Toward a Theory To Increase Mutual Understanding and Predictability

[RogerD]

I don't see how having all components plugged into a single power distributor isn't single point grounding?

Also, pathway to ground doesn't matter at all, it's on the first couple pages of the pdf you linked to. What is important is reducing resistance between component grounds.

And on shielding, measurable high frequency roll off isn't the issue, but dull sound still is. I'm not totally sure why, but I'm certainly not alone in noticing the issue.

Not true ,bonding equipment together increases the pathway to ground. The larger the pathway the lower the resistance,but the size of the pathway is the most important. Mercury and living stereo recording have very low noise floors even using standard audio cables. Why because the pathway to ground by bonding schemes reduced noise floors,they engineered it that way.

The bonding scheme is a separate pathway for noise back to ground.

 

[amirm]

2. I know you're an intelligent gent so I wanna be careful as not to offend or pretend I am, but I along with some intelligent gents like yourself have held the belief that information below the noise floor threshold cannot be heard. And I hate to use this because it can have the appearance of circular logic, but it would seem this supposed inability to hear anything below the noise floor belief might be somewhat substantiated at least to some degree by the Wiki graph caption stating "Signals below the noise floor cannot be measured." and I would suggest substituting measured for heard.

This has nothing to do with intelligence but rather, knowledge and experience. You can gather the same easily. Ethan has a nice listening test for this: http://ethanwiner.com/audibility.html#part2

Here are the two links:

Tones -10 db below noise: http://ethanwiner.com/tones-10.wav
Tones -20 db below noise: http://ethanwiner.com/tones-20.wav

Both are pretty audible to me. He also has samples for speech and music.

Net, net what Morricab told you is true. We can and do hear below noise floor assuming both are audible to start.

The topic is actually more complex in that directional noise is more audible than broad noise. In that regard, noise coming out of your speakers is more audible than noise that surrounds you in the room.

 

[DaveC]

Not true ,bonding equipment together increases the pathway to ground. The larger the pathway the lower the resistance,but the size of the pathway is the most important. Mercury and living stereo recording have very low noise floors even using standard audio cables. Why because the pathway to ground by bonding schemes reduced noise floors,they engineered it that way.

The bonding scheme is a separate pathway for noise back to ground.

Maybe its just semantics, but page 4 of the Jim Brown paper you linked to would disagree with your assertions.

 

[RogerD]

Maybe its just semantics, but page 4 of the Jim Brown paper you linked to would disagree with your assertions.

Very simple,rack mount your gear and strap the rack to ground. That creates a large pathway to ground which makes all noise common node. It is very common,but not in the high end except for these half assed attempts by these new grounding devices.

I do this and it works for me....to each his own.

 

[microstrip]

(...) The most frequent comment of any audiophile entering the room is of its silence and the fact their voice sounds so natural.

This is a very good signal - unfortunately in most treated rooms voice sounds muffled. They sound silent, but we feel we have to talk louder than usual.

 

[microstrip]

Not true ,bonding equipment together increases the pathway to ground. The larger the pathway the lower the resistance,but the size of the pathway is the most important. Mercury and living stereo recording have very low noise floors even using standard audio cables. Why because the pathway to ground by bonding schemes reduced noise floors,they engineered it that way.

The bonding scheme is a separate pathway for noise back to ground.

You can not compare the EMI conditions in the 60'sup to the 90's with current days. Ralph Morrison openly refers to it in more recent editions of his classic book Grounding and Shielding Techniques in Instrumentation. In these aspects we are amateurish debating complicated subjects.

See this interesting page on grounding subjects: https://interferencetechnology.com/designing-electronic-systems-for-emc-grounding-for-the-control-of-emi-3/.

 

[RogerD]

You can not compare the EMI conditions in the 60'sup to the 90's with current days. Ralph Morrison openly refers to it in more recent editions of his classic book Grounding and Shielding Techniques in Instrumentation. In these aspects we are amateurish debating complicated subjects.

See this interesting page on grounding subjects: https://interferencetechnology.com/designing-electronic-systems-for-emc-grounding-for-the-control-of-emi-3/.

I laugh....does anybody really think that a audiophile system is better than a engineered recording studio grounding system? When even a larger conductor in a duplex design yields a sonic improvement? The problem is the majority sticks with the status quo, I don't and What I have done has reaped large sonic benefits. I'm done with this subject.

 

[Al M.]

