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Old 14th January 2013, 10:50 AM   #8071
DF96 is offline DF96  England
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F-M curves don't describe anyone's hearing. They describe the average of a large number of people. One may suppose that most people will have an individual curve which will not depart too far from the average, but without data this is speculation. Presumably they were obtained under circumstances designed to get the data they were after, so a direct read-across into domestic music listening may be unwise.

Our ears/brains adjust to the situation we are in. This adjustment aids listening to music, but would disrupt F-M type measurements so they may have taken steps to confuse the adjustment process. Therefore it is plausible to suggest that a loudness control need not modify the response as much as F-M would imply. The fact that such controls have been out of fashion for some time supports this; if they were essential they would be provided.

The situation could be looked at from the opposite point of view. At a particular volume level we are used to hearing sound with a particular frequency response. Artificially disturbing this volume/frequency association might create superficially clearer sound but with the risk of increased listening fatigue - it sounds 'unnatural'.
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Old 14th January 2013, 11:17 AM   #8072
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I recently bought a cheap Hitachi TV . I have a little FM transmitter and use headphones with it ( legal now ) . It sounds rather good and is available 2 streets away at 107.4 MHz ( careful what I watch , it was in French last night ) . Even with very comfortable but low grade headphones it outperforms the TV speakers . Like many TV's it has a built in graph equalizer . I have to say it turns dreadful into very usable . The curve chosen has a slight suck out at 1.5 kHz and boost to the bass in a nice curve . The upper bands I keep flat . One good test of a hi fi is that EQ doesn't make it better . I often build a slight EQ tweak into RIAA to allow 25 to 100 uS . It is so easy to do and will not screw up the circuit purity . My RIAA is active 3180 + 318 , passive 75 uS . Tweak-able 50 uS ( 75 uS ) in an FM turner might be useful . I want at some time to build an all passive RIAA/78 phono stage . Not because passive is best as I suspect what I do is the better way . No , because 78 EQ is then relatively easy . I did do one for my design . It took weeks to calculate how best to do all the active arrangements ( how to make it simple and accurate ) . The big surprise is proper 78 EQ makes a world of difference if the 78 has usable grooves ( Expert PU's make special styli to find un-played part sof the groove) . Wrong EQ is just that and seldom does any good except if Lo Fi or gross problems . Correct EQ is like colour adjustment , if can be stunningly different ( phase shift perhaps ? ) .

CURVES OF OLD RECORDS
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Old 14th January 2013, 12:37 PM   #8073
a.wayne is offline a.wayne  United States
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Originally Posted by dvv View Post
Gentlemen, thank you for your musings, but I'd like a straight yes or no answer.

Do you think Fletcher-Munson curves more or less precisely describe our hearing at lower and higher levels?

Talking about speaker linearity is truly evading the point, as its linearity is assumed. If it changes its tonal balance with changes of volume, then it hasn't been properly designed, something is amiss.

FYI my speakers do not change their tonal balance with change of volume, the louder it goes, the more of the same you get. Given the minscule dimensions of my room, they usually work at low levels.

Post 8034,8035.........
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Old 14th January 2013, 03:59 PM   #8074
RNMarsh is offline RNMarsh  United States
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Gentlemen, thank you for your musings, but I'd like a straight yes or no answer.

Do you think Fletcher-Munson curves more or less precisely describe our hearing at lower and higher levels?

.

No. It is One aspect.
-RNMarsh
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Old 14th January 2013, 04:14 PM   #8075
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No. It is One aspect.
-RNMarsh
Right. How people in experiments perceived sinusoidal sounds of different frequencies as equally loud. It does not answer the question, how to measure subjective ratio in loudness of 2 sounds. It may be easy to tell how close by loudness are 2 identical sounds to each other, but how to tell if they differ subjectively 2, or 3 times?
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Old 14th January 2013, 04:22 PM   #8076
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The fact that such controls have been out of fashion for some time supports this; if they were essential they would be provided.
It is the result of misunderstanding. If the amp sold with speakers, loudness compensation was used to extend bass region of that speakers on lower loudness, but with different speakers instead of extension it would boost bass that speakers already reproduce well. It is the difference, either supply extra power on low volume to boost 12 dB / Oct below Fs, or to boost bass on Fs and above.
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Old 14th January 2013, 06:29 PM   #8077
dvv is offline dvv  Serbia
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Still no answer, just more relativization, discovering of the obvious ...

