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#42
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Stereo Loudness Control?
"Svante" wrote in message om... "Karl Uppiano" wrote in message . .. [snip my stuff] Good explanation, with one exception. The treble should NOT be turned up. It is commonly done with the loudness button, but there is no physiological excuse for doing so. Have a look at the Fletcher-Munson curves, eg at: http://www.webervst.com/fm.htm Now, the low frequencies are *compressed*, that is, moving 10 dB down may yield a perceived drop of 15-20 dB (or Phon to be absolutely correct). At mid and high frequencies a 10 dB drop will yield approximately a 10 dB perceived drop. The net result is that when the volume is turned down, the bass (only) appears to have dropped more than the mid and high. So, the treble should not be turned up, at least not for physiological reasons. Human hearing sensitivity isn't flat at any volume, but we do have a lower sensitivity threshold at the mid range than at the frequency extremes. The curves show a greater difference between mid-range and treble sensitivity at low volumes, although not as much greater as the difference between mid-range and bass. So some treble equalization is required. Loudness compensation as typically implemented (using only equalization) probably doesn't work very well because what is really needed is frequency-dependent dynamic range compression at lower volumes. I have a rather severe hearing loss centered on 4 kHz, so for improved intelligibility, if not concert hall realism, "My Loudness Setting" would need to keep a band of frequencies centered on 4 kHz above my sensitivity threshold as the loudness is reduced. My hearing looks nothing like Fletcher-Munson, and I suspect that is true for most people, especially as they age. |
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#43
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Stereo Loudness Control?
"Svante" wrote in message om... "Karl Uppiano" wrote in message . .. [snip my stuff] Good explanation, with one exception. The treble should NOT be turned up. It is commonly done with the loudness button, but there is no physiological excuse for doing so. Have a look at the Fletcher-Munson curves, eg at: http://www.webervst.com/fm.htm Now, the low frequencies are *compressed*, that is, moving 10 dB down may yield a perceived drop of 15-20 dB (or Phon to be absolutely correct). At mid and high frequencies a 10 dB drop will yield approximately a 10 dB perceived drop. The net result is that when the volume is turned down, the bass (only) appears to have dropped more than the mid and high. So, the treble should not be turned up, at least not for physiological reasons. Human hearing sensitivity isn't flat at any volume, but we do have a lower sensitivity threshold at the mid range than at the frequency extremes. The curves show a greater difference between mid-range and treble sensitivity at low volumes, although not as much greater as the difference between mid-range and bass. So some treble equalization is required. Loudness compensation as typically implemented (using only equalization) probably doesn't work very well because what is really needed is frequency-dependent dynamic range compression at lower volumes. I have a rather severe hearing loss centered on 4 kHz, so for improved intelligibility, if not concert hall realism, "My Loudness Setting" would need to keep a band of frequencies centered on 4 kHz above my sensitivity threshold as the loudness is reduced. My hearing looks nothing like Fletcher-Munson, and I suspect that is true for most people, especially as they age. |
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#44
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Stereo Loudness Control?
"Svante" wrote in message om... "Karl Uppiano" wrote in message . .. [snip my stuff] Good explanation, with one exception. The treble should NOT be turned up. It is commonly done with the loudness button, but there is no physiological excuse for doing so. Have a look at the Fletcher-Munson curves, eg at: http://www.webervst.com/fm.htm Now, the low frequencies are *compressed*, that is, moving 10 dB down may yield a perceived drop of 15-20 dB (or Phon to be absolutely correct). At mid and high frequencies a 10 dB drop will yield approximately a 10 dB perceived drop. The net result is that when the volume is turned down, the bass (only) appears to have dropped more than the mid and high. So, the treble should not be turned up, at least not for physiological reasons. Human hearing sensitivity isn't flat at any volume, but we do have a lower sensitivity threshold at the mid range than at the frequency extremes. The curves show a greater difference between mid-range and treble sensitivity at low volumes, although not as much greater as the difference between mid-range and bass. So some treble equalization is required. Loudness compensation as typically implemented (using only equalization) probably doesn't work very well because what is really needed is frequency-dependent dynamic range compression at lower volumes. I have a rather severe hearing loss centered on 4 kHz, so for improved intelligibility, if not concert hall realism, "My Loudness Setting" would need to keep a band of frequencies centered on 4 kHz above my sensitivity threshold as the loudness is reduced. My hearing looks nothing like Fletcher-Munson, and I suspect that is true for most people, especially as they age. |
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#45
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Stereo Loudness Control?
"Svante" wrote in message om... "Karl Uppiano" wrote in message . .. [snip my stuff] Good explanation, with one exception. The treble should NOT be turned up. It is commonly done with the loudness button, but there is no physiological excuse for doing so. Have a look at the Fletcher-Munson curves, eg at: http://www.webervst.com/fm.htm Now, the low frequencies are *compressed*, that is, moving 10 dB down may yield a perceived drop of 15-20 dB (or Phon to be absolutely correct). At mid and high frequencies a 10 dB drop will yield approximately a 10 dB perceived drop. The net result is that when the volume is turned down, the bass (only) appears to have dropped more than the mid and high. So, the treble should not be turned up, at least not for physiological reasons. Human hearing sensitivity isn't flat at any volume, but we do have a lower sensitivity threshold at the mid range than at the frequency extremes. The curves show a greater difference between mid-range and treble sensitivity at low volumes, although not as much greater as the difference between mid-range and bass. So some treble equalization is required. Loudness compensation as typically implemented (using only equalization) probably doesn't work very well because what is really needed is frequency-dependent dynamic range compression at lower volumes. I have a rather severe hearing loss centered on 4 kHz, so for improved intelligibility, if not concert hall realism, "My Loudness Setting" would need to keep a band of frequencies centered on 4 kHz above my sensitivity threshold as the loudness is reduced. My hearing looks nothing like Fletcher-Munson, and I suspect that is true for most people, especially as they age. |
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#46
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Stereo Loudness Control?