Nice Al... I could definitely go Stockhausen as well.
My desert island classical list could be brought to you by composers starting with the letters S or B (in mini homage to Sesame Street) including Scarlatti, Shostakovich, Stravinsky, Schubert, Schumann, Sibelius, Stockhausen, Bach, Beethoven, Brahms, Bartok and Barber... who wrote 2 of the great concertos of all time (his piano and his cello concerto). These are all masters for sure. I'm sure I've missed more than I've covered tho and would be a tattoo too big given how little space I actually have left for any more ink.

Mine would go from the letters A to Z, so I would need some space on the island. If there wasn't, I' d settle for yours but would bring some Handel, Schnittke, Berio and Prokofiev as well.

Thank you, Gentlemen, for some inspiration.

This afternoon I was listening to
Schubert, Winterreise (song cycle for baritone and piano)
Schnittke, string quartet # 4 (1989)

The Schnittke was played in a terrific performance by the Kaprilova Quartet, with four female players. It was recorded live during the Prague Spring 2002. When I bought this CD in Prague in 2010, it inspired me to look up the Prague Spring Festival. As a consequence I visited the festival with my father in 2012, and we saw terrific performances by, among others, the BBC Symphony, Czech Philharmonic and the Polish National Orchestra. Prague also happens to be one of my favorite cities in the world.

The main concert hall is also incredibly beautiful, with great sound:

https://commons.wikimedia.org/wiki/...nicipal_House_(Obecni_Dum),_Prague_-_8943.jpg

 

[stehno]

This has nothing to do with intelligence but rather, knowledge and experience. You can gather the same easily. Ethan has a nice listening test for this: http://ethanwiner.com/audibility.html#part2

Here are the two links:

Tones -10 db below noise: http://ethanwiner.com/tones-10.wav
Tones -20 db below noise: http://ethanwiner.com/tones-20.wav

Both are pretty audible to me. He also has samples for speech and music.

Net, net what Morricab told you is true. We can and do hear below noise floor assuming both are audible to start.

The topic is actually more complex in that directional noise is more audible than broad noise. In that regard, noise coming out of your speakers is more audible than noise that surrounds you in the room.

Amir, I have my own opinion but in your opinion, which would you consider to be the bigger hack, Ethan Winer or you?

 

[microstrip]

I laugh....does anybody really think that a audiophile system is better than a engineered recording studio grounding system? When even a larger conductor in a duplex design yields a sonic improvement? The problem is the majority sticks with the status quo, I don't and What I have done has reaped large sonic benefits. I'm done with this subject.

No, but a current audiophile system has electrical problems that a recording studio in the 50's did not have. Any way, please go on laughing ...

 

[RogerD]

No, but a current audiophile system has electrical problems that a recording studio in the 50's did not have. Any way, please go on laughing ...

I don't laugh at real sonic bliss,especially when I accomplish it by intellect.

 

[morricab]

Morricab, I'm way outta my league here as with most things, but with all due respect:

1. I always thought tape hiss was not a noise floor threshold but rather an audible noise generated by the friction induced by the physical tape lightly brushing against the recording heads???? If there's any truth to that, then I can't imagine tape hiss in and of itself being a noise floor threshold but rather just another audible noise in a certain frequency range for which indeed we could and should hear other info above and below and maybe even right smack dab in the middle of it.

2. I know you're an intelligent gent so I wanna be careful as not to offend or pretend I am, but I along with some intelligent gents like yourself have held the belief that information below the noise floor threshold cannot be heard. And I hate to use this because it can have the appearance of circular logic, but it would seem this supposed inability to hear anything below the noise floor belief might be somewhat substantiated at least to some degree by the Wiki graph caption stating "Signals below the noise floor cannot be measured." and I would suggest substituting measured for heard.

3. As you offer a potential reason for Curl's serious but unknown flaw, please bear in mind Curl made it abundantly clear that he was speaking not only of all his own designs but also ALL of his colleagues' designs including Mark Levinson who was present yet made no attempt to refute Curl's statement. IMO, and being front and center in that discussion, I interpreted Curl's admission of serious but unknown flaws as being a perplexing universal matter for every designer he communicated with and all who may address negative feedback in various and differing ways. As I recall everybody engaged in that discussion seemed to have much the same interpretation / understanding I had.

1. A noise floor can only be as low as the loudest source of noise. Therefore, if tape hiss is the loudest noise source (i.e. assuming that the noise floor of your system is quieter than this...which is likely) then for that recording at least, the noise floor is defined by that tape hiss. Now, let's say your recording is totally silent, then the noise floor is defined by the lowest noise generated either by your system or by external sources (traffic outside for example). Of course noise has some masking effects on signal but our brains can sort a lot of that out...see below.

