The null tester

[Guest Eggcup The Daft]

7 hours ago, davewantsmoore said:

Pets should have 'real' names.... people names.   You don't call your dog Spot, or Bluey .... You call them Craig, or Simon.    

 

Our other cats are named Alan, and Freya.

 

https://www.youtube.com/watch?v=XgvR3y5JCXg

 

Most of our family's pets had or have "real names". One exception was my sister's pure white albino rabbit, who she insisted on calling - Spot.

[Guest Eggcup The Daft]

7 hours ago, MLXXX said:

I often read on this forum references to a highly resolving system and that appears to be purely a subjective evaluation. 

The subjective description of a highly resolving system is of course mainly defined in the negative.

 

As in "you can't hear the difference between an ordinary power lead and this cryogenically processed quantum-enabled nano enhanced cable is because your system is not sufficiently highly resolving".

[LHC]

Well, well, well. Fight Night is coming - Ethan Winer vs Paul McGowan. In short Paul (in one of his video) questioned whether Ethan's null test captured all factors that determine the sound quality of cables, and thereby saying the null test video was incomplete. Obviously Ethan is not taking this lightly and has publicly challenge Paul to a debate over the issue of completeness. Now let see how Paul of PS Audio would respond to this, if at all. Don't forget Paul has access to some highly resolving systems in his company, so one can assume his opinion are based on his experience with them. 

 

 

 

[MLXXX]

Shortly after 4m 54sec into the video, Paul MGowan, in explaining there can be an audible difference in practice, even with a  null in a test, states, "Well, no, if it's not electrical in the same way that you're running the test."

 

Is this a reference to the impedance used for the null test? Or the level of radio frequency interference in the test environment? Hard to know.

 

The onus would appear to be on Paul McGowan to come up with a practical example illustrating his point.   This example would need to involve a difference that was demonstrably audible.  And I suggest it would need to be something that could reasonably be expected to arise in practice in an audiophile's living room. So we would exclude setting up a test audiophile rig at the CERN Large Hadron Collider, at an airport radar installation, or at any other place with unusual, hostile, conditions.

Edited January 4, 2019 by MLXXX

[Addicted to music]

bring it on.....

[MLXXX]

Unfortunately I don't think there would be a clear "winner".

 

Paul McGowan's sincere tone and use of audiophile buzz words could easily prevail over Ethan Winer's clearly expressed logic and references to practical demonstrations.

 

Those with an electronics background might tend to side with Ethan, and those steeped in audiophile lore would likely side with Paul.

[LHC]

5 minutes ago, MLXXX said:

Unfortunately I don't think there would be a clear "winner".

 

Paul McGowan's sincere tone and use of audiophile buzz words could easily prevail over Ethan Winer's clearly expressed logic and references to practical demonstrations.

 

Those with an electronics background might tend to side with Ethan, and those steeped in audiophile lore would likely side with Paul.

I can't say this is an accurate representation of the situation here; it is not a dichotomy between 'audiophile' and 'electronics', nor 'buzz words' and 'logic'. But I do agree that a clear winner may not emerge from any real debate, if it ever happens. Probably more worthwhile would be a demonstration, as you have suggested earlier, and people can make up their mind. 

[Addicted to music]

One thing for sure, Ethan has to maintain his composure, chillout and have a bit of fun if he wants people to side with him.   It looks like he’s not taking it lightly,  even though he knows he’s going to get a response as he did from Paul.

 

[MLXXX]

43 minutes ago, Addicted to music said:

One thing for sure, Ethan has to maintain his composure, chillout and have a bit of fun if he wants people to side with him.

I agree. Towards the end of the video demonstrating the null testing device he did not appear to me to be projecting calmness and assuredness.  (He may not have been in good physical health.  )

 

On the other hand, his sparring partner is brim full of suaveness and sincerity, together with a laid back style.

 

All Paul McGowan would need would be a vague argument, well presented.

[MLXXX]

1 hour ago, LHC said:

I can't say this is an accurate representation of the situation here; it is not a dichotomy between 'audiophile' and 'electronics', nor 'buzz words' and 'logic'.

In my view it is.  Two audio cables measure the same to the point of creating a very deep null when used to pass an audio signal and its inverse. One party contends that the two cables can nevertheless sound different. Applying basic electronics theory, that is an extraordinary claim that prima facie demands extraordinary proof.