Rich Andrews wrote in message . 3.44...
(Svante) wrote in m: Rich Andrews wrote in message news: ... (Svante) wrote in om: "Karl Uppiano" wrote in message news: ... Loudness controls aren't meant to compensate for equipment deficiencies, but they are an attempt to compensate for the "Fletcher-Munson effect" in which our ears tend to become less sensitive to frequency extremes at low volume. Unfortunately, even the best analog loudness circuits only roughly approximate the right compensation. Also, no two people are alike, and furthermore, without separate loudness and volume controls, it's nearly impossible to calibrate the loudness compensation. Here's how it works: You turn the loudness control all the way up, then you turn up the volume control for the original sound pressure level (how would you know how loud the original recording was? That information is usually not provided). Then you use the loudness control to adjust for a comfortable listening level. With a single volume control, any loudness compensation simply assumes that the original sound pressure level is when the volume control is halfway up. When all is said and done, it's probably only slightly less convenient to just turn up the bass and treble when listening at low volume. Good explanation, with one exception. The treble should NOT be turned up. It is commonly done with the loudness button, but there is no physiological excuse for doing so. Have a look at the Fletcher-Munson curves, eg at: http://www.webervst.com/fm.htm Now, the low frequencies are *compressed*, that is, moving 10 dB down may yield a perceived drop of 15-20 dB (or Phon to be absolutely correct). At mid and high frequencies a 10 dB drop will yield approximately a 10 dB perceived drop. The net result is that when the volume is turned down, the bass (only) appears to have dropped more than the mid and high. So, the treble should not be turned up, at least not for physiological reasons. I quite disagree. Both the treble and bass are to be compensated if the end result is to be a flat response. The treble not as much as the bass, but it still needs to be done. http://members.aol.com/sbench/freqres3.html r That is just the point, the goal is NOT to acheive ears with a flat frequency response. Why would you want to listen with flat ears at home when you have the non-flat ears at every concert you go to? For example, the dip in the FM curves at ~3kHz comes from resonance in the earcanal outside the eardrum. Would you want to cancel the effect of the earcanal, just because you listen at home? The use of the loudness button can be explained by looking in detail at the FM curves, let's take the curves on the page you referred to. Let's also say that we play a piece at 50 dB level, but that the piece actually was recorded at 90 dB. Without any compensation this will happen: At 1kHz we will perceive a drop of 40 Phon, we pass four lines going downwards in the FM diagram. At low frequencies, say 100 Hz, we will perceive a drop of 70 Phon as we pass 7 lines. Boosting the bass, by 30 phon (about 20 dB at 100 Hz and this level) would give a listening impression more similar to the original recording. At 10 kHz we only pass 4 lines, ie we perceive a 40 Phon drop. Boosting the treble would (and does) yield an unnaturally bright sound. I shall admit that there IS a certain compression effect at the very highest levels at 10 kHz, between 100 and 120 dB we pass 3 Phon lines, and would perceive a 30 Phon change. However, the loudness function is hardly intended to compensate for these extremely high levels in the treble. Also going from 0 to 90 dB there IS a minimal compression of ~2dB, which is hardly worth compensating for. Did that explain my point? No. r So, do you not understand or do you think I am wrong? I am aware that each of the phon curves are non-flat, but it does not make sense to compensate for the curves themselves, since we use them in everyday life. The unnatural thing that is brought to us with the home stereo is that we can listen to something that was recorded at say 90 dB at 50 dB, and then we can use the loudness function to compensate for the DIFFERENCE between the phon curves for those levels. In the treble the DIFFERENCE between the curves is minimal, but in the bass the difference is large. Still no luck? |
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#47
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Stereo Loudness Control?
Rich Andrews wrote in message . 3.44...
