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Should you use Fletcher-Munson loudness compensation?

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.:)
 
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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?
 
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.”
 
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.
 
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.
 
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

louf.jpg


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
 
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.
 
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:

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.
 
I love the Yamaha variable loudness control. It's just well done. :D 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?
 
Is it better to replace the loudness compensation function with the adjustment knob for high and low frequencies on the product?
no, then you have to change them every time you change the volume.
the loudness (if implemented right) switch should give you a volume dependent frequency curve adjustment.
(just like dynamic eq with audyssey)
 
no, then you have to change them every time you change the volume.
the loudness (if implemented right) switch should give you a volume dependent frequency curve adjustment.
(just like dynamic eq with audyssey)

Audyssey Dynamic EQ is quite limited compared to the RME ADI-2 "Loudness" feature. With Audyssey you have 4 Ref Level Offset settings that offer rather large leaps in-between them for managing bass response. 0dB, 5dB, 10dB and 15dB. That's it. Choose the one closest to your preference.

dq.png


Compare that to the ADI-2 "Loudness" feature that offers infinite settings. It's a HUGE upgrade.

rme.png


With RME ADI-2 app you control the exact amount of Bass and Treble boost as well as the volume level where it kicks in. This allows each speaker configured to have customized settings that sound the best with them rather than being limited to four presets. It opens up a whole new world of freedom not available to Audyssey gear. With this feature I can setup the Revel F328Be in one room and setup BMR Monitors in another room nearby (office) and tweak the BMR's with another ADI-2 DAC to sound very similar to the F328Be. This Loudness customization feature is an amazing tool and different speakers benefit from their own settings. I can't do this with my Denon 4700. It takes control to a new level. And if you want to hear the speaker without the Loudness feature simply turn it off/on with the remote for easy instant comparison.

Users that haven't learned how to customize the Loudness feature on the ADI-2 and experienced it's amazing sound tweaking ability probably think all DAC's sound the same. The ADI-2 "Loudness" customization can make a mild speaker THUMP like a pro or take a speaker that sounds distant and make it sound like you are in the front row. The speaker control you get with this option is like nothing else I have experienced. You get to have it your way. Instantly. No more screwing around trying different amps or DAC's to get a sound you want. The ADI-2 software lets you dial it in. It's the best audio tool I have. :D

22.png
 
no, then you have to change them every time you change the volume.
the loudness (if implemented right) switch should give you a volume dependent frequency curve adjustment.
(just like dynamic eq with audyssey)
But it only works effectively if you have an appropriate reference level - which movies do... and other sources don't.
 
Audyssey Dynamic EQ is quite limited compared to the RME ADI-2 "Loudness" feature. With Audyssey you have 4 Ref Level Offset settings that offer rather large leaps in-between them for managing bass response. 0dB, 5dB, 10dB and 15dB. That's it. Choose the one closest to your preference.

View attachment 378578

Compare that to the ADI-2 "Loudness" feature that offers infinite settings. It's a HUGE upgrade.

View attachment 378579

With RME ADI-2 app you control the exact amount of Bass and Treble boost as well as the volume level where it kicks in. This allows each speaker configured to have customized settings that sound the best with them rather than being limited to four presets. It opens up a whole new world of freedom not available to Audyssey gear. With this feature I can setup the Revel F328Be in one room and setup BMR Monitors in another room nearby (office) and tweak the BMR's with another ADI-2 DAC to sound very similar to the F328Be. This Loudness customization feature is an amazing tool and different speakers benefit from their own settings. I can't do this with my Denon 4700. It takes control to a new level. And if you want to hear the speaker without the Loudness feature simply turn it off/on with the remote for easy instant comparison.

Users that haven't learned how to customize the Loudness feature on the ADI-2 and experienced it's amazing sound tweaking ability probably think all DAC's sound the same. The ADI-2 "Loudness" customization can make a mild speaker THUMP like a pro or take a speaker that sounds distant and make it sound like you are in the front row. The speaker control you get with this option is like nothing else I have experienced. You get to have it your way. Instantly. No more screwing around trying different amps or DAC's to get a sound you want. The ADI-2 software lets you dial it in. It's the best audio tool I have. :D

View attachment 378582
Audyssey makes a new curve for each 0.5 dB volume step and the 4 levels are indeed offsets of the reference level that should be pretty precise for reference level material
Each step of 5 dB in offset will cause much smaller deltas in the corrections than that 5 dB, so I think you can be quite accurate in what you try to accomplish..

Also if you really think you know your offset wrt to reference level more accurate you could use the per input level offset to compensate even more accurate..
 
Audyssey makes a new curve for each 0.5 dB volume step and the 4 levels are indeed offsets of the reference level that should be pretty precise for reference level material
Mostly agree, The Audyssey DEQ is a pretty good implementation of the F-M curve idea.
My only complaint with it (as I mentioned before) is the way they decided to mess with the rear channels level.
AFAIK it has nothing to do with the F-M curve and their reason for doing it I've never found a straight answer on?
 
Is it better to replace the loudness compensation function with the adjustment knob for high and low frequencies on the product?

Everything old is new again ;>

What you ask about harkens back to the earliest days preamps/receivers, when they had a 'treble' and 'bass' knob (maybe a 'mid' knob too), but before they had a 'loudness' button.*

If that had been effective, there would have been no impetus to introduce a 'loudness' button.

What the treble/bass knobs were (still are, according to Floyd Toole) useful for, was compensating for differing treble/bass ratios in different recordings (which in turn stems from the whims/tastes/hearing being different in the different people recording and mixing, and them using different systems and monitoring --i.e., there being no standards for good audio recording).

But even with those adjustments, you're still subject to the Fletcher-Munson curve when output level changes.


*frankly I'm not sure when this period would be. When did 'loudness' buttons appear?
 
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