 

However I anticipate that the "proof" supplied would consist of the putting together of a selection of audiophile buzzwords, supported by the reciting of anecdotes of subjective impressions.  And there could possibly be mention of exceptional situations , such as subjecting shielded cables (that differ in the effectiveness of the shielding) to extraordinarily high levels of electromagnetic interference.

 

That's the level of debate I've come to expect when audible differences between signal cables are being discussed in the audiophile community.

[Addicted to music]

5 hours ago, MLXXX said:

I agree. Towards the end of the video demonstrating the null testing device he did not appear to me to be projecting calmness and assuredness.  (He may not have been in good physical health.  )

 

On the other hand, his sparring partner is brim full of suaveness and sincerity, together with a laid back style.

 

All Paul McGowan would need would be a vague argument, well presented.

It’s possible why he’s says he’s been kicked off and banned from many forums as he says in many of his presentations.   

Either way Paul has been a salesman, and is very good at doing so.  

 

 

4 hours ago, MLXXX said:

In my view it is.  Two audio cables measure the same to the point of creating a very deep null when used to pass an audio signal and its inverse. One party contends that the two cables can nevertheless sound different. Applying basic electronics theory, that is an extraordinary claim that prima facie demands extraordinary proof.

 

However I anticipate that the "proof" supplied would consist of the putting together of a selection of audiophile buzzwords, supported by the reciting of anecdotes of subjective impressions.  And there could possibly be mention of exceptional situations , such as subjecting shielded cables (that differ in the effectiveness of the shielding) to extraordinarily high levels of electromagnetic interference.

 

That's the level of debate I've come to expect when audible differences between signal cables are being discussed in the audiophile community.

A DBT would be more convincing for Paul.  

[LHC]

34 minutes ago, Addicted to music said:

Either way Paul has been a salesman, and is very good at doing so.

So is Ethan Winer, he sells room treatments. 

 

In any case one shouldn't simply trust someone, and buy their products, just because their pitch sounds appealing, either in 'electronics' or 'audiophile' buzz words. One should do their own research into the matter, and decides for oneself what works and makes the most sense. 

[Addicted to music]

38 minutes ago, LHC said:

So is Ethan Winer, he sells room treatments. 

 

In any case one shouldn't simply trust someone, and buy their products, just because their pitch sounds appealing, either in 'electronics' or 'audiophile' buzz words. One should do their own research into the matter, and decides for oneself what works and makes the most sense. 

This isn’t about room treatment....  

 

and yes, one should do there research,  get a unbiased opinion that’s If there is any.

Edited January 4, 2019 by Addicted to music

[MLXXX]

On 05/01/2019 at 5:23 AM, Addicted to music said:

A DBT would be more convincing for Paul.  

Well for scientists in the room, if two signal cables give a null to a very small fraction of a decibel when compared actually carrying an audio signal, it certainly is not going to cut any ice to claim they sound different unless it can be demonstrated rigorously, i.e. with a DBT. However there would be no point in embarking on a double blind test in the same conditions that Winer used, as it would be bound to fail. 

 

So McGowan, if he chooses to participate in a debate would either need to avoid any attempt to use a DBT or he would need to alter the test conditions such that one cable did perform differently, e.g. by placing the cables next to an intense magnetic field at 60Hz, or at a radio frequency.  An intense 60Hz field could generate audible hum that was more pronounced in one cable than the other (because of differences in shielding effectiveness). It would disturb the null audibly and would be visible on an oscilloscope display.

 

An intense, amplitude modulated, magnetic field at say 150kHz could penetrate one cable more than the other and if the null testing device is very linear might not be audible in Winer's test apparatus, though it should show up on the oscilloscope display when set to an appropriate time base. By  substituting a preamplifier that responded in a non-linear way to 150kHz, the modulation might become audible. If you touch the signal pin of an RCA cable connected to a high gain preamplifier, you may well hear buzz, or the sound of one of more local AM radio stations. Long-wave broadcasting still exists in various parts of the world. See https://en.wikipedia.org/wiki/Longwave#List_of_stations_currently_operating 

 

You could try to replicate this type of interference in real life, by placing your audio gear into your car, driving to a high-powered long-wave transmission site,  setting up your hi-fi gear on a picnic rug, or large tarpaulin, and turning on your portable power generator.  However even with such close proximity to a radio transmitter, there is no guarantee there would be an audible effect. 