(Svante) wrote in m: Rich Andrews wrote in message news: ... (Svante) wrote in om: "Karl Uppiano" wrote in message news: ... Loudness controls aren't meant to compensate for equipment deficiencies, but they are an attempt to compensate for the "Fletcher-Munson effect" in which our ears tend to become less sensitive to frequency extremes at low volume. Unfortunately, even the best analog loudness circuits only roughly approximate the right compensation. Also, no two people are alike, and furthermore, without separate loudness and volume controls, it's nearly impossible to calibrate the loudness compensation. Here's how it works: You turn the loudness control all the way up, then you turn up the volume control for the original sound pressure level (how would you know how loud the original recording was? That information is usually not provided). Then you use the loudness control to adjust for a comfortable listening level. With a single volume control, any loudness compensation simply assumes that the original sound pressure level is when the volume control is halfway up. When all is said and done, it's probably only slightly less convenient to just turn up the bass and treble when listening at low volume. Good explanation, with one exception. The treble should NOT be turned up. It is commonly done with the loudness button, but there is no physiological excuse for doing so. Have a look at the Fletcher-Munson curves, eg at: http://www.webervst.com/fm.htm Now, the low frequencies are *compressed*, that is, moving 10 dB down may yield a perceived drop of 15-20 dB (or Phon to be absolutely correct). At mid and high frequencies a 10 dB drop will yield approximately a 10 dB perceived drop. The net result is that when the volume is turned down, the bass (only) appears to have dropped more than the mid and high. So, the treble should not be turned up, at least not for physiological reasons. I quite disagree. Both the treble and bass are to be compensated if the end result is to be a flat response. The treble not as much as the bass, but it still needs to be done. http://members.aol.com/sbench/freqres3.html r That is just the point, the goal is NOT to acheive ears with a flat frequency response. Why would you want to listen with flat ears at home when you have the non-flat ears at every concert you go to? For example, the dip in the FM curves at ~3kHz comes from resonance in the earcanal outside the eardrum. Would you want to cancel the effect of the earcanal, just because you listen at home? The use of the loudness button can be explained by looking in detail at the FM curves, let's take the curves on the page you referred to. Let's also say that we play a piece at 50 dB level, but that the piece actually was recorded at 90 dB. Without any compensation this will happen: At 1kHz we will perceive a drop of 40 Phon, we pass four lines going downwards in the FM diagram. At low frequencies, say 100 Hz, we will perceive a drop of 70 Phon as we pass 7 lines. Boosting the bass, by 30 phon (about 20 dB at 100 Hz and this level) would give a listening impression more similar to the original recording. At 10 kHz we only pass 4 lines, ie we perceive a 40 Phon drop. Boosting the treble would (and does) yield an unnaturally bright sound. I shall admit that there IS a certain compression effect at the very highest levels at 10 kHz, between 100 and 120 dB we pass 3 Phon lines, and would perceive a 30 Phon change. However, the loudness function is hardly intended to compensate for these extremely high levels in the treble. Also going from 0 to 90 dB there IS a minimal compression of ~2dB, which is hardly worth compensating for. Did that explain my point? No. r So, do you not understand or do you think I am wrong? I am aware that each of the phon curves are non-flat, but it does not make sense to compensate for the curves themselves, since we use them in everyday life. The unnatural thing that is brought to us with the home stereo is that we can listen to something that was recorded at say 90 dB at 50 dB, and then we can use the loudness function to compensate for the DIFFERENCE between the phon curves for those levels. In the treble the DIFFERENCE between the curves is minimal, but in the bass the difference is large. Still no luck? |
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#48
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Stereo Loudness Control?
Rich Andrews wrote in message . 3.44...
(Svante) wrote in m: Rich Andrews wrote in message news: ... (Svante) wrote in om: "Karl Uppiano" wrote in message news: ... Loudness controls aren't meant to compensate for equipment deficiencies, but they are an attempt to compensate for the "Fletcher-Munson effect" in which our ears tend to become less sensitive to frequency extremes at low volume. Unfortunately, even the best analog loudness circuits only roughly approximate the right compensation. Also, no two people are alike, and furthermore, without separate loudness and volume controls, it's nearly impossible to calibrate the loudness compensation. Here's how it works: You turn the loudness control all the way up, then you turn up the volume control for the original sound pressure level (how would you know how loud the original recording was? That information is usually not provided). Then you use the loudness control to adjust for a comfortable listening level. With a single volume control, any loudness compensation simply assumes that the original sound pressure level is when the volume control is halfway up. When all is said and done, it's probably only slightly less convenient to just turn up the bass and treble when listening at low volume. Good explanation, with one exception. The treble should NOT be turned up. It is commonly done with the loudness button, but there is no physiological excuse for doing so. Have a look at the Fletcher-Munson curves, eg at: http://www.webervst.com/fm.htm Now, the low frequencies are *compressed*, that is, moving 10 dB down may yield a perceived drop of 15-20 dB (or Phon to be absolutely correct). At mid and high frequencies a 10 dB drop will yield approximately a 10 dB perceived drop. The net result is that when the volume is turned down, the bass (only) appears to have dropped more than the mid and high. So, the treble should not be turned up, at least not for physiological reasons. I quite disagree. Both the treble and bass are to be compensated if the end result is to be a flat response. The treble not as much as the bass, but it still needs to be done. http://members.aol.com/sbench/freqres3.html r That is just the point, the goal is NOT to acheive ears with a flat frequency response. Why would you want to listen with flat ears at home when you have the non-flat ears at every concert you go to? For example, the dip in the FM curves at ~3kHz comes from resonance in the earcanal outside the eardrum. Would you want to cancel the effect of the earcanal, just because you listen at home? The use of the loudness button can be explained by looking in detail at the FM curves, let's take the curves on the page you referred to. Let's also say that we play a piece at 50 dB level, but that the piece actually was recorded at 90 dB. Without any compensation this will happen: At 1kHz we will perceive a drop of 40 Phon, we pass four lines going downwards in the FM diagram. At low frequencies, say 100 Hz, we will perceive a drop of 70 Phon as we pass 7 lines. Boosting the bass, by 30 phon (about 20 dB at 100 Hz and this level) would give a listening impression more similar to the original recording. At 10 kHz we only pass 4 lines, ie we perceive a 40 Phon drop. Boosting the treble would (and does) yield an unnaturally bright sound. I shall admit that there IS a certain compression effect at the very highest levels at 10 kHz, between 100 and 120 dB we pass 3 Phon lines, and would perceive a 30 Phon change. However, the loudness function is hardly intended to compensate for these extremely high levels in the treble. Also going from 0 to 90 dB there IS a minimal compression of ~2dB, which is hardly worth compensating for. Did that explain my point? No. r So, do you not understand or do you think I am wrong? I am aware that each of the phon curves are non-flat, but it does not make sense to compensate for the curves themselves, since we use them in everyday life. The unnatural thing that is brought to us with the home stereo is that we can listen to something that was recorded at say 90 dB at 50 dB, and then we can use the loudness function to compensate for the DIFFERENCE between the phon curves for those levels. In the treble the DIFFERENCE between the curves is minimal, but in the bass the difference is large. Still no luck? |
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#49
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Stereo Loudness Control?
