Speaker cable length ?????

[The Grand Wazoo]

This was discussed a while back in a thread started by Howard:
http://theartofsound.net/forum/showthread.php?t=1026

.........and here's what I said...........

It's all about your ear collecting the information & your brain processing it. Now I'm a strong believer in the power of the brain to perform 'error correction' to a greater or lesser extent.

I often heard it said in relation to speakers with not much deep bass that your brain makes up for what you don't hear. I used to think that was a load of old tosh - now I'm not so sure. Of course the brain can't put the physical thump in your chest that a big speaker can, but maybe it can make you think you heard it.

Now if that's the case, then why shouldn't your brain be able to correct things like imbalances in stereo information like different lengths of cables.

If you need convincing of the power of your brain to process information and apply error correction just like a CD player then you need to read the following paragraph which staggered me & started me thinking about all this stuff..............

The phaonmneal pweor of the hmuan mind.

Aoccdrnig to rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht the frist and lsat ltteer be in the rghit pclae.

The rset can be a taotl mses and you can sitll raed it wouthit a porbelm.

Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, it lokos at the wrod as a wlohe and tehn rletaes it to the ohetr wodrs nxet to it.


.............see what I mean?

There has to be something in this don't you think?
Maybe the Dalek needs a new error correction chip?!!!

[Spectral Morn]

2 metres of cable will create an additional electrical delay of 10ns (0.01us) at most. A 2mm change in the position of the speaker will cause an acoustic delay of about 6us. The electrical delay is therefore utterly insignificant.

Having dissimilar lengths of cable may have some audible effect for two reasons. Depending on the resistance per unit length of the cable used, the variation in impedance with frequency of the speaker, as seen by the amplifier will change, and will differ for differing cable lengths in the two channels. Also the resistance of the cable effectively appears in series with the output impedance of the amplifier, so reducing the damping factor. Different cable lengths in the two channels will mean that the control of the loudspeaker by the amplifier will not be the same for each channel. It strongly depends on the speakers, cable and amplifier used. These effects may go some way in explaining the effects that Neil hears.

The change in channel balance due to resistive power loss in the cables will be quite negligable.

If you do decide to keep both speaker cables the same length, then as has been already been said, don't coil up the surplus length, rather arrange it as a loose 'zig- zag'.

In my own case the two cable lengths are roughly 17m and 8m respectively for the left and right hand channels and I have not found any problems.

Hi Barry

What a gentleman....you are sceptical but not rude in how you express your thoughts. Boy this is a refreshing change from other places...where one would be burnt at the stake. Also for you to try to offer a reason why I have heard what I have heard...thank you. I can't offer explanations for why I just know that I have heard effects/issues which exist with unequal lengths of cable and not when the cables are equal.

The Grand Wazoo This was discussed a while back in a thread started by Howard:
http://theartofsound.net/forum/showthread.php?t=1026

.........and here's what I said...........

Quote:
It's all about your ear collecting the information & your brain processing it. Now I'm a strong believer in the power of the brain to perform 'error correction' to a greater or lesser extent.

I often heard it said in relation to speakers with not much deep bass that your brain makes up for what you don't hear. I used to think that was a load of old tosh - now I'm not so sure. Of course the brain can't put the physical thump in your chest that a big speaker can, but maybe it can make you think you heard it.

Now if that's the case, then why shouldn't your brain be able to correct things like imbalances in stereo information like different lengths of cables.

If you need convincing of the power of your brain to process information and apply error correction just like a CD player then you need to read the following paragraph which staggered me & started me thinking about all this stuff..............

The phaonmneal pweor of the hmuan mind.

Aoccdrnig to rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht the frist and lsat ltteer be in the rghit pclae.

The rset can be a taotl mses and you can sitll raed it wouthit a porbelm.

Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, it lokos at the wrod as a wlohe and tehn rletaes it to the ohetr wodrs nxet to it.


.............see what I mean?

There has to be something in this don't you think?
Maybe the Dalek needs a new error correction chip?!!!
Today 12:55 AM
barry.d.hunt
Quote:

Hi Chris

The human brain is certainly capable of very great leaps in various areas. There may be something in what you say and what Howard wrote about. However why take the chance, its safer to opt for both cable lengths to be the same. Any odd things occurring are then not as a result of unequal cables.

I am confident of what I have heard, but I have an open mind and if and when I have my perceptions challenged and changed I will let AOS know.

Error correction chip......"Daleks are never in ERROR WE ARE THE SUPREME BEINGSSSSSSSSSSSSSS......EXTERMINATE." said with voice rising to a scream

Regards D S D L

[The Grand Wazoo]

Sorry Neil,
You'll have to excuse my slightly flippant response - it wasn't intended that way (but I guess you know by now, that I'm like that!!).

The human brain is certainly capable of very great leaps in various areas. There may be something in what you say and what Howard wrote about. However why take the chance, its safer to opt for both cable lengths to be the same. Any odd things occurring are then not as a result of unequal cables.

I am confident of what I have heard, but I have an open mind and if and when I have my perceptions challenged and changed I will let AOS know.

Of course, you're absolutely correct - if you can hear it, you should take steps to correct it. I can't hear it so I choose to save the cash!
Maybe with another system, or room, or other cables I might hear it.

Cheers - (Viva la difference?)

[Spectral Morn]

Hi Chris

I would have you no other way. I forgot to add a to the post.