Let me rephrase the question:

Do you think that Fletcher-Munson curves ROUGHLY approximate average human hearing related to change of volume?

Or, do you think that the average human hearing percieves the audio bandwidth 20-20,000 Hz differently at different volume levels?
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Old 14th January 2013, 06:47 PM   #8078
a.wayne is offline a.wayne  United States
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Shame on you D, pass the bottle thats must be some good stuff , you cant hear us ...

Or

Try ernest Rangling , below the bassline, tell me what you hear .....
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Old 14th January 2013, 08:07 PM   #8079
dvv is offline dvv  Serbia
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Shame on you D, pass the bottle thats must be some good stuff , you cant hear us ...

Or

Try ernest Rangling , below the bassline, tell me what you hear .....
Now, Wayne old buddy, no disrespect, but you should come around in September. That's when every self-respecting Serbian farmer makes his plum brandy. Legally, it's moonshine, but to them, it's a matter of prestige to make it as best they can. Putting anything in apart from plums and well water derogates their sliwowitz (from Serbian word "šljiva" (plum), derivative "šljivovica" meaning "made of plums") and of course, its maker. That would remind you of how the stuff tasted centuries ago, it's made in strictly traditional ways.

Too bad I don't touch the stuff, I'm strictly a beer man, with an occasional glass of wine, with fish, which is known to have to swim three times - one time in the sea or river, second time in vegetable oil and third time in good wine.

This is the kind of answer I get to my question.

Do you think FM curves depict one possible reality? You said you don't need any compensation - this may also be due to the fact that you have not tried using one with your current setup, and are therefore ignorant of possible benefits this might bring.

When I turn the loudness switch off in my Luxman preamp, I still hear the deep bass lines, but now they are dominated by the midrange, which due to my FM hearing, appears to be louder (more prominent) than the bass and extreme treble. I now have two choices. One is to crank up the volume to a point where it all appears in good proportion to me, and the other is to switch on the loudness function.

I am fortunate only insofar that this was really well done and well judged on the Luxman, because I have heard quite a bit of this function really smearing the overall sound on lesser devices, very similar to a run-off-the-mill, slap-it-together poorly designed tone control section.

How do I know which of the propotions is right? That goes back a long time, to my wild youth, when I sat on recording sessions on both sides, at the drums, or in the recording room. Therefore, I know EXACTLY how a drum set sounds and what its relative volume should be overall. Better than 99% of the people, even if I am a far cry from Billy Cobham.

However, to cut through the cheese (which is exactly what I'm doing now with some old Dutch cheese), it's perhaps best I end this discussion right now, as I have a nagging feeling many here would like to say that those FM curves are junk, but don't dare for some reason. I have no such problems, if science says something is so, and my ears tell me it ain't so, I'll flatly state that I think it ain't so.

I'll be the first to agree than in unfortunately too many cases the FM curves are overblown for immediate effect on a prospective buyer, but it's not the curves but their poor implementation at work.
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Old 14th January 2013, 08:12 PM   #8080
dvv is offline dvv  Serbia
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BTW, who's Ernest Rangling?

I don't recall ever hearing his name, but if he's into jazz, fusion or some such, no wonder I've never heard of him, I just plain hate jazz, fusion and such like.

I'm into as melodic as possible, things like Enya, Traveling Wilburies, Chris Isaac, etc. Just ordered these three from Amazon.com like 30 minutes ago.
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