Rich Andrews wrote in message . 3.44...
(Svante) wrote in m: Rich Andrews wrote in message news: ... (Svante) wrote in om: "Karl Uppiano" wrote in message news: ... Loudness controls aren't meant to compensate for equipment deficiencies, but they are an attempt to compensate for the "Fletcher-Munson effect" in which our ears tend to become less sensitive to frequency extremes at low volume. Unfortunately, even the best analog loudness circuits only roughly approximate the right compensation. Also, no two people are alike, and furthermore, without separate loudness and volume controls, it's nearly impossible to calibrate the loudness compensation. Here's how it works: You turn the loudness control all the way up, then you turn up the volume control for the original sound pressure level (how would you know how loud the original recording was? That information is usually not provided). Then you use the loudness control to adjust for a comfortable listening level. With a single volume control, any loudness compensation simply assumes that the original sound pressure level is when the volume control is halfway up. When all is said and done, it's probably only slightly less convenient to just turn up the bass and treble when listening at low volume. Good explanation, with one exception. The treble should NOT be turned up. It is commonly done with the loudness button, but there is no physiological excuse for doing so. Have a look at the Fletcher-Munson curves, eg at: http://www.webervst.com/fm.htm Now, the low frequencies are *compressed*, that is, moving 10 dB down may yield a perceived drop of 15-20 dB (or Phon to be absolutely correct). At mid and high frequencies a 10 dB drop will yield approximately a 10 dB perceived drop. The net result is that when the volume is turned down, the bass (only) appears to have dropped more than the mid and high. So, the treble should not be turned up, at least not for physiological reasons. I quite disagree. Both the treble and bass are to be compensated if the end result is to be a flat response. The treble not as much as the bass, but it still needs to be done. http://members.aol.com/sbench/freqres3.html r That is just the point, the goal is NOT to acheive ears with a flat frequency response. Why would you want to listen with flat ears at home when you have the non-flat ears at every concert you go to? For example, the dip in the FM curves at ~3kHz comes from resonance in the earcanal outside the eardrum. Would you want to cancel the effect of the earcanal, just because you listen at home? The use of the loudness button can be explained by looking in detail at the FM curves, let's take the curves on the page you referred to. Let's also say that we play a piece at 50 dB level, but that the piece actually was recorded at 90 dB. Without any compensation this will happen: At 1kHz we will perceive a drop of 40 Phon, we pass four lines going downwards in the FM diagram. At low frequencies, say 100 Hz, we will perceive a drop of 70 Phon as we pass 7 lines. Boosting the bass, by 30 phon (about 20 dB at 100 Hz and this level) would give a listening impression more similar to the original recording. At 10 kHz we only pass 4 lines, ie we perceive a 40 Phon drop. Boosting the treble would (and does) yield an unnaturally bright sound. I shall admit that there IS a certain compression effect at the very highest levels at 10 kHz, between 100 and 120 dB we pass 3 Phon lines, and would perceive a 30 Phon change. However, the loudness function is hardly intended to compensate for these extremely high levels in the treble. Also going from 0 to 90 dB there IS a minimal compression of ~2dB, which is hardly worth compensating for. Did that explain my point? No. r So, do you not understand or do you think I am wrong? I am aware that each of the phon curves are non-flat, but it does not make sense to compensate for the curves themselves, since we use them in everyday life. The unnatural thing that is brought to us with the home stereo is that we can listen to something that was recorded at say 90 dB at 50 dB, and then we can use the loudness function to compensate for the DIFFERENCE between the phon curves for those levels. In the treble the DIFFERENCE between the curves is minimal, but in the bass the difference is large. Still no luck? |
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#51
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Stereo Loudness Control?
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#52
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Stereo Loudness Control?
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#53
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Stereo Loudness Control?
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#54
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Stereo Loudness Control?
"Karl Uppiano" wrote in message ...