 

Then there could be interference that produced sporadic spikes at radio frequencies. These might be difficult to capture on an oscilloscope, but could be audible if a preamplifier was used that was non-linear.

 

Clutching at straws really, but it might be the sort of argument McGowan might need to resort to.  However given his many years of giving talks on audio, I'm sure he could make the presentation entertaining, and persuasive for many in the audience; even though such a presentation might not cut much ice with technically inclined folk, given how intense the electromagnetic fields would need to be.

 

Perhaps the most sensitive situation would be a length of cable connecting a turntable magnetic cartridge to a preamplifier. The performance can be very dependant on the capacitance of the length of the cable,  and tends to be susceptible to stray electromagnetic fields.

Edited January 5, 2019 by MLXXX

[frednork]

Can someone please explain to me what is wrong with the Townshend videos. ie what is flawed about what he showed/said?

[Zaphod Beeblebrox]

7 hours ago, frednork said:

Can someone please explain to me what is wrong with the Townshend videos. ie what is flawed about what he showed/said?

What Townshend video would that be?

[frednork]

@Zaphod Beeblebrox please see middle of the quoted post

 

On 18/11/2018 at 9:59 AM, acg said:

 

But I've known plenty of dogs called Bluey...you may be surprised, we humans are not always particularly inventive when naming cattle dogs.  Also plenty of blokes called Bluey as well.

 

So, back to the topic, being a practical kind of guy I always prefer to see things tested in the way that they are actually used i.e. tested in use if possible.  For example, I might be looking for a new plough and find one that is very heavy and uses large girths of steel with plenty of wall thickness, over-specified bearings etc. and think that it will last me my lifetime if I were to buy it.  Get it home and stick it behind the tractor and I'm busting welds and bending this heavy steel and although it met my original specifications when shopping for the plough in real life, when I used the thing, those spec's were not suitable for telling me if the damn thing would last my lifetime or not.  That's an extreme example, but testing in real-world situations is where things really matter and this null test machine does not meet that primary criteria for me because the cable is being tested in isolation from the audio system. 

 

Not that I am in any way disputing EW's null test results or his honesty, but I just think that if he were to test the wires/cables in the audio system the result would be more meaningful.  Right near the start of the video he says... 

 

Here is an audio engineer making a somewhat different claim that transmission lines effects are significant at audio frequencies, and he is doing a real time null test in an actual representative audio system with a cd player, amplifier and speakers...

 

 

 

 

 

 

 

 

EW also claims...

 

I am disputing this, because when these wires are used in the real world for their real purpose other things may become important such as shielding.

 

Anyway, I'm not presenting the Townshend videos above as gospel, but I do find them quite interesting nonetheless.

 

 

 

  

 

 

[MLXXX]

On 18/11/2018 at 8:59 AM, acg said:

 

...

 

Here is an audio engineer making a somewhat different claim that transmission lines effects are significant at audio frequencies, and he is doing a real time null test in an actual representative audio system with a cd player, amplifier and speakers...

 



  

 

9 hours ago, frednork said:

Can someone please explain to me what is wrong with the Townshend videos. ie what is flawed about what he showed/said?

I'll provide a response in relation to the first video (the one I've left in, in  my extract above from acg's post).

 

A questionable claim (or, at least,  implication) is that a glitch that can be seen in a small part of a 2kHz squarewave will be audible.  That claim would need to be supported, e.g. using a blind test.  (In real life, speakers do not have a perfect squarewave response at 2kHz; and nor do microphones.)

 

This is a very, very important point to stress. We are not dolphins or bats. 

 

 

 

Another questionable aspect of this particular video is that although a number of the cables can be seen in their entirety, and can be coiled up, the Townshend cable is always partly out of the frame. Why are we not given a clear view of the whole of a Townshend cable? Is it set up with a wide radius curve to assist transmission?  Or is particularly short?  Perhaps those questions are answered somewhere else.  It's something that struck me the first time I saw this video!

