Should you use Fletcher-Munson loudness compensation?

[DanielT]

If you now have that function, loudness, on your amplifier, you just have to press the button and test. Not harder than that. If you like it or not depends on so many different factors so how can you be able to give advice about that to another person?

It even varies based on what music you, or at least I, listen to and what mood I am in. However, I think it is good to have that function, choice, loudness, on an amp.

Edit:
But as mentioned in the thread, different amplifiers have different EQ settings for loudness. You should of course investigate this if you are considering a new amp and if the loudness function is something you like. I suspect that loudness function does not have such a high priority in terms of the criteria you have when choosing an amplifier, but I may be wrong about that.

 

[PingWine]

I generated two filters that would transform a response that is flat at 80 Phon to flat at 60 Phon. Feel free to experiment.

View attachment 176274

With 85db being the reference in the movies, I think that 70db avg is as high I could go. How hard would it be to do a filter like you did for 85 -> 70?

 

[Dj7675]

With 85db being the reference in the movies, I think that 70db avg is as high I could go. How hard would it be to do a filter like you did for 85 -> 70?

Of note, that 85dB seems to be for large venue spaces. In the home you should be looking at 79dB-82dB as noted from Dolby HERE
”Each full-range speaker should be calibrated to produce the same C-weighted sound pressure level (SPL). The target SPL can range from 79 dB to 82 dB SPL(C) at the central listening position, depending on the room size, when driven with pink noise with an RMS level of ---20 decibels relative to full scale (dBFS).
Calibrate the subwoofer level to give the same level for redirected bass content from full- range speakers as those speakers produce in their pass bands. The target SPL can range from 79 dB to 82 dB SPL(C) at the central listening position, depending on the room size.”

 

[GalZohar]

Of note, that 85dB seems to be for large venue spaces. In the home you should be looking at 79dB-82dB as noted from Dolby HERE
”Each full-range speaker should be calibrated to produce the same C-weighted sound pressure level (SPL). The target SPL can range from 79 dB to 82 dB SPL(C) at the central listening position, depending on the room size, when driven with pink noise with an RMS level of ---20 decibels relative to full scale (dBFS).
Calibrate the subwoofer level to give the same level for redirected bass content from full- range speakers as those speakers produce in their pass bands. The target SPL can range from 79 dB to 82 dB SPL(C) at the central listening position, depending on the room size.”

I always wondered what was the logic/science behind that, could never find answers. This affects the amount of loudness compensation needed, although not really related to the main topic of "should you even use loudness compensation". Might justify its own thread if you have some kind of good explanation to reference.

 

[DonDish]

Via my ADI-2 PRO I use the progressive loudness constantly. One of the most innovative functions about the ADI´s. About processing in general I think its OK. A matter of taste, principle or whatever you would wanna put into it. One could discuss endlessly if its audiophile, kosher, what musicians wanted you to hear or whatnot. ,but in this age of digital I think we are moving past that. The DSProcess is so transparent now, and its becomming better and better. Its just natural evolution.

 

[dasdoing]

I don't know what Alexander Walsch did in his EQualizer-APO loudness correction module. It seams to compensate wrong:

here is his -20dB curve vs the one from AutoEQ, https://github.com/jaakkopasanen/AutoEq/blob/master/research/equal_loudness/70vs90_loudness.csv, which also matches this one, https://github.com/dpapavas/alsaloudness/blob/master/filterplots.png

now before you tell me that the EQ-APO one has 75dB as a reference, vs 90dB reference for the others, the deltas for the references in this range are very small: https://github.com/andrewjhunt/equal-loudness/blob/main/images/spl-deltas.png

also, and this is even worse: even though it seams to be possible to calibrate to 75dB and listen louder, it isn't. the flat point after calibration is always at 0dBFS....while it should be shiftet down to -20dBFS when you ajust your full loudness to 90dB for example

 

[dasdoing]

btw; was looking for alternative software solutions and found this analog one (might be intresting for someone): https://www.audioamp.eu/precise-stereo-logarithmic-loudness-23-step-stereo-attenuator-10-k/

 

[JoachimStrobel]

I just discovered this thread - sorry for being late
As in other posts I like to throw in the argument that all these loudness correction curves are very much age related. The current ISO stuff was measured with people in their 30’s. I came across one Japanese paper that compared loudness curves for all age groups and it is yaw dropping. People above 50-60 need a radical different curve. I may have to dig for that paper.
This is hard to swollow. Hence Denon and others will not add an elderly switch to their equipment as age does not sell. And we (I guess 90% of the audience here) can continue to dream.

 

[TimoJ]

I just discovered this thread - sorry for being late
As in other posts I like to throw in the argument that all these loudness correction curves are very much age related. The current ISO stuff was measured with people in their 30’s. I came across one Japanese paper that compared loudness curves for all age groups and it is yaw dropping. People above 50-60 need a radical different curve. I may have to dig for that paper.
This is hard to swollow. Hence Denon and others will not add an elderly switch to their equipment as age does not sell. And we (I guess 90% of the audience here) can continue to dream.

Was it this one:

https://www.researchgate.net/publication/270711273_Comparison_of_equal-loudness-level_contours_between_otologically_normal_young_and_older_adults

btw. Monoprice HTP-1 has two loudness modes, iso226 and vintage. And the "vintage" one has curve that has more treble and treble boost starts at a lower frequency.

 

[sarumbear]

I love the Yamaha variable loudness control. It's just well done. It can really transform a set of speakers into something else for awhile until the next setting comes down the pipe.

But isn’t that just a tone control?

 

[notsodeadlizard]

Well, of course, Lord!
Fletcher-Munson, Lord!
This is one of the funniest forums ever.

 

[JoachimStrobel]

Was it this one:

https://www.researchgate.net/publication/270711273_Comparison_of_equal-loudness-level_contours_between_otologically_normal_young_and_older_adults

btw. Monoprice HTP-1 has two loudness modes, iso226 and vintage. And the "vintage" one has curve that has more treble and treble boost starts at a lower frequency.

Cool free Publication. Says it all.