Equal-loudness contour - Wikipedia
Perceived discrepancies between early and more recent determinations led the International Organization for Standardization (ISO) to revise the standard curves in ISO 226. They did this in response to recommendations in a study coordinated by the Research Institute of Electrical Communication, Tohoku University, Japan. The study produced new curves by combining the results of several studies—by researchers in Japan, Germany, Denmark, UK, and USA. (Japan was the greatest contributor with about 40% of the data.)
This has resulted in the recent acceptance of a new set of curves standardized as ISO 226:2003. The report comments on the surprisingly large differences, and the fact that the original Fletcher-Munson contours are in better agreement with recent results than the Robinson-Dadson, which appear to differ by as much as 10–15 dB especially in the low-frequency region, for reasons not explained.
Very changing from an individual to another AND non-linear in amplitude.
That's a nice recipe for NOT having true Hi-Fi solutions for the next 1000 years.
That's a nice recipe for NOT having true Hi-Fi solutions for the next 1000 years.
Come on... It only means that for some people say 88 Db/w/m speakers with 40W amp are fine, when other person needs 200W with 105 dB/W/M speakers.
For both persons their system is "true solution".
The main reason for me, for going multiway is directivity control. By far the biggest improvement I've had to overall sound quality was when I went this route.
Realistically this is impossible to do with full range systems, but by their very nature they have limited off axis, high frequency, energy which will help to reduce early reflections and improve imaging. Having very wide dispersion is overrated and is detrimental for precise imaging unless you like the type of sound.
Of course you need to have high frequency extension up to the limits of your hearing otherwise you will notice a lack of sparkle. This is perhaps why some people find these systems more acceptable than others. Certainly I need smooth extension up to around 17khz, which is only really possible from the 2-4" class of full rangers.
With an LT to augment the bass, something like the SB65WBAC or the Scan 10F can sound utterly sublime when used nearfield in limited SPL applications. In fact, ignoring the obvious lack of sub bass they can have world class sound quality and neutrality, perfect for critical listening. This is where the party ends though, try and do anything else with just the single driver and you'll run into trouble.
This is not to say that you cannot get a room filling sound from the above, of course you can, depending on the size of your room, but nothing that's acceptable for true critical listening.
High passing the full range and adding in a bass driver would solve some of these issues. But now we're not single driver any more.
When done correctly I like full range and multiway, they each have their uses, strengths and weaknesses. It's best to use what makes the most sense from a system point of view.
Realistically this is impossible to do with full range systems, but by their very nature they have limited off axis, high frequency, energy which will help to reduce early reflections and improve imaging. Having very wide dispersion is overrated and is detrimental for precise imaging unless you like the type of sound.
Of course you need to have high frequency extension up to the limits of your hearing otherwise you will notice a lack of sparkle. This is perhaps why some people find these systems more acceptable than others. Certainly I need smooth extension up to around 17khz, which is only really possible from the 2-4" class of full rangers.
With an LT to augment the bass, something like the SB65WBAC or the Scan 10F can sound utterly sublime when used nearfield in limited SPL applications. In fact, ignoring the obvious lack of sub bass they can have world class sound quality and neutrality, perfect for critical listening. This is where the party ends though, try and do anything else with just the single driver and you'll run into trouble.
This is not to say that you cannot get a room filling sound from the above, of course you can, depending on the size of your room, but nothing that's acceptable for true critical listening.
High passing the full range and adding in a bass driver would solve some of these issues. But now we're not single driver any more.
When done correctly I like full range and multiway, they each have their uses, strengths and weaknesses. It's best to use what makes the most sense from a system point of view.
The bottomline is you can have an inner sensitivity @ 2.3khz while i do not.
Therefore, since we (humans) can usually detect differencials of about 0.3db or so, we might end up having very different perceptions on the very same sound system, listened at the very same spot.
How unprecise is that ''new-and-improved'' ISO 226:2003 ? I don't know. But it's sure an average no matter what. A Japanese-oriented average, it seems.
another thing about these studies...
HOW the subjects are communicating their sensations? Based on what, pain?
Pain is also relative.
The whole thing is very unprecise.
HOW the subjects are communicating their sensations? Based on what, pain?
Pain is also relative.
The whole thing is very unprecise.
So what?
Even sitting in the same philharmonic hall we hear differently. If the sound system fools imagination of both persons, as if it is "here and now", I see nothing wrong.
However, it is harder to fool my professionally trained imagination, since I hear distortions right away, but it is a different story...
Equal-loudness curves derived using headphones are valid only for the special case of what is called side-presentation, which is not how we normally hear. Real-life sounds arrive as planar wavefronts, if from a reasonably distant source. If the source of sound is directly in front of the listener, then both ears receive equal intensity, but at frequencies above about 1 kHz the sound that enters the ear canal is partially reduced by the masking effect of the head, and also highly dependent on reflection off the pinna (outer ear). Off-centre sounds result in increased head masking at one ear, and subtle changes in the effect of the pinna, especially at the other ear. This combined effect of head-masking and pinna reflection is quantified in a set of curves in three-dimensional space referred to as head-related transfer functions (HRTFs). Frontal presentation is now regarded as preferable when deriving equal-loudness contours, and the latest ISO standard is specifically based on frontal and central presentation.
The Robinson-Dadson determination used loudspeakers, and for a long time the difference from the Fletcher-Munson curves was explained partly on the basis that the latter used headphones. However, the ISO report actually lists the latter as using "compensated" headphones, though it doesn't make clear how Robinson-Dadson achieved that.
The Robinson-Dadson determination used loudspeakers, and for a long time the difference from the Fletcher-Munson curves was explained partly on the basis that the latter used headphones. However, the ISO report actually lists the latter as using "compensated" headphones, though it doesn't make clear how Robinson-Dadson achieved that.
"They saved (sic) lot of money by limiting phone communications bandwidth". Yeah?, and now we have telephone audio quality that resides at the very bottom, well below the likes of our Walkie-Talkies we played with in the sixties.
---------------------------------------------------------------Rick.............
---------------------------------------------------------------Rick.............
Right; now bandwidth is cheap, but think of 1930'Th when they paid real money for it!
What about reproduced sounds (music) ?
What about sound engineers that are also having those limitations (and equipement's limitations) ?
We all know how natural sounds sounds, but when the reproduction aspect enter the game, everything can happen. Especially trying to compensate for a bad recording.
Have I found a use for this otherwise useless contrivance? Equal Loudness Contour (and How to Use It) – Dustin M. Chaffin – Medium
It has nothing to do with Fletcher-Munson.
Pretty much any speaker sounds better to me once it gets a Watt or two compared to a few milliW regardless of resulting SPL.
Our hearing is really not to be trusted, the old objective vs. subjective arguement is no arguement...machines are our friend & colleague.
Neil deGrasse Tyson "We are poor data taking devices, that's why we have such a thing as science, because we have machines, that don't care what side of the bed they woke up on in the morning, don't care what they said to their spouse that day, don't care if they had their morning caffiene, they'll get the data right."
----------------------------------------------------------------------Rick............
Neil deGrasse Tyson "We are poor data taking devices, that's why we have such a thing as science, because we have machines, that don't care what side of the bed they woke up on in the morning, don't care what they said to their spouse that day, don't care if they had their morning caffiene, they'll get the data right."
----------------------------------------------------------------------Rick............
The history of this started with German radios that used excess power to extend bass response. If you boost frequencies below Fs 12 dB/Oct, you can get better bass when listening on low volume. It was misunderstood by some "too smart" engineer, then hi-fi systems started appearing with "loudness control" that tried to follow F-M curves that was totally wrong. 😀
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