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professorhat's picture
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RE: cable sceptics give us your experiences !

andyjm wrote:

What else would we post about? The weather?

Not great at the moment is it? Mind you, just came back from honeymoon in Europe and in Rome and it tipped it down on Monday. So.

 

The owls are not what they seem...

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RE: Mike, you are a brave fellow.

andyjm wrote:

mikefarrow wrote:

thanks for your input trevc !

when i swapped the free "kettle lead" cable on my intergrated amp for a much thicker russ andrews signature cable the sound improved in all areas but mainly in the bass output of my system which became louder/fuller (?)

this is apparently due to the lower resistance that this thicker cable has hence it supplies the amp with power more easily.

wether this is true/the actual reason, i wouldnt know - i just know that this mains cable performs better than the free one !

Mike,

You are of course free to believe what you like, but that mains cable isn't impacting the bass response of your amp in any way. 

At a stretch, under very contrived circumstances, changing a mains cable MAY make a difference to the the pickup of stray RF (it can act as an aeriel), and if the amp has been designed very badly, this may eventually find its way to the output and possibly increase background noise. Nothing you are going to do to your mains cable (apart from disconnect it) will impact the bass response of your amp.

The technical explanation:

Mains is AC, your amp runs on DC.  The mains waveform is a sine wave, 50 complete waves per second. This is useless to power an amp, it is the wrong voltage, and needs to be rectified and smoothed.

The power supply in your amp first reduces the AC voltage through a transformer. This is then rectified through a bridge rectifier.  Instead of an AC waveform going positive and negative, the rectified signal now only has positive going pulses, 100 per second. This is still useless to power an amp, and has to be smoothed by a storage capacitor to fill in the gaps between the pulses.  The following link has a good explanation of this and diagrams of the waveforms.  Scroll down to "Full Wave Rectifier Waveforms":

  http://www.electronics-tutorials.ws/blog/unregulated-power-supply.html

So, lets imagine that a bass drum kick comes along to be amplified, and it just happens to coincide with the point that the mains AC waveform is zero.  What happens?  The amp can't draw power from the AC supply, at this instant, there isn't any to be had. It draws power from the storage capacitor. The best analogy is to think of the storage capacitor as a bucket, the amp is fed from a hole in the bottom of the bucket by a steady stream, the AC waveform comes along from time to time to slosh some more water in the top of the bucket.

The point is that instantaneous power demands are met by the storage capacitiors in the power supply, not the mains AC waveform (how could it if it is zero?). The AC waveform supplies the AVERAGE power used by the amp, not the instantaneous peaks. The average power demand from an amp is very low, just a few 100's of watts at the most - even with very inefficent designs (most of the supply gets given off as heat, and doesn't find its way to the speakers) - your wife's hairdryer will draw many, many times the power of your amp.

So, how can changing the mains cable make any difference to the instantaneous power available in the amp to improve bass response?

It can't. 

 

 

Bravo. Now let's have no more of this nonsense.

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RE: cable sceptics give us your experiences !

RobinKidderminster wrote:

So, Andy, you have no 'respect' for publications finding clear differences between speaker cables, hdmi cables etc? And therefore would find any reviews of little value? (Devils advocate)  Smile

 

There are differences between speaker cables. Ones that are higher resistance will sound worse, and this is entirely predictable.

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RE: cable sceptics give us your experiences !

RobinKidderminster wrote:

So, Andy, you have no 'respect' for publications finding clear differences between speaker cables, hdmi cables etc? And therefore would find any reviews of little value? (Devils advocate)  Smile

 

No, unless they do proper blind tests.

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RE: cable sceptics give us your experiences !

RobinKidderminster wrote:

So, Andy, you have no 'respect' for publications finding clear differences between speaker cables, hdmi cables etc? And therefore would find any reviews of little value? (Devils advocate)  Smile

To be clear, there are differences between cables of vastly different thickness. Wierdo weaves will be different to plain side by side. What won't be different are cables of approximately the same thickness and construction - as most speaker cables are, so generally the differences in cables are imagined.  I would have a lot more respect for cable reviews if they published conductor cross sectional area, and the three basic conduction parameters - resistance, capacitance and inductance so we could compare properly.