2. In science we are often times extracting tiny signals that are buried in the noise. There are many techniques for this like averaging, lock-in amplifiers, filtering etc. It is true that you cannot measure a signal below the noise floor as is. However, signal can be extracted out of the noise and our ear/brain, which is a superb pattern recognition system can in fact hear things below a true noise floor. You would agree with me that there can be signals below the noise floor? Correlation with signals above the noise floor allows us to hear things that are correlated and discriminate against noise. You agree, that you can hear soft sounds, like a brush on a snare, that are softer than tape hiss on older recordings. Measured and heard are not equivalent in a lot of circumstances. The real problem comes, as I said before, when the noise floor itself is correlated with the signal...as it is with feedback electronics.

3. I read it as Curl kind of acknowledging that he has designed how he thinks is right but that the sound does not live up to his expectations. A huge majority of designers are "by the book" designers using engineering best practice that include negative feedback. The sound of most electronics is not realistic in any reasonable way, IMO. I think that this was a wrong turn (along with push/pull) in electronics design about 80 years ago. Of course I am making my own interpretation so you can take it merely as IMO because I don't know what Curl really meant but neither does anyone else.

 

[morricab]

Amir, I have my own opinion but in your opinion, which would you consider to be the bigger hack, Ethan Winer or you?

I don't think that is an appropriate comment. Amir simply provided you with a way to look into this topic and you make a personal attack?

 

[Whatmore]

Amir, I have my own opinion but in your opinion, which would you consider to be the bigger hack, Ethan Winer or you?

I don't think that is an appropriate comment. Amir simply provided you with a way to look into this topic and you make a personal attack?

ironic really, given what this thread is about

 

[FrantzM]

Amir, I have my own opinion but in your opinion, which would you consider to be the bigger hack, Ethan Winer or you?

I don't think that is an appropriate comment. Amir simply provided you with a way to look into this topic and you make a personal attack?

I am with morricab.
An unfortunate trend these days

 

[microstrip]

(...) The real problem comes, as I said before, when the noise floor itself is correlated with the signal...as it is with feedback electronics. (...)

Can you develop this interesting sentence?

 

[stehno]

1. A noise floor can only be as low as the loudest source of noise. Therefore, if tape hiss is the loudest noise source (i.e. assuming that the noise floor of your system is quieter than this...which is likely) then for that recording at least, the noise floor is defined by that tape hiss. Now, let's say your recording is totally silent, then the noise floor is defined by the lowest noise generated either by your system or by external sources (traffic outside for example). Of course noise has some masking effects on signal but our brains can sort a lot of that out...see below.

2. In science we are often times extracting tiny signals that are buried in the noise. There are many techniques for this like averaging, lock-in amplifiers, filtering etc. It is true that you cannot measure a signal below the noise floor as is. However, signal can be extracted out of the noise and our ear/brain, which is a superb pattern recognition system can in fact hear things below a true noise floor. You would agree with me that there can be signals below the noise floor? Correlation with signals above the noise floor allows us to hear things that are correlated and discriminate against noise. You agree, that you can hear soft sounds, like a brush on a snare, that are softer than tape hiss on older recordings. Measured and heard are not equivalent in a lot of circumstances. The real problem comes, as I said before, when the noise floor itself is correlated with the signal...as it is with feedback electronics.

3. I read it as Curl kind of acknowledging that he has designed how he thinks is right but that the sound does not live up to his expectations. A huge majority of designers are "by the book" designers using engineering best practice that include negative feedback. The sound of most electronics is not realistic in any reasonable way, IMO. I think that this was a wrong turn (along with push/pull) in electronics design about 80 years ago. Of course I am making my own interpretation so you can take it merely as IMO because I don't know what Curl really meant but neither does anyone else.

Morricab,

1. It seems we have different understandings about noise floors. I don't believe for one second the noise floor is determined by the loudest noise source, nor have I ever heard of this definition before. Especially since there are audible noises scattered throughout the frequency spectrum, some which may be intentional, some that come and go, and others that remain constant. Moreover, I'm convinced that our sensitive electronics are or should be indiscriminate between audible noise and music, as it's all just info being processed - If that's even a point worth mentioning here. Regardless, some claim (and I agree) that the worst distortions (noise) that most greatly harm our playback systems are those distortions / noises which cannot be heard and according to some cannot be measured, yet these same inaudible distortions (noise) are perhaps the greatest contributor to determining the noise floor level.

2. In light of my response above (#1) and the claim that a signal cannot be measured below the noise floor. Supposedly tape hiss is somewhere in the range of 500Hz - 2500Hz. Hence, if I'm correctly understanding your claim that the loudest noise determines the noise floor level, then there's much music info in the lower regions that cannot be measured if tape hiss is present. That's just odd to me.