"Svante" wrote in message om... "Karl Uppiano" wrote in message . .. [snip my stuff] Good explanation, with one exception. The treble should NOT be turned up. It is commonly done with the loudness button, but there is no physiological excuse for doing so. Have a look at the Fletcher-Munson curves, eg at: http://www.webervst.com/fm.htm Now, the low frequencies are *compressed*, that is, moving 10 dB down may yield a perceived drop of 15-20 dB (or Phon to be absolutely correct). At mid and high frequencies a 10 dB drop will yield approximately a 10 dB perceived drop. The net result is that when the volume is turned down, the bass (only) appears to have dropped more than the mid and high. So, the treble should not be turned up, at least not for physiological reasons. Human hearing sensitivity isn't flat at any volume, but we do have a lower sensitivity threshold at the mid range than at the frequency extremes. The curves show a greater difference between mid-range and treble sensitivity at low volumes, They do? For example, look at: http://www.webervst.com/fm.htm Specifically look at 1kHz 0 phon and then go to 10 kHz 0 phon, 10 dB difference, right? Then 1kHz 30 phon and go to 10 kHz, 10 dB difference again. To my eye, all phon curves look nearly identical above 1 kHz up to 90 phon. So, IMO there is little compression in the treble, and little need for a treble boost as part of a loudness function. although not as much greater as the difference between mid-range and bass. So some treble equalization is required. Loudness compensation as typically implemented (using only equalization) probably doesn't work very well because what is really needed is frequency-dependent dynamic range compression at lower volumes. That is an interesting thought, to keep the really weak sounds from getting below the hearing threshold. Hmm... Might be practical, but hardly hifidilistic, but so isn't the loudness button in the first place. :-) |
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#55
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Stereo Loudness Control?
"Karl Uppiano" wrote in message ...
"Svante" wrote in message om... "Karl Uppiano" wrote in message . .. [snip my stuff] Good explanation, with one exception. The treble should NOT be turned up. It is commonly done with the loudness button, but there is no physiological excuse for doing so. Have a look at the Fletcher-Munson curves, eg at: http://www.webervst.com/fm.htm Now, the low frequencies are *compressed*, that is, moving 10 dB down may yield a perceived drop of 15-20 dB (or Phon to be absolutely correct). At mid and high frequencies a 10 dB drop will yield approximately a 10 dB perceived drop. The net result is that when the volume is turned down, the bass (only) appears to have dropped more than the mid and high. So, the treble should not be turned up, at least not for physiological reasons. Human hearing sensitivity isn't flat at any volume, but we do have a lower sensitivity threshold at the mid range than at the frequency extremes. The curves show a greater difference between mid-range and treble sensitivity at low volumes, They do? For example, look at: http://www.webervst.com/fm.htm Specifically look at 1kHz 0 phon and then go to 10 kHz 0 phon, 10 dB difference, right? Then 1kHz 30 phon and go to 10 kHz, 10 dB difference again. To my eye, all phon curves look nearly identical above 1 kHz up to 90 phon. So, IMO there is little compression in the treble, and little need for a treble boost as part of a loudness function. although not as much greater as the difference between mid-range and bass. So some treble equalization is required. Loudness compensation as typically implemented (using only equalization) probably doesn't work very well because what is really needed is frequency-dependent dynamic range compression at lower volumes. That is an interesting thought, to keep the really weak sounds from getting below the hearing threshold. Hmm... Might be practical, but hardly hifidilistic, but so isn't the loudness button in the first place. :-) |
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#56
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Stereo Loudness Control?
"Karl Uppiano" wrote in message ...
"Svante" wrote in message om... "Karl Uppiano" wrote in message . .. [snip my stuff] Good explanation, with one exception. The treble should NOT be turned up. It is commonly done with the loudness button, but there is no physiological excuse for doing so. Have a look at the Fletcher-Munson curves, eg at: http://www.webervst.com/fm.htm Now, the low frequencies are *compressed*, that is, moving 10 dB down may yield a perceived drop of 15-20 dB (or Phon to be absolutely correct). At mid and high frequencies a 10 dB drop will yield approximately a 10 dB perceived drop. The net result is that when the volume is turned down, the bass (only) appears to have dropped more than the mid and high. So, the treble should not be turned up, at least not for physiological reasons. Human hearing sensitivity isn't flat at any volume, but we do have a lower sensitivity threshold at the mid range than at the frequency extremes. The curves show a greater difference between mid-range and treble sensitivity at low volumes, They do? For example, look at: http://www.webervst.com/fm.htm Specifically look at 1kHz 0 phon and then go to 10 kHz 0 phon, 10 dB difference, right? Then 1kHz 30 phon and go to 10 kHz, 10 dB difference again. To my eye, all phon curves look nearly identical above 1 kHz up to 90 phon. So, IMO there is little compression in the treble, and little need for a treble boost as part of a loudness function. although not as much greater as the difference between mid-range and bass. So some treble equalization is required. Loudness compensation as typically implemented (using only equalization) probably doesn't work very well because what is really needed is frequency-dependent dynamic range compression at lower volumes. That is an interesting thought, to keep the really weak sounds from getting below the hearing threshold. Hmm... Might be practical, but hardly hifidilistic, but so isn't the loudness button in the first place. :-) |
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#57
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Stereo Loudness Control?
"Karl Uppiano" wrote in message ...
