Cable Directionality - do you want proof

[MajorFubar]

If you dont know what I mean by the super duper capacitor thats had its dielectic properties improved by a treatment designed by nasa - big story - you have missed about 10 minutes of thewhole presentation. That demo is clear cut if you cant hear that - hifi is wasted on you (speaking pluraly not attacking you personally.

I didn't miss it, I just couldn't hear a difference, for which there are three possible reasons if we rule-out the limitations of the camera's microphone and the sound quality of YouTube videos. 1) The studio monitors I'm listening on are not good enough, 2) my ears aren't good enough (I'm loaded with a cold and everything in general atm sounds muffled), 3) There is no spoon.

I shall sell my HiFi forthwith.

 

[Covenanter]

How can you say that - the differences in the capacitor test is especially clear and easy to hear - I think your being awkward there in that comment.

The cable direction swop test is difficult as I have said 10 times but several people have heard it same as me

You ignore the possibility that you are imagining the difference! If you hear something and I don't why do you have to be right (especially when I have the entire scientific community on my side)?

There have been any number of things in hifi that people have believed in over the years that have eventually been shown to be baloney (the one we all remember is marker pens and CDs). My favourite recently is wooden blocks to hold your speaker cables off the floor. People hear differences with these too.

Chris

 

[ellisdj]

For clarity - chat about the demo is from 43mins ish - i.e. what they have apparently done costing $50000

I got the test wrong

The actual demo is 45.30 mins ish - this is with the Niagra fully

Then he takes one of the treated capacitors and swops it for an untreated capacitor -

That demo is 47mins approx.

Again I have opened both demos up in 2 tabs and gone from one to the other and there is clear difference to me

 

[ellisdj]

its also black when its black and white when its white - not grey.

this is no small difference - its either the playback system or the receptacles in this instance - that was meant as joke btw otherwise I am a hypocrit

 

[RobinKidderminster]

If nothing else, this thread has identified a number of forumites who consistently argue factual, realistic, scientific and experiential discussion and those who don't.

I would still like to understand the YouTube audio quality issue - can it REALLY be adequate to hear noticeable differences and indeed improvements?

The OP heads "proof". There will (IMO) never be proof in a marketting demonstration.

 

[ellisdj]

Robin - its not about the quality - its just about hearing a difference in this instance - that is all the matters for purposes of watching a you tube video in this instance - analysing nothing but is there an audible difference. Obviously cant tell how it actually sounds

first demo cable direction I think yes there is a difference but I admittd that could easy go 50/50 and lets face it who would be surprised

By the second demo re the capacitor - its much clearer I think

 

[Thompsonuxb]

Why would you have an A/C output on an amp?

Why do you keep starting technical debates about subjects that you haven't educated yourself in beforehand? I'm sorry to say this but sometimes I feel almost embarrassed for you when you make comments like that. All it does is shows a complete and utter lack of understanding of even the most basic principle of how an audio amplifier and speakers work.

I'm not going to waste time trying to explain why an amplifer outputs A/C rather than D/C because you'd probably just completely miss the point as usual but the infomation is readily available on the internet if you want to educate yourself (something that I would strongly advise doing before posting about subjects that you don't understand).

 

I waited a good part of the evening waiting for such a response....

Just bare with me a moment while I put on my internet kung fu fighting pants.....hmmm, they feel tight.

This being an area that's not had much cover on this site.

So Steve_1979, you're not familiar with the difference between modulated D/C (what you'll get from your amp and causes the speaker to move) and an A/C electrical signal? - Usually seen coming in off your mains supply.

It's easy to confuse the two but different they are.

The PCB's in your amps innards are fed D/C hence the use of capacitors.what's amplified and outputted is not A/C.

I'm actually going to sit and wait for you fake boffins to go read up on this and see what you come back with.

 

[stavvy]

please someone correct me if I'm wrong, but surely if all the usual things that spark debate over whether they make a difference or not (i.e. cables, mains conditioners, etc), then this should be observable by recording the sound waves, inverting the signal for one of the test conditions (e.g. record the sound with the cable going in one direction, then record the same sound with the cable in the other direction but inverse the signal). Then if the waves are superimposed, if the cable direction makes a difference to make an audible difference, then surely there will be some kind of signal remaining (i.e. the part that is lost by having the cable the wrong way). Equally if there is no difference, the superimposed signal will be completely flat.

I really know nothing when it comes to audio engineering though, and I feel like if the cable manufacturers could prove their products could make a difference in this way they would (or equally cable skeptics could disprove this). I fail to believe there is a not scientific way of proving the audible effects of cables.

 

[richardw42]

I'm just wondering why people are bothering to argue with someone who has the letters TSIKOE in their signature.

