"mana and fraim effect" Stochastic resonance...?
Posted by: yannzola on 25 February 2004
Ok. First I must be honest.... I am a complete idiot. Please excuse me if this topic has been discussed previously, or if I'm totally off the mark.
With that firmly in mind: Here's an idea that recently plopped into my head: Some claim that the resonant ringing tones of our beloved un-damped aluminum cases / mana racks / fraim's are somehow involved in "improving" the quality of the sound we hear.
To me, this seemed ridiculous. Utterly counter intuitive. How would adding resonant hash do anything but muddy the clarity of the signal? Common sense... right? Wrong! Sometimes noise can actually clarify and reveal otherwise subthreshold information! At least in certain instances... the principle in action is known as "Stochastic Resonance". A theory which deals with the effects of noise in a variety of non linear phenomena. Including accoustics... specifically applied psychoacoustics and human perception.
Here's an interesting visual example of stochastic resonance in action. Notice that there is a "sweet" spot where introduced noise clarifies the image.
Now... the ringing of "tuned" glass and aluminum cases is not really "stochastic noise" (which is more analogous to white/pink noise). However new reseach has found that high frequency "vibrational resonance" may behave in similiar ways. These resonances are periodic, and therefore "tonic". Similiar (perhaps?) to the tones we hear from our resonating glass racks, cases, etc.
Phew.
Just a thought...
y.
Here's a good primer on psychacoustics
[This message was edited by yannzola on WEDNESDAY 25 February 2004 at 17:36.]
[This message was edited by yannzola on WEDNESDAY 25 February 2004 at 17:37.]
[This message was edited by yannzola on WEDNESDAY 25 February 2004 at 17:38.]
With that firmly in mind: Here's an idea that recently plopped into my head: Some claim that the resonant ringing tones of our beloved un-damped aluminum cases / mana racks / fraim's are somehow involved in "improving" the quality of the sound we hear.
To me, this seemed ridiculous. Utterly counter intuitive. How would adding resonant hash do anything but muddy the clarity of the signal? Common sense... right? Wrong! Sometimes noise can actually clarify and reveal otherwise subthreshold information! At least in certain instances... the principle in action is known as "Stochastic Resonance". A theory which deals with the effects of noise in a variety of non linear phenomena. Including accoustics... specifically applied psychoacoustics and human perception.
Here's an interesting visual example of stochastic resonance in action. Notice that there is a "sweet" spot where introduced noise clarifies the image.
Now... the ringing of "tuned" glass and aluminum cases is not really "stochastic noise" (which is more analogous to white/pink noise). However new reseach has found that high frequency "vibrational resonance" may behave in similiar ways. These resonances are periodic, and therefore "tonic". Similiar (perhaps?) to the tones we hear from our resonating glass racks, cases, etc.
Phew.
Just a thought...
y.
Here's a good primer on psychacoustics
[This message was edited by yannzola on WEDNESDAY 25 February 2004 at 17:36.]
[This message was edited by yannzola on WEDNESDAY 25 February 2004 at 17:37.]
[This message was edited by yannzola on WEDNESDAY 25 February 2004 at 17:38.]
This is very close to being totally beyond me, but just enough of it makes just enough sense that I will risk responding, gently...
1. I think elements of this are already accepted to some degree in the audio field. Certainly I remember JV mentioning that the early Naim CDs had a low level of pink noise added at the mastering stage, as this improved the quality of the final result.
2. Wolfram's assertion that a digitised analogue signal (ie, a digital signal) is less affected by noise than the same signal undigitised, is undeniably correct. However, that only means that the result has less noise in it in terms of a percentage of the whole. It doesn't mean that the digitised signal is actually a more accurate representation of the original, as (for one thing) it has been forced to conform to limitations which are not present in the analogue domain. With a screen showing 16-bit colour for example, a colour in the original image which falls between the two closest colours which the screen can represent will be force-mapped to one of those colours, thereby departing from the original. The digitised image will inevitably contain less information. This trap is one which we fall into when judging digital solutions by the criteria evolved for analogue -- trees are percieved everywhere in finely-etched detail, but no-one thinks to ask where the forest has gone.
3. The point about audio equipment cases and supports "ringing" is well made. However, I think a straw poll taken amongst those who have tried it would probably reveal that most users of Naim boxes tend to prefer the results when said boxes are used with the cases removed. Mostly this applies to preamps and active crossovers, since no mains voltage would be exposed with these items.
Furthermore, experience has shown that items prone to "ringing" (for want of a better term) are much more easily excited by a vibrating item with which they are in physical contact (such as a turntable or a SuperCap) than they are by airborne vibration (or music, as it is sometimes called
). Since the vibrational energy fed in to the combination by the supported item is the same whatever support is in use, an easily excited support will cause the item being supported to be subject to a reduced total amount of vibration, affording the supported item's components a more favourable environment in which to perform their functions. Having sid that, I've never heard a Fraim with its aluminium organ pipes tightly stuffed with polystyrene -- must try that at Bristol 2005 -- but I would have thought it should sound a lot worse.
Best;
Mark
1. I think elements of this are already accepted to some degree in the audio field. Certainly I remember JV mentioning that the early Naim CDs had a low level of pink noise added at the mastering stage, as this improved the quality of the final result.
2. Wolfram's assertion that a digitised analogue signal (ie, a digital signal) is less affected by noise than the same signal undigitised, is undeniably correct. However, that only means that the result has less noise in it in terms of a percentage of the whole. It doesn't mean that the digitised signal is actually a more accurate representation of the original, as (for one thing) it has been forced to conform to limitations which are not present in the analogue domain. With a screen showing 16-bit colour for example, a colour in the original image which falls between the two closest colours which the screen can represent will be force-mapped to one of those colours, thereby departing from the original. The digitised image will inevitably contain less information. This trap is one which we fall into when judging digital solutions by the criteria evolved for analogue -- trees are percieved everywhere in finely-etched detail, but no-one thinks to ask where the forest has gone.
3. The point about audio equipment cases and supports "ringing" is well made. However, I think a straw poll taken amongst those who have tried it would probably reveal that most users of Naim boxes tend to prefer the results when said boxes are used with the cases removed. Mostly this applies to preamps and active crossovers, since no mains voltage would be exposed with these items.
Furthermore, experience has shown that items prone to "ringing" (for want of a better term) are much more easily excited by a vibrating item with which they are in physical contact (such as a turntable or a SuperCap) than they are by airborne vibration (or music, as it is sometimes called
). Since the vibrational energy fed in to the combination by the supported item is the same whatever support is in use, an easily excited support will cause the item being supported to be subject to a reduced total amount of vibration, affording the supported item's components a more favourable environment in which to perform their functions. Having sid that, I've never heard a Fraim with its aluminium organ pipes tightly stuffed with polystyrene -- must try that at Bristol 2005 -- but I would have thought it should sound a lot worse.Best;
Mark