"Svante" wrote in message om... "Karl Uppiano" wrote in message . .. [snip my stuff] Good explanation, with one exception. The treble should NOT be turned up. It is commonly done with the loudness button, but there is no physiological excuse for doing so. Have a look at the Fletcher-Munson curves, eg at: http://www.webervst.com/fm.htm Now, the low frequencies are *compressed*, that is, moving 10 dB down may yield a perceived drop of 15-20 dB (or Phon to be absolutely correct). At mid and high frequencies a 10 dB drop will yield approximately a 10 dB perceived drop. The net result is that when the volume is turned down, the bass (only) appears to have dropped more than the mid and high. So, the treble should not be turned up, at least not for physiological reasons. Human hearing sensitivity isn't flat at any volume, but we do have a lower sensitivity threshold at the mid range than at the frequency extremes. The curves show a greater difference between mid-range and treble sensitivity at low volumes, They do? For example, look at: http://www.webervst.com/fm.htm Specifically look at 1kHz 0 phon and then go to 10 kHz 0 phon, 10 dB difference, right? Then 1kHz 30 phon and go to 10 kHz, 10 dB difference again. To my eye, all phon curves look nearly identical above 1 kHz up to 90 phon. So, IMO there is little compression in the treble, and little need for a treble boost as part of a loudness function. although not as much greater as the difference between mid-range and bass. So some treble equalization is required. Loudness compensation as typically implemented (using only equalization) probably doesn't work very well because what is really needed is frequency-dependent dynamic range compression at lower volumes. That is an interesting thought, to keep the really weak sounds from getting below the hearing threshold. Hmm... Might be practical, but hardly hifidilistic, but so isn't the loudness button in the first place. :-) |
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#58
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Stereo Loudness Control?
Per Stromgren wrote in message . ..
On 10 Feb 2004 03:48:55 -0800, (Svante) wrote: So, do you not understand or do you think I am wrong? I am aware that each of the phon curves are non-flat, but it does not make sense to compensate for the curves themselves, since we use them in everyday life. The unnatural thing that is brought to us with the home stereo is that we can listen to something that was recorded at say 90 dB at 50 dB, and then we can use the loudness function to compensate for the DIFFERENCE between the phon curves for those levels. In the treble the DIFFERENCE between the curves is minimal, but in the bass the difference is large. Do you have access to the numbers that make up the FM diagram so that we could compute the differences and close this, once and for all? I am aware that the curves may include tolerances, but so should the difference numbers that comes out of this. I remember vaguely trying to get these numbers, but the best I found was someone having traced the diagrams. Sorry. Could you fix this? Designing a loudness compensation circuit based on this would be trivial, at least in the digital domain, and it's only drawback would be the difficulty in setting the original venue loudness. ....and the efficiency of the loudspeakers, power amp gain, room reverberation radius, etc. But of course, these could be measured, You are right in that the level of the original recording is the toughest one to estimate. There are other issues as well, like that the FM curves are measured with sinusoidal sounds. There are effects, like masking and such, that will make an exact compensation difficult. I recall that this was my reason to give up digging for the FM numbers the last time, they would not do what I wanted since I used complex sounds (not sinusoiuds). Per, E-73 at KTH and a big fan of mr Fant and pip-Johan. Yes, aren't they great? Svante, E-85 at KTH and a big fan of mr Fant and pip-Johan. |
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Stereo Loudness Control?
Per Stromgren wrote in message . ..
On 10 Feb 2004 03:48:55 -0800, (Svante) wrote: So, do you not understand or do you think I am wrong? I am aware that each of the phon curves are non-flat, but it does not make sense to compensate for the curves themselves, since we use them in everyday life. The unnatural thing that is brought to us with the home stereo is that we can listen to something that was recorded at say 90 dB at 50 dB, and then we can use the loudness function to compensate for the DIFFERENCE between the phon curves for those levels. In the treble the DIFFERENCE between the curves is minimal, but in the bass the difference is large. Do you have access to the numbers that make up the FM diagram so that we could compute the differences and close this, once and for all? I am aware that the curves may include tolerances, but so should the difference numbers that comes out of this. I remember vaguely trying to get these numbers, but the best I found was someone having traced the diagrams. Sorry. Could you fix this? Designing a loudness compensation circuit based on this would be trivial, at least in the digital domain, and it's only drawback would be the difficulty in setting the original venue loudness. ....and the efficiency of the loudspeakers, power amp gain, room reverberation radius, etc. But of course, these could be measured, You are right in that the level of the original recording is the toughest one to estimate. There are other issues as well, like that the FM curves are measured with sinusoidal sounds. There are effects, like masking and such, that will make an exact compensation difficult. I recall that this was my reason to give up digging for the FM numbers the last time, they would not do what I wanted since I used complex sounds (not sinusoiuds). Per, E-73 at KTH and a big fan of mr Fant and pip-Johan. Yes, aren't they great? Svante, E-85 at KTH and a big fan of mr Fant and pip-Johan. |
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Stereo Loudness Control?
Per Stromgren wrote in message . ..
On 10 Feb 2004 03:48:55 -0800, (Svante) wrote: So, do you not understand or do you think I am wrong? I am aware that each of the phon curves are non-flat, but it does not make sense to compensate for the curves themselves, since we use them in everyday life. The unnatural thing that is brought to us with the home stereo is that we can listen to something that was recorded at say 90 dB at 50 dB, and then we can use the loudness function to compensate for the DIFFERENCE between the phon curves for those levels. In the treble the DIFFERENCE between the curves is minimal, but in the bass the difference is large. Do you have access to the numbers that make up the FM diagram so that we could compute the differences and close this, once and for all? I am aware that the curves may include tolerances, but so should the difference numbers that comes out of this. I remember vaguely trying to get these numbers, but the best I found was someone having traced the diagrams. Sorry. Could you fix this? Designing a loudness compensation circuit based on this would be trivial, at least in the digital domain, and it's only drawback would be the difficulty in setting the original venue loudness. ....and the efficiency of the loudspeakers, power amp gain, room reverberation radius, etc. But of course, these could be measured, You are right in that the level of the original recording is the toughest one to estimate. There are other issues as well, like that the FM curves are measured with sinusoidal sounds. There are effects, like masking and such, that will make an exact compensation difficult. I recall that this was my reason to give up digging for the FM numbers the last time, they would not do what I wanted since I used complex sounds (not sinusoiuds). Per, E-73 at KTH and a big fan of mr Fant and pip-Johan. Yes, aren't they great? Svante, E-85 at KTH and a big fan of mr Fant and pip-Johan. |
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Stereo Loudness Control?