Edited January 6, 2019 by MLXXX

[davewantsmoore]

27 minutes ago, MLXXX said:

In real life, speakers do not have a perfect squarewave response at 2kHz

Good speakers have very respectable square wave response at 2khz.

eg. https://www.minidsp.com/images/appnotes/rephase/rephase-2-kHz-square-wave-corrected.png

 

... but yes, I agree that it's not necessary that a small blip (I haven't watched the video yet) is going to be audible.

 

[frednork]

1 hour ago, davewantsmoore said:

Good speakers have very respectable square wave response at 2khz.

eg. https://www.minidsp.com/images/appnotes/rephase/rephase-2-kHz-square-wave-corrected.png

 

... but yes, I agree that it's not necessary that a small blip (I haven't watched the video yet) is going to be audible.

 

the blip was not that big in video 1 but by the time you get to video 4 the differences "look" audible.

Edited January 6, 2019 by frednork
spelling grammar etc

[LHC]

On 05/01/2019 at 11:12 AM, MLXXX said:

Well for scientists in the room, if two signal cables give a null to a very small fraction of a decibel when compared actually carrying an audio signal, it certainly is not going to cut any ice to claim they sound different unless it can be demonstrated rigorously, i.e. with a DBT. However there would be no point in embarking on a double blind test in the same conditions that Winer used, as it would be bound to fail. 

Since you referred to 'scientists', I think there will be some who don't agree there are 'no point in embarking on a double blind test ... as it would be bound to fail'. If there are no peer reviewed scientific papers reporting such results, it would be of interests to some (in reality they may not get the funding to do such experiment though). Scientists are driven by curiosity; if two cables measured the same under null test, but sound different under DBT, that would be an intriguing mystery for the most curious of them. 

 

In his video, Paul was referring to how the use of said cables may end up sounding a bit different - it is about what one hears. In the comment section of Ethan's Youtube video, Ethan made this comment: "My Null Tester, the subject of this video, has nothing to do with waves in the air. All it attempts to do is prove that two wires pass audio frequency AC the same. And it does that very well." So the missing piece is to correlate the null tested audio signals to the sound waves in the air heard by listeners - i.e. a DBT, or more precisely a blind ABX. It is the only way to clear the air. If it turns out to sound the same under ABX, that would be a great day for Ethan and similar audio skeptics; if it sound different it would be a great day for the curious scientists. Win-win.

 

If you want to see an example of the difference between Ethan and a scientist, have a read of his exchange with a guy called Christopher Ward (who claims to be a scientist) in the comment section of the Null test Youtube video. Obviously they are looking at the same reality from different perspectives. (I am assuming Christopher is not just trolling)

 

Finally the Ethan's null test is good for 110dB I believe. Now there are some who claims they could hear below this, much further even. One such person is Bob Watts of Chord Electronics. In the following lecture he talks about this and how it influenced his DAC design (starting from around 20:30 mark). He also claimed he had blind tested others and confirm they could hear this too. The lecture in its entirety is really interesting and covers many audio (myth?) topics of interest; worthy of a separate discussion thread. But back to the DBT/ABX for Ethan and Paul, what this implies is the need to use test subjects who can hear at such low level, just like Bob Watts. 

 

 

 

 

[Ittaku]

11 minutes ago, LHC said:

Finally the Ethan's null test is good for 110dB I believe. Now there are some who claims they could hear below this, much further even. One such person is Bob Watts of Chord Electronics. In the following lecture he talks about this and how it influenced his DAC design (starting from around 20:30 mark). He also claimed he had blind tested others and confirm they could hear this too.

For what it's worth, in my comparison of about half a dozen high end DACs, the only measurable difference between them was an alleged dynamic range far far far beyond what humans could hear. Yet the difference between DACs that had a DNR of 125 dB versus 135 versus 145(!) were all noticeable to me. I don't claim to be able to hear sounds that quiet so I think the dynamic range is purely a surrogate marker of something else going on. The fact that there is a measurable difference between them means they're not identical, even if theoretically those differences should not be audible. A null tester for 110dB will not pick up these differences. It's my running theory that the absurd dynamic ranges are simply representative of something else the DACs do correctly - to me it would seem to be that such obscene dynamic range means that the audible dynamic range (say just 50dB for most music content) is simply represented more linearly. The relationship between all the frequencies and amplitudes is maintained as closely as possible as to what's recorded in digital (barring the losses at the analogue to digital conversion stage of course!) I also postulate that this is what analogue (vinyl) does well easily, so that even if it has much higher noise, much lower dynamic range, and so on, it maintains the relationship between critical waveform amplitudes and frequencies, at the expense of the measurable quantities that don't necessarily translate into musical realism.