Editorial in mags is to fill the gap between the adverts and to draw the punters in, not to search for the greater truth.  I have some sympathy for their plight, circulation is under pressure and the web doesn't have the same revenue model for them.

I do think however that mags got caught out by the introduction of digital audio - some of the hyperbole that used to be just about acceptable for an analogue system became laugable for digital systems. The journalists didn't understand the technology, and the reviews of HDMI leads, SATA cables (you know who you are..) and the such like became the laughing stock of anyone who knew anything about how the systems worked. 

I think that generally such nonsense has been ridiculed into silence.

 

 

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RE: cable sceptics give us your experiences !

Thanks Andy. I recon yr reply concisely summarises the situation.  Smile

Yamaha V2065. MS Mezzo 5.1 Panasonic 42. Sony BD. Garrard 86SB. WD Live TV. SkyHD.

http://www.whathifi.com/forum/home-cinema/lounge-hc-signature-update-bass-traps

 

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RE: Mike, you are a brave fellow.

TrevC wrote:

andyjm wrote:

mikefarrow wrote:

thanks for your input trevc !

when i swapped the free "kettle lead" cable on my intergrated amp for a much thicker russ andrews signature cable the sound improved in all areas but mainly in the bass output of my system which became louder/fuller (?)

this is apparently due to the lower resistance that this thicker cable has hence it supplies the amp with power more easily.

wether this is true/the actual reason, i wouldnt know - i just know that this mains cable performs better than the free one !

Mike,

You are of course free to believe what you like, but that mains cable isn't impacting the bass response of your amp in any way. 

At a stretch, under very contrived circumstances, changing a mains cable MAY make a difference to the the pickup of stray RF (it can act as an aeriel), and if the amp has been designed very badly, this may eventually find its way to the output and possibly increase background noise. Nothing you are going to do to your mains cable (apart from disconnect it) will impact the bass response of your amp.

The technical explanation:

Mains is AC, your amp runs on DC.  The mains waveform is a sine wave, 50 complete waves per second. This is useless to power an amp, it is the wrong voltage, and needs to be rectified and smoothed.

The power supply in your amp first reduces the AC voltage through a transformer. This is then rectified through a bridge rectifier.  Instead of an AC waveform going positive and negative, the rectified signal now only has positive going pulses, 100 per second. This is still useless to power an amp, and has to be smoothed by a storage capacitor to fill in the gaps between the pulses.  The following link has a good explanation of this and diagrams of the waveforms.  Scroll down to "Full Wave Rectifier Waveforms":

  http://www.electronics-tutorials.ws/blog/unregulated-power-supply.html

So, lets imagine that a bass drum kick comes along to be amplified, and it just happens to coincide with the point that the mains AC waveform is zero.  What happens?  The amp can't draw power from the AC supply, at this instant, there isn't any to be had. It draws power from the storage capacitor. The best analogy is to think of the storage capacitor as a bucket, the amp is fed from a hole in the bottom of the bucket by a steady stream, the AC waveform comes along from time to time to slosh some more water in the top of the bucket.

The point is that instantaneous power demands are met by the storage capacitiors in the power supply, not the mains AC waveform (how could it if it is zero?). The AC waveform supplies the AVERAGE power used by the amp, not the instantaneous peaks. The average power demand from an amp is very low, just a few 100's of watts at the most - even with very inefficent designs (most of the supply gets given off as heat, and doesn't find its way to the speakers) - your wife's hairdryer will draw many, many times the power of your amp.

So, how can changing the mains cable make any difference to the instantaneous power available in the amp to improve bass response?

It can't. 

 

 

Bravo. Now let's have no more of this nonsense.

Andyjm's explanation would be rather more convincing if he did not gloss over the one aspect of this debate that is known to make an audible difference, ie Radio Frequency Interference.

I have owned, in recent years, a Plasma TV and two dacs that have an effect on the sound of my system when plugged in and switched on, they do not even have to be connected to the system for this to occur. 

Whilst not formally qualified in this area I have hunted down RF problems in many studios, theaters and homes and radiated RF around a sysyem can be considerable, dropping off with distance. My plasma for example, in it's normal position on top of the equipment cabinet, was quite clearly audible as an increase in the noise floor on my system, quite obvious.