Per Stromgren wrote in message . ..
On 10 Feb 2004 03:48:55 -0800, (Svante) wrote: So, do you not understand or do you think I am wrong? I am aware that each of the phon curves are non-flat, but it does not make sense to compensate for the curves themselves, since we use them in everyday life. The unnatural thing that is brought to us with the home stereo is that we can listen to something that was recorded at say 90 dB at 50 dB, and then we can use the loudness function to compensate for the DIFFERENCE between the phon curves for those levels. In the treble the DIFFERENCE between the curves is minimal, but in the bass the difference is large. Do you have access to the numbers that make up the FM diagram so that we could compute the differences and close this, once and for all? I am aware that the curves may include tolerances, but so should the difference numbers that comes out of this. I remember vaguely trying to get these numbers, but the best I found was someone having traced the diagrams. Sorry. Could you fix this? Designing a loudness compensation circuit based on this would be trivial, at least in the digital domain, and it's only drawback would be the difficulty in setting the original venue loudness. ....and the efficiency of the loudspeakers, power amp gain, room reverberation radius, etc. But of course, these could be measured, You are right in that the level of the original recording is the toughest one to estimate. There are other issues as well, like that the FM curves are measured with sinusoidal sounds. There are effects, like masking and such, that will make an exact compensation difficult. I recall that this was my reason to give up digging for the FM numbers the last time, they would not do what I wanted since I used complex sounds (not sinusoiuds). Per, E-73 at KTH and a big fan of mr Fant and pip-Johan. Yes, aren't they great? Svante, E-85 at KTH and a big fan of mr Fant and pip-Johan. |
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Stereo Loudness Control?
"Svante" wrote in message m... "Karl Uppiano" wrote in message ... "Svante" wrote in message om... "Karl Uppiano" wrote in message . .. [snip my stuff] Good explanation, with one exception. The treble should NOT be turned up. It is commonly done with the loudness button, but there is no physiological excuse for doing so. Have a look at the Fletcher-Munson curves, eg at: http://www.webervst.com/fm.htm Now, the low frequencies are *compressed*, that is, moving 10 dB down may yield a perceived drop of 15-20 dB (or Phon to be absolutely correct). At mid and high frequencies a 10 dB drop will yield approximately a 10 dB perceived drop. The net result is that when the volume is turned down, the bass (only) appears to have dropped more than the mid and high. So, the treble should not be turned up, at least not for physiological reasons. Human hearing sensitivity isn't flat at any volume, but we do have a lower sensitivity threshold at the mid range than at the frequency extremes. The curves show a greater difference between mid-range and treble sensitivity at low volumes, They do? For example, look at: http://www.webervst.com/fm.htm Specifically look at 1kHz 0 phon and then go to 10 kHz 0 phon, 10 dB difference, right? Then 1kHz 30 phon and go to 10 kHz, 10 dB difference again. To my eye, all phon curves look nearly identical above 1 kHz up to 90 phon. So, IMO there is little compression in the treble, and little need for a treble boost as part of a loudness function. There isn't as much in the treble, but there is some, particularly if you look at the difference between the deepest trough at around 4 kHz and the area above 10 kHz. Admittedly, the difference in the bass is much more pronounced. although not as much greater as the difference between mid-range and bass. So some treble equalization is required. Loudness compensation as typically implemented (using only equalization) probably doesn't work very well because what is really needed is frequency-dependent dynamic range compression at lower volumes. That is an interesting thought, to keep the really weak sounds from getting below the hearing threshold. Hmm... Might be practical, but hardly hifidilistic, but so isn't the loudness button in the first place. :-) It depends on the execution. Turning down the volume below the original level could be considered non-hifidilistic (although that might not convince the downstairs neighbor), in which case, an active loudness compensation circuit might be better than nothing. |
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Stereo Loudness Control?