[davewantsmoore]

1 hour ago, LHC said:

Finally the Ethan's null test is good for 110dB I believe. Now there are some who claims they could hear below this, much further even. One such person is Bob Watts of Chord Electronics. In the following lecture he talks about this and how it influenced his DAC design (starting from around 20:30 mark).

  These are different things.

 

He is saying he can hear changes in the DAC filter, which are very low in level (eg. 200dB)

 

This isn't the same things as saying he can hear sound which is at that low level, like the null tester does.

 

 

For example.  If you were to hear something 110dB lower than another sound.    Let's say it's at the threshold of hearing, about 20dBA.... this would mean the louder sound was 130dB (!!!).     Even ignoring the masking effect of quiet and loud sounds .... this is not happening in practise (people don't listen with 130dB peaks).

[davewantsmoore]

55 minutes ago, Ittaku said:

I don't claim to be able to hear sounds that quiet so I think the dynamic range is purely a surrogate marker of something else going on.

Yes.   You cannot hear sounds this quiet.

 

Many of these types of measurements (eg. the noise floor) do not do a good job of explaining what happens with real (complex) content.

[MLXXX]

2 hours ago, LHC said:

Since you referred to 'scientists', I think there will be some who don't agree there are 'no point in embarking on a double blind test ... as it would be bound to fail'. If there are no peer reviewed scientific papers reporting such results, it would be of interests to some (in reality they may not get the funding to do such experiment though). Scientists are driven by curiosity; if two cables measured the same under null test, but sound different under DBT, that would be an intriguing mystery for the most curious of them. 

I suggest it would likely  be an intriguing mystery for even the less curious of them!

 

Things that appear impossible or at least highly unusual tend to attract a lot of interest, much as the 2011 neutrino speed anomaly proved to be intriguing for many scientists and non-scientists. (In that case, as you may recall, the apparent speed difference was found to be attributable  to experimental error: https://en.wikipedia.org/wiki/Faster-than-light_neutrino_anomaly  )

 

2 hours ago, LHC said:

In the comment section of Ethan's Youtube video, Ethan made this comment: "My Null Tester, the subject of this video, has nothing to do with waves in the air. All it attempts to do is prove that two wires pass audio frequency AC the same. And it does that very well." So the missing piece is to correlate the null tested audio signals to the sound waves in the air heard by listeners - i.e. a DBT, or more precisely a blind ABX. It is the only way to clear the air. If it turns out to sound the same under ABX, that would be a great day for Ethan and similar audio skeptics; if it sound different it would be a great day for the curious scientists. Win-win.

What you have described in your last sentence above is not what I would call a "win-win". (It appears to me to be a "win-lose", or "lose-win", depending on the camp. )

 

I'm not sure there is really a missing piece, unless it is thought that human ears will be able to hear a difference that is more than 100dB below the peak music listening level in the listening room, as the music is playing. In other words, we would be looking to hearing a distortion at 100dB down when the intended signal is at 0dB. We are in effect not looking at hearing a whisper in a quiet room, but hearing a whisper of altered transfer of sound in a room full of very loud pop music.

 

My previous paragraph assumes that as the driving signal gets less, the absolute level of the difference signal would get less. In the limit, if the driving signal reaches zero, the only difference emerging from two wires would be thermal noise and EMI noise, no actual signal.  So if the null is 100dB with a driving signal at 0dB, the null for the signal could be expected to be at -200dB with a driving signal at -100dB. (Of course unless an extremely high driving voltage were used initially for the nominal 0dB, such that -100dB was still well above thermal noise, this result would be highly theoretical, and certainly not measurable.)

 

 

2 hours ago, LHC said:

If you want to see an example of the difference between Ethan and a scientist, have a read of his exchange with a guy called Christopher Ward (who claims to be a scientist) in the comment section of the Null test Youtube video. Obviously they are looking at the same reality from different perspectives. (I am assuming Christopher is not just trolling)

I couldn't find these comments. Can you supply an approximate date when the exchange occurred?

Edited January 6, 2019 by MLXXX