotion diaphragm and flat wire voice coil are what gives it the sound I love and haven't found in any other headphone. That unique expansive soundstage, crisp clear treble and such well behaved, full, rounded bass response that behaves like the bass woofer of a well designed/engineered high end bookshelf speaker, full rounded with no hint of excess or weakness. Perfection.
 
Nov 7, 2021 at 6:40 AM Post #8 of 10
Or you could just take about any headphone and EQ it to Diffuse Field target curve :

Free-field-and-diffuse-field-frequency-responses-measured-with-HATS-Sound-source-is.png
 
Nov 7, 2021 at 7:15 AM Post #9 of 10
Yeah, I recently tried EQ software (Sonarworks) and was impressed by it, and might soon purchase it to use with my Sennheiser HD206, HD206 is pretty flat sounding to begin with though Sonarworks tames the treble a bit to bring it closer to their default target frequency response, which sounds very neutral indeed. I tried Sonarworks recently in an attempt to be open minded about EQ-ing headphones, but the truth is I am not a big fan of doing so. I think, when you EQ a headphone, you are not really changing the natural characteristics/sound of the drivers, you are merely altering the output levels of individual frequencies, like fooling around with the treble and bass tone controls of an integrated amplifier. It's not the same thing, imo. And with me being a purist, I prefer to hear the natural sound of everything, including speakers and headphones. And if I don't like the sound of a headphone, I will start modding it, applying physical changes to alter the sound, instead of EQ-ing it. That's just the way I like to approach it. I have never understood the fervent belief that EQ-ing heaphones makes any real difference, as opposed to modding them.
 
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Nov 8, 2021 at 7:49 AM Post #10 of 10
Yeah, I recently tried EQ software (Sonarworks) and was impressed by it, and might soon purchase it to use with my Sennheiser HD206, HD206 is pretty flat sounding to begin with though Sonarworks tames the treble a bit to bring it closer to their default target frequency response, which sounds very neutral indeed. I tried Sonarworks recently in an attempt to be open minded about EQ-ing headphones, but the truth is I am not a big fan of doing so. I think, when you EQ a headphone, you are not really changing the natural characteristics/sound of the drivers, you are merely altering the output levels of individual frequencies, like fooling around with the treble and bass tone controls of an integrated amplifier. It's not the same thing, imo. And with me being a purist, I prefer to hear the natural sound of everything, including speakers and headphones. And if I don't like the sound of a headphone, I will start modding it, applying physical changes to alter the sound, instead of EQ-ing it. That's just the way I like to approach it. I have never understood the fervent belief that EQ-ing heaphones makes any real difference, as opposed to modding them.
Modding and EQ are not equivalent. Therefore one can address issues the other can't and visa versa.

I've modded my HE-500 quite a bit. The well known "fuzzor" mod cuts serious issues of cancellation and reverberations - no EQ is ever going to fix that. OTOH, the 500 has two specific areas of notable ringing. A parametric EQ dialed in to the center of these issues and set for narrow is something a mod can't do w/o reducing a much wider frequency area.

In practice for me and 4 top cans is the mods are first and the EQ follows. I do not seek a flat curve, I just seek to add/subtract enough so that I am not distracted by it.

I do dislike intensely the bass settings of the sites that promote this "average room" "average listener" poppycock. Popularity has nothing to do with correct sound, and average rooms hold no interest for me having had or made excellent audio rooms for 35 years. Why one would want to dumb down a headphone to sounding like a speaker in a crap room is mystifying to me.

My 500 is better sounding for both EQ and Mods. It's probably a tribute to the junky pads/cables/screens HFM uses (round cups) that makes it easy to say that the mods are more important than the EQ. My HD-600 which is mildy modded and needs little EQ is made better by running on an OTL amp - dispense the mods and EQ both and the amp still dominates.

Basically every can is different, and understanding them (not just in a FR frame of reference) and then trying mods and EQ takes time, but can yield fine results. Although I wouldn't lay a hand on an 007, Voce, Susvara, etc. well maybe damp the headband or body (external)...
 

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