 

[andyjm]

please someone correct me if I'm wrong, but surely if all the usual things that spark debate over whether they make a difference or not (i.e. cables, mains conditioners, etc), then this should be observable by recording the sound waves, inverting the signal for one of the test conditions (e.g. record the sound with the cable going in one direction, then record the same sound with the cable in the other direction but inverse the signal). Then if the waves are superimposed, if the cable direction makes a difference to make an audible difference, then surely there will be some kind of signal remaining (i.e. the part that is lost by having the cable the wrong way). Equally if there is no difference, the superimposed signal will be completely flat.

I really know nothing when it comes to audio engineering though, and I feel like if the cable manufacturers could prove their products could make a difference in this way they would (or equally cable skeptics could disprove this). I fail to believe there is a not scientific way of proving the audible effects of cables.

There is a free software app that does exactly as you describe. It records a 'before' track, then an 'after the change' track. It does some clever time and level alignment, and then saves a difference file. If the change has made no difference, then the difference file is silent. The 'change' can be whatever you like. Mains cable, speaker cable, USB cable, mains conditioner, whatever. It can conclusively prove whether a particular change has made an audible difference - or not.

The software is 'Audiodiffmaker' and can be found with google.

Given that there is a simple and repeatable way of demonstrating the effect of cables etc, it makes you wonder why firms who sell these products don't use 'Audiodiffmaker' to demonstrate the change that their product makes......

 

[MajorFubar]

I'm just wondering why people are bothering to argue with someone who has the letters TSIKOE in their signature.

I have this dream where I'm able to make gullible people realise they're being led up the garden path by merchants who expertly and cleverly tread the fine line between making dubious subjective claims that cannot be scientifically proven vs. blatently breaching the Trades Descriptions Act.

 

[scene]

The PCB's in your amps innards are fed D/C hence the use of capacitors.what's amplified and outputted is not A/C.

I'm actually going to sit and wait for you fake boffins to go read up on this and see what you come back with.

Now you're just trying to wangle out of your earlier comment where you said, obviously wrongly, that speakers were fed with DC. The closest truth is, by my primative understanding which I'm happy to let someone else correct, pure AC is a time varying electrical signal which periodically reverses it's polarity, crossing zero twice per cycle. Pure DC is a constant, unvarying signal. Fluctuating DC is more appropriately termed AC with a DC bias; if you remove the DC bias (by passing the signal through a capacitor, for example), you are left with a pure AC signal. Thus, an analog audio signal can be either pure AC or AC with a DC bias. But either way it's not DC, otherwise no sound would come out the speakers. So any directivilty in a speaker cable, even if we agree to suspend technical reality and say it exists, would have an affect on the sound no matter which way you turn the cable.

I must admit I'm with the Major on this one (so +1 from me) - this is how I remember it from my electronics courses. In fact, IIRC, if you pass (too much) DC down a cable to a speaker, you can damage the speaker. Now I know for long-line transmission a deliberate DC bias is applied to the line, but that isn't required in standard home set ups. Nor, do you need to have a modulated DC (DC + AC) so that the receiving end gets power, which was the approach originally used with telephones.

Reversing the signal on your speakers reverses the phase of the signal - they still work. Same for interconnects. Yes I agree, you could argue that AC is a constant alternating current signal and a in an interconnect / speaker cable you have a complex, fluctuating mix of signals - with both AC + AV.

(A "DC" amplifier is not a Direct Current amplifier, but a Direct Coupled amplifier... And amps built on these, which is/was quite common, suffer from the know disadvantage that the output contains unwanted DC (Direct Current), as well as the amplified "AC" signal)

In fact - just look here for a good summary of how amps work...

 

[MajorFubar]

The PCB's in your amps innards are fed D/C hence the use of capacitors.what's amplified and outputted is not A/C.

I'm actually going to sit and wait for you fake boffins to go read up on this and see what you come back with.

Now you're just trying to wangle out of your earlier comment where you said, obviously wrongly, that speakers were fed with DC. The closest truth is, by my primative understanding which I'm happy to let someone else correct, pure AC is a time varying electrical signal which periodically reverses it's polarity, crossing zero twice per cycle. Pure DC is a constant, unvarying signal. Fluctuating DC is more appropriately termed AC with a DC bias; if you remove the DC bias (by passing the signal through a capacitor, for example), you are left with a pure AC signal. Thus, an analogue audio signal can be either pure AC or AC with a DC bias. But either way it's not DC, otherwise no sound would come out the speakers. So any directivity in a speaker cable, even if we agree to suspend technical reality and say it exists, would have an affect on the sound no matter which way you turn the cable.

 

[MajorFubar]

That's a nice link Scene, thanks for posting.