With regard to noise floor topic in general, I'm just gonna stick with Wikipedia's definition, which in my endeavors seems very consistent with the simple understanding I've developed over years from others I consider to be in-the-know about this subject.

3. Regarding Curl's admission. You were not present for any part of that lengthy discussion spanning several months. Hence you have no awareness of the context of the topic of discussion (the OP), nor do you have any awareness of the context for the given time/day for which Curl made this admission. As such I'm quite confident you took and continue to take Curl's admission completely out of context. I already tried once to correct you about this but you continue to respond without seemingly taking this in the limited context I tried to convey.

 

[DaveC]

ironic really, given what this thread is about

Extremely predictable though...

 

[Ron Resnick]

Gentlemen, back to your corners!

Perhaps consider a new, dedicated noise floor thread, and let's allow this thread to return to its title topic?

 

[morricab]

Morricab,

1. It seems we have different understandings about noise floors. I don't believe for one second the noise floor is determined by the loudest noise source, nor have I ever heard of this definition before. Especially since there are audible noises scattered throughout the frequency spectrum, some which may be intentional, some that come and go, and others that remain constant. Moreover, I'm convinced that our sensitive electronics are or should be indiscriminate between audible noise and music, as it's all just info being processed - If that's even a point worth mentioning here. Regardless, some claim (and I agree) that the worst distortions (noise) that most greatly harm our playback systems are those distortions / noises which cannot be heard and according to some cannot be measured, yet these same inaudible distortions (noise) are perhaps the greatest contributor to determining the noise floor level.

2. In light of my response above (#1) and the claim that a signal cannot be measured below the noise floor. Supposedly tape hiss is somewhere in the range of 500Hz - 2500Hz. Hence, if I'm correctly understanding your claim that the loudest noise determines the noise floor level, then there's much music info in the lower regions that cannot be measured if tape hiss is present. That's just odd to me.

With regard to noise floor topic in general, I'm just gonna stick with Wikipedia's definition, which in my endeavors seems very consistent with the simple understanding I've developed over years from others I consider to be in-the-know about this subject.

3. Regarding Curl's admission. You were not present for any part of that lengthy discussion spanning several months. Hence you have no awareness of the context of the topic of discussion (the OP), nor do you have any awareness of the context for the given time/day for which Curl made this admission. As such I'm quite confident you took and continue to take Curl's admission completely out of context. I already tried once to correct you about this but you continue to respond without seemingly taking this in the limited context I tried to convey.

Try this out (see the link). As you can see, the highest noise in your system will determine approximately the noise floor. Even if you have 4 sources of noise at 30db each the combined noise will be 36db. If only one is at 30db and the rest are 10db or more lower then you have only about 31db...effectively the same loudness as the loudest noise.

http://www.snapfour.com/combinednoise_calculations.aspx

of course this is probably assuming white or pink noise that are more broadband.

From Noise (wikipedia):
"From a physics standpoint, noise is indistinguishable from sound, as both are vibrations through a medium, such as air or water. The difference arises when the brain receives and perceives a sound." Perception is the key.

"In audio engineering, noise can refer to the unwanted residual electronic noise signal that gives rise to acoustic noise heard as a hiss"

From Noise Floor (wikipedia)
"In signal theory, the noise floor is the measure of the signal created from the sum of all the noise sources and unwanted signals within a measurement system, where noise is defined as any signal other than the one being monitored."

However, as I demonstrated with calculator up there, the addition is not linear so the loudest noise source has by far the biggest impact on the total noise level and is essentially the noise floor.

"If the dominant noise is generated within the measuring equipment (for example by a receiver with a poor noise figure) then this is an example of an instrumentation noise floor, as opposed to a physical noise floor."


"and the claim that a signal cannot be measured below the noise floor" I have searched Wikipedia and I do not find this claim anywhere.

In fact I find articles like this:
http://ieeexplore.ieee.org/document/882477/?reload=true


Believe what you want, the facts don't change based on your beliefs:

"Tape hiss is the high frequency noise present on analogue magnetic tape recordings caused by the size of the magnetic particles used to make the tape. Effectively it is the noise floor of the recording medium. It can be reduced by the use of finer magnetic particles or by increasing the amount of tape used per second to record a signal. It can also be reduced by increasing the track width of the recording. A 3 dB reduction in hiss occurs for every doubling of the track width." It doesn't matter so much about lower frequencies since your hearing sensitivity is lower. Tape hiss is right in the prime hearing region. Nevertheless, you can still hear sounds softer than that...even in that frequency range.

Well, I really don't care about Curl's admission to be honest...I never liked the sound of any of his gear designs anyway.