"Svante" wrote in message m... "Karl Uppiano" wrote in message ... "Svante" wrote in message om... "Karl Uppiano" wrote in message . .. [snip my stuff] Good explanation, with one exception. The treble should NOT be turned up. It is commonly done with the loudness button, but there is no physiological excuse for doing so. Have a look at the Fletcher-Munson curves, eg at: http://www.webervst.com/fm.htm Now, the low frequencies are *compressed*, that is, moving 10 dB down may yield a perceived drop of 15-20 dB (or Phon to be absolutely correct). At mid and high frequencies a 10 dB drop will yield approximately a 10 dB perceived drop. The net result is that when the volume is turned down, the bass (only) appears to have dropped more than the mid and high. So, the treble should not be turned up, at least not for physiological reasons. Human hearing sensitivity isn't flat at any volume, but we do have a lower sensitivity threshold at the mid range than at the frequency extremes. The curves show a greater difference between mid-range and treble sensitivity at low volumes, They do? For example, look at: http://www.webervst.com/fm.htm Specifically look at 1kHz 0 phon and then go to 10 kHz 0 phon, 10 dB difference, right? Then 1kHz 30 phon and go to 10 kHz, 10 dB difference again. To my eye, all phon curves look nearly identical above 1 kHz up to 90 phon. So, IMO there is little compression in the treble, and little need for a treble boost as part of a loudness function. There isn't as much in the treble, but there is some, particularly if you look at the difference between the deepest trough at around 4 kHz and the area above 10 kHz. Admittedly, the difference in the bass is much more pronounced. although not as much greater as the difference between mid-range and bass. So some treble equalization is required. Loudness compensation as typically implemented (using only equalization) probably doesn't work very well because what is really needed is frequency-dependent dynamic range compression at lower volumes. That is an interesting thought, to keep the really weak sounds from getting below the hearing threshold. Hmm... Might be practical, but hardly hifidilistic, but so isn't the loudness button in the first place. :-) It depends on the execution. Turning down the volume below the original level could be considered non-hifidilistic (although that might not convince the downstairs neighbor), in which case, an active loudness compensation circuit might be better than nothing. |
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Stereo Loudness Control?
"Svante" wrote in message m... "Karl Uppiano" wrote in message ... "Svante" wrote in message om... "Karl Uppiano" wrote in message . .. [snip my stuff] Good explanation, with one exception. The treble should NOT be turned up. It is commonly done with the loudness button, but there is no physiological excuse for doing so. Have a look at the Fletcher-Munson curves, eg at: http://www.webervst.com/fm.htm Now, the low frequencies are *compressed*, that is, moving 10 dB down may yield a perceived drop of 15-20 dB (or Phon to be absolutely correct). At mid and high frequencies a 10 dB drop will yield approximately a 10 dB perceived drop. The net result is that when the volume is turned down, the bass (only) appears to have dropped more than the mid and high. So, the treble should not be turned up, at least not for physiological reasons. Human hearing sensitivity isn't flat at any volume, but we do have a lower sensitivity threshold at the mid range than at the frequency extremes. The curves show a greater difference between mid-range and treble sensitivity at low volumes, They do? For example, look at: http://www.webervst.com/fm.htm Specifically look at 1kHz 0 phon and then go to 10 kHz 0 phon, 10 dB difference, right? Then 1kHz 30 phon and go to 10 kHz, 10 dB difference again. To my eye, all phon curves look nearly identical above 1 kHz up to 90 phon. So, IMO there is little compression in the treble, and little need for a treble boost as part of a loudness function. There isn't as much in the treble, but there is some, particularly if you look at the difference between the deepest trough at around 4 kHz and the area above 10 kHz. Admittedly, the difference in the bass is much more pronounced. although not as much greater as the difference between mid-range and bass. So some treble equalization is required. Loudness compensation as typically implemented (using only equalization) probably doesn't work very well because what is really needed is frequency-dependent dynamic range compression at lower volumes. That is an interesting thought, to keep the really weak sounds from getting below the hearing threshold. Hmm... Might be practical, but hardly hifidilistic, but so isn't the loudness button in the first place. :-) It depends on the execution. Turning down the volume below the original level could be considered non-hifidilistic (although that might not convince the downstairs neighbor), in which case, an active loudness compensation circuit might be better than nothing. |
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Stereo Loudness Control?
"Svante" wrote in message m... "Karl Uppiano" wrote in message ... "Svante" wrote in message om... "Karl Uppiano" wrote in message . .. [snip my stuff] Good explanation, with one exception. The treble should NOT be turned up. It is commonly done with the loudness button, but there is no physiological excuse for doing so. Have a look at the Fletcher-Munson curves, eg at: http://www.webervst.com/fm.htm Now, the low frequencies are *compressed*, that is, moving 10 dB down may yield a perceived drop of 15-20 dB (or Phon to be absolutely correct). At mid and high frequencies a 10 dB drop will yield approximately a 10 dB perceived drop. The net result is that when the volume is turned down, the bass (only) appears to have dropped more than the mid and high. So, the treble should not be turned up, at least not for physiological reasons. Human hearing sensitivity isn't flat at any volume, but we do have a lower sensitivity threshold at the mid range than at the frequency extremes. The curves show a greater difference between mid-range and treble sensitivity at low volumes, They do? For example, look at: http://www.webervst.com/fm.htm Specifically look at 1kHz 0 phon and then go to 10 kHz 0 phon, 10 dB difference, right? Then 1kHz 30 phon and go to 10 kHz, 10 dB difference again. To my eye, all phon curves look nearly identical above 1 kHz up to 90 phon. So, IMO there is little compression in the treble, and little need for a treble boost as part of a loudness function. There isn't as much in the treble, but there is some, particularly if you look at the difference between the deepest trough at around 4 kHz and the area above 10 kHz. Admittedly, the difference in the bass is much more pronounced. although not as much greater as the difference between mid-range and bass. So some treble equalization is required. Loudness compensation as typically implemented (using only equalization) probably doesn't work very well because what is really needed is frequency-dependent dynamic range compression at lower volumes. That is an interesting thought, to keep the really weak sounds from getting below the hearing threshold. Hmm... Might be practical, but hardly hifidilistic, but so isn't the loudness button in the first place. :-) It depends on the execution. Turning down the volume below the original level could be considered non-hifidilistic (although that might not convince the downstairs neighbor), in which case, an active loudness compensation circuit might be better than nothing. |
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