 

[stavvy]

oops, this was meant to quote andyjm

well my point exactly, why dont they do this?! (But equally those who don't believe could prove once and for all that it makes no difference). For what its worth I'm somewhere in the middle, I believe its a good idea to shield cables and have a decent thickness of conductor, even if the effects such measures prescribe to are inaudible, but I'm just a perfectionist in that way. What I cannot fathom though is cable directionality. Ok I have no quailification in electronics or metallurgy, but I do have a degree in chemistry and I'm nearing the end of a PhD in engineering, and I just cannot see how the metal crystal structure effects the movement of electrons. Perhaps more accurately I should say at a quantum mechanical level I could believe an effect does exist, but for someone to start telling me quantum mechanics effects how a trumpet sounds....

I fancy having a go with that software, it sounds very interesting, but without a decent microphone I would always wonder how accurate it would be. Although I do have access to an anechoic chamber.....

 

[andyjm]

oops, this was meant to quote andyjm

well my point exactly, why dont they do this?! (But equally those who don't believe could prove once and for all that it makes no difference). For what its worth I'm somewhere in the middle, I believe its a good idea to shield cables and have a decent thickness of conductor, even if the effects such measures prescribe to are inaudible, but I'm just a perfectionist in that way. What I cannot fathom though is cable directionality. Ok I have no quailification in electronics or metallurgy, but I do have a degree in chemistry and I'm nearing the end of a PhD in engineering, and I just cannot see how the metal crystal structure effects the movement of electrons. Perhaps more accurately I should say at a quantum mechanical level I could believe an effect does exist, but for someone to start telling me quantum mechanics effects how a trumpet sounds....

I fancy having a go with that software, it sounds very interesting, but without a decent microphone I would always wonder how accurate it would be. Although I do have access to an anechoic chamber.....

The sceptic might say that the reason that cable manufacturers don't use Audiodiffmaker is when they tried it, the difference file was silent....

'diffmaker is usually used by recording the electrical signal rather than using a mic. Arguably a mic is the best way to do it, but if (say) the signal at the terminals on the back of the speaker is identical before and after the 'whizzbang' mains cable is used, then it is a fair assumption that the sound out of the speakers will be unchanged as well.

Any mechanical system is subject to variation, and the chances of being able to null a mic recording are much lower than monitoring the signal directly. Any change (you standing in a different position for the two runs for example) will generate a different recording. Having said that, if you do have access to an anechoic chamber you are 80% of the way there. MiniDSP in Hong Kong do a very reasonably priced measurement mic that has a USB output if you want to give it a try. If you do give it a go, please report back how you get on.

Edit: Given your background, have a look at the MiniDSP site even if you don't want the mic. These guys are doing some great stuff. No voodoo cables, just honest high level DSP in a format that is open to the hobbyist. I bought one of their early kits for fun, and can recommend them.

 

[RobinKidderminster]

The AC/DC issue is clear (DC with AC bias). Still worried which way my electrons move.

I've tried the video on my phone (an early LG clone). Admittedly at a Footy match and I could tell a huge difference. I guess quality of YouTube/equipment IS irrelevant. Sounded best before my team scored.

 

[stavvy]

oops, this was meant to quote andyjm

well my point exactly, why dont they do this?! (But equally those who don't believe could prove once and for all that it makes no difference). For what its worth I'm somewhere in the middle, I believe its a good idea to shield cables and have a decent thickness of conductor, even if the effects such measures prescribe to are inaudible, but I'm just a perfectionist in that way. What I cannot fathom though is cable directionality. Ok I have no quailification in electronics or metallurgy, but I do have a degree in chemistry and I'm nearing the end of a PhD in engineering, and I just cannot see how the metal crystal structure effects the movement of electrons. Perhaps more accurately I should say at a quantum mechanical level I could believe an effect does exist, but for someone to start telling me quantum mechanics effects how a trumpet sounds....

I fancy having a go with that software, it sounds very interesting, but without a decent microphone I would always wonder how accurate it would be. Although I do have access to an anechoic chamber.....

The sceptic might say that the reason that cable manufacturers don't use Audiodiffmaker is when they tried it, the difference file was silent....

'diffmaker is usually used by recording the electrical signal rather than using a mic. Arguably a mic is the best way to do it, but if (say) the signal at the terminals on the back of the speaker is identical before and after the 'whizzbang' mains cable is used, then it is a fair assumption that the sound out of the speakers will be unchanged as well.

Any mechanical system is subject to variation, and the chances of being able to null a mic recording are much lower than monitoring the signal directly. Any change (you standing in a different position for the two runs for example) will generate a different recording. Having said that, if you do have access to an anechoic chamber you are 80% of the way there. MiniDSP in Hong Kong do a very reasonably priced measurement mic that has a USB output if you want to give it a try. If you do give it a go, please report back how you get on.