Regards D S D L

[Ali Tait]

Hi Neil,
I hope my post didn't cause any offence,it certainly wasn't meant that way.My apologies if it did so.
I don't doubt you hear what you hear.I am interested however,in exactly what it is you're hearing,and why!
Barry's cogent reply makes a great deal of sense.Neil,have you experienced this on several different systems?

[keeper]

As its only £6 a meter I took the chance just to see.
I can't tell any difference.

Thanks for the input, at least it was all valid unlike some forums.

Now,

Should I dump the glass shelves for a home brew MDF with Acrylic supports??

A little project for the weekend to see if it helps..

Cheers Phil

[Spectral Morn]

As its only £6 a meter I took the chance just to see.
I can't tell any difference.

Thanks for the input, at least it was all valid unlike some forums.

Now,

Should I dump the glass shelves for a home brew MDF with Acrylic supports??

A little project for the weekend to see if it helps..

Cheers Phil

In a word YES. However what you could do is use RDC cones under your gear. This would remove the effect of the glass and keep the look of your table intact. Theres nothing wrong with a wee DIY project though so have a play and see how you go. If its a success maybe you might like to share your design and those inclined can try too. If you do post it in Strokes of Genius.

Regards D S D L

[Spectral Morn]

Hi Neil,
I hope my post didn't cause any offence,it certainly wasn't meant that way.My apologies if it did so.
I don't doubt you hear what you hear.I am interested however,in exactly what it is you're hearing,and why!
Barry's cogent reply makes a great deal of sense.Neil,have you experienced this on several different systems?

Hi Ali

No offence taken at all.

The opinion I have was based on experiences gained with one room and a few variations on the system I had in it. The room was very small and far from ideal. However I learnt as much as I could about the room and over time I matched room and system so they were like one.

The system was an Audio Innovations Series 500..25 watt class A valve amp, speakers Pro-ac Super Tablets, Marantz Cd 94 mk2, Speaker cable was 5m pair of Xlo type 6 and interconnects Deltec Black Slink gortex 1 m.

Any time I did anything odd/new to the system I could hear it, it was very transparent to changes even very subtle ones. The Pro-acs had/have pin point imaging and set up of them was ultra critical. If cables with one shorter run was used there would be a slight shift in the image in favour of the speaker with the shorter cable. It was obvious. Now maybe with speakers that are not quite so pin-point in their imaging or in a bigger room this may not have been quite so obvious. However I do seem to be sensitive to changes in the spatial relationship of sound in a stereo image. I can hear quite easily if a speaker is not set right as the image will sound distorted, elements more forward than they should be, the imaging will sound twisted. If the cables are not the same length, a similar effect happens in my experience.

I must be honest, and say that as I always use or recommend cables the same length I have not really played around with this in other set ups. I always feel it is best to start of with a level playing field, and in my case one of those leveling elements is having the cable lengths the same. I know cost can be an issue, and saving money is great; but in this case I just would not try it. My Atlas Marvos cable is very dear and I use 7m pairs...I could have got way with 2 M's less for the left speaker.

Its a question of logic really, and logically based on past experience it just seems better/ideal that the cables should be the same length. I can't offer measurements to validate my opinion. I just don't see why adding another variable to system set up should be done..its a risk I don't like or want to take. One thing my early system showed me is that every element of system set up is vital,and critical. The attention to small and large details will make things a total success or less so if you fail on a small point and cable length to me is a fundamentally large point.


Regards D S D L

[Marco]

Well, hi-fi theories are all well and good about why such-and-such should have an effect or not, but the proof of the pudding is always in the listening!

Although I haven't heard a difference with this myself, I agree with Neil's testing methodology. If nothing else, having equal lengths of cable removes the "What if?" factor with regard to any sonic variation between channels and gives one piece of mind knowing that this particular variable is out of the equation.

Marco.

[Barry]

First of all Neil thanks for the kind words. Yes, I am sceptical about some aspects of this hobby of ours. I suppose it’s due to my physics background and having worked in electronics research for the last 30 years. I like to think of myself as being sufficiently open minded, that if there is some explanation of some particular effect, tenuous though it maybe, I am inclined to give those are certain they can hear it the benefit of the doubt even though I cannot hear it myself. That is why I used the qualifying ‘may’ in the post. There are several reported audio ‘phenomena’ that I am extremely sceptical about: cable directionality; bi-wiring; the use of fancy (and expensive) interconnects, especially mains cables; and the use of fancy shelving systems, however I would not criticise those who feel that these items make important differences to their system – it’s their ears and it’s their money. Again in all of these cases, there are some theoretical reasons why these phenomena may (that word again) have some substance, even though I think they are small.

There is a lot we don’t understand about how we perceive sound - how the brain interprets the signals from the ears. Psychoacoustics is in relative infancy and we are still learning.

I believe your methodology to be sound: start with a level playing field, make one change and see (a) if you can hear any difference, (b) if you can, is it an improvement and (c) is the improvement maintained. I would also suggest that the human hearing is easily fooled by expectations. There have been a number of occasions where I have made a change and thought ‘that’s better’. A few days or a week later I have reversed the change and again thought things were better, so it turned out that what I thought was an ‘improvement’ was not genuine after all.

Finally one of the reasons why I joined the Art of Sound forum, is I liked the way people could hold different opinions and discuss them without the rancour and sarcasm that I have observed happening on other fora. What you seem to have here is acceptance and agreement to differ, if neither side can be persuaded by argument - with some friendly banter and gentle ‘leg pulling’. I hope it continues. We can all learn from one another.

Barry