This is an area that has had very little attention, Paul Miller, did some work on this in the 90's, showing how equipment reacted in different ways to the presence of RFI, it was not at all complimentary to some products but has been somewhat swept under the carpet since.

If the RFI is airborn rather than being transmitted through the mains then it is possible that, in the critical area around the equipment, different mains cables could react differently in their susceptibility to RFI and this could be audible.

 

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RE: cable sceptics give us your experiences !

so that's the noise floor, but what impact is this going to have on bass or treble? It won't increase or decrease the amount of either, will it? I mean, one of the problems of vinyl is surface noise, but it's only the silences, not the frequency response, that is affected.

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RE: cable sceptics give us your experiences !

andyjm wrote:

mikefarrow wrote:

calling all cable sceptics, please detail your experiences with expensive cables and hence give reason for your scepticism weight !

include mains as well as interconnect/speaker cables tested including models tried plus models currently in use in your system.

please only reply if you have tried more expensive offereings giving your actual experiences - no comedians who have not tried pricer cables thanks !

Of course speaker cables make a difference.  Try replacing your cables with thin bell flex, you will notice a change.

 

that's signal lost not actually changing the sound as I thought we was discussing? 

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RE: cable sceptics give us your experiences !

altruistic.lemon wrote:

so that's the noise floor, but what impact is this going to have on bass or treble? It won't increase or decrease the amount of either, will it? I mean, one of the problems of vinyl is surface noise, but it's only the silences, not the frequency response, that is affected.

Morning Al.

Actually it just might, RFI induced noise can also manifest itself on the output as a kind of hazy, gritty quality to the sound, that in effect makes the component sound 'brighter', which can be interpreted as 'less bass'.

The effect on the noise floor is one of the simplest ways to hear RFI, just turn the system up, no signal, and make some changes, but it is not the only way it's effects can be heard.

Okay, I freely admit that what I am discussing here are effects that only affect some systems in some circumstances and that the most of the usual observerd differences between cables, power in this case, are nonsense.

However it does make the blanket assertions that it can't make a difference a bit difficult for me.

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RE: cable sceptics give us your experiences !

professorhat wrote:

andyjm wrote:

What else would we post about? The weather?

Not great at the moment is it? Mind you, just came back from honeymoon in Europe and in Rome and it tipped it down on Monday. So.

 

 

I was in the Cotswolds last week and the mornings were very foggy before clearing into warm weather by lunchtime. Now I'm back in Manchester it's grey and rainy again. That's our Indian summer over then. 

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RE: cable sceptics give us your experiences !

professorhat wrote:

andyjm wrote:

What else would we post about? The weather?

Not great at the moment is it? Mind you, just came back from honeymoon in Europe and in Rome and it tipped it down on Monday. So.

Congratulations Prof.All the best to you both.

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RE: cable sceptics give us your experiences !

Ravey Gravey Davy wrote:

professorhat wrote:

andyjm wrote:

What else would we post about? The weather?

Not great at the moment is it? Mind you, just came back from honeymoon in Europe and in Rome and it tipped it down on Monday. So.

Congratulations Prof.All the best to you both.

congratulations.  Shame about the weather, hopefully you had better days.  For added outdated humour, surely you only noticed the weather from the room window???

Apple lossless - Netgear Nighthawk - ATV3 - AVI ADM 40.  

AVI ADM 9T used in my wife's system

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RE: cable sceptics give us your experiences !

All these discussions about cables are so pointless. 

-Buy expensive cables if you think they will make a difference. 

-Use cheap cables if you think more expensive cables will not make a difference.

Life can be so simple  Wink

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RE: cable sceptics give us your experiences !

relocated wrote:

Ravey Gravey Davy wrote:

professorhat wrote:

andyjm wrote:

What else would we post about? The weather?

Not great at the moment is it? Mind you, just came back from honeymoon in Europe and in Rome and it tipped it down on Monday. So.

Congratulations Prof.All the best to you both.

 

congratulations.  Shame about the weather, hopefully you had better days.  For added outdated humour, surely you only noticed the weather from the room window???

Grey overcast but slowly brightening here in west London.

However the day brightened considerably a few minutes ago with a group (flock?) of eight green parakeets cavorting around just outside my second floor window, the balcony doors were wide open and their noise attracted my attention.

Like these...

 

 

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