Edit: Given your background, have a look at the MiniDSP site even if you don't want the mic. These guys are doing some great stuff. No voodoo cables, just honest high level DSP in a format that is open to the hobbyist. I bought one of their early kits for fun, and can recommend them.

Ah yes analysing the electrical signal makes much more sense. However, I may have to wangle a few favours and get into the anechoic chamber just for my own curiosity.

THe miniDSP stuff looks very interesting, it is certainly something I'm going to consider integrating into my system once I've had a chance to read a little more about it, thanks for that!!!

 

[Thompsonuxb]

The PCB's in your amps innards are fed D/C hence the use of capacitors.what's amplified and outputted is not A/C.

I'm actually going to sit and wait for you fake boffins to go read up on this and see what you come back with.

Now you're just trying to wangle out of your earlier comment where you said, obviously wrongly, that speakers were fed with DC. The closest truth is, by my primative understanding which I'm happy to let someone else correct, pure AC is a time varying electrical signal which periodically reverses it's polarity, crossing zero twice per cycle. Pure DC is a constant, unvarying signal. Fluctuating DC is more appropriately termed AC with a DC bias; if you remove the DC bias (by passing the signal through a capacitor, for example), you are left with a pure AC signal. Thus, an analogue audio signal can be either pure AC or AC with a DC bias. But either way it's not DC, otherwise no sound would come out the speakers. So any directivity in a speaker cable, even if we agree to suspend technical reality and say it exists, would have an affect on the sound no matter which way you turn the cable.

Me wangle.....never.

This may need graphs.

Your amp powers your speakers - you'll have a output Voltage on its spec sheet.

This switches on the speaker. Now your speaker being the opposite of a mic also feed from your amp. A Mic delivers its sound buy altering resistance thus increasing current and Volts etc. Fed to the amp then amplified.

Now draw a typical graph for a DC signal it operates in the + domain.

Your DC is supplied it Will raise a flat line at say 1v in the +domain (switch your speaker on) - now let's modulate it or increase voltage/current to 3v then allow it to come to rest. Rest being 1v. Still within the positive domain.

I.e what our mic does when converting sound at the other end but the opposite way around.

That's what your amp does with your speaker.

Now let's apply an AC to this.

Our graph now has 2 domains +/- . Put it on our speaker to switch it on.

It Will now see +1v
to -1v. Alternating between domains.

Your speaker will alternate between being in phase and out of phase. It'll push and pull.

It would be like constantly switching the speakers polarity.

Lol.... There are graphs and stuff on the internet I'm sure.

 

[chebby]

...Your speaker will alternate between being in phase and out of phase. It'll push and pull.

It would be like constantly switching the speakers polarity...

It does constantly push and pull, but it's doing it tens of thousands of times per second. This is why if you wire the speakers out of phase one speaker pushes while the other speaker pulls and they cancel-out each other, typically at the lower frequencies first because low frequencies have the longest wavelengths and cancel each other out more easily (plus usually they're mono).

Think of a sine wave. A pure sine wave has equal presence above and below zero:

The upper half represents +ve voltage and the lower half represents -ve voltage. The amplifier sends this out to your speakers, which typically have a coil wound around the poles f a fixed magnet which causes the coil to push out or pull back depending on the polarity of the voltage it sees. The coil is fastened to the cone, which in turn does the same thing.

 

[MajorFubar]

...Your speaker will alternate between being in phase and out of phase. It'll push and pull.

It would be like constantly switching the speakers polarity...

It does constantly push and pull, but it's doing it tens of thousands of times per second. This is why if you wire the speakers out of phase one speaker pushes while the other speaker pulls and they cancel-out each other, typically at the lower frequencies first because low frequencies have the longest wavelengths and cancel each other out more easily (plus usually they're mono).

Think of a sine wave. A pure sine wave has equal presence above and below zero:

The upper half represents +ve voltage and the lower half represents -ve voltage. The amplifier sends this out to your speakers, which typically have a coil wound around the pole of a fixed magnet. The electricity from your amp causes the coil to push out or pull back depending on the polarity of the voltage it sees, depending on whether it is attracted to or repelled by the megnet. The coil is fastened to the cone, which in turn does the same thing and creates sound. You get it? Hollar if I can help more!

 

[MajorFubar]

Nice find Chebby, picture paints 1,000 words etc...

 

[chebby]

Nice find Chebby, picture paints 1,000 words etc...

I like this better ...

http://animagraffs.com/loudspeaker/

 

[MajorFubar]

Nice find Chebby, picture paints 1,000 words etc...

I like this better ...

http://animagraffs.com/loudspeaker/

Ha! very cool. Now this might fail spectacularly but here goes:

 

[RobinKidderminster]

Blimey! How difficult is it for some to 'learn' the simple physics of loudspeaker sound reproduction? Give me a rocket scientist or brain surgeon anytime.

A good site chebby