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[PookyNMR]

I am in the process of upgrading / expanding my studio.  New cables are needed.  There is a lot of technical BS out there when it comes to cabling and I hoping that someone here can give me the straight goods.

What are some key factors to look for in good cabling?  From the research that I have done the following factors seem to be important:

-Capacitance / Resistance (what measurements should I look for?)
-Composition of conductor (any particular type, OFC, Ag, etc ?)
-Sheilding type
-Insulation type (PVC, non-PVC ?)
-Proper termination

Any specs that are optimal for audio cabling would be appreciated.  Also any hints as to what BS to watch out for would also be appreciated.

Many thanks,

Nathan

[decibel]

I can tell you that once I started using Mogami and Canare quad conductor cable, I noticed a huge difference from off-brand cables(pro co, etc....)  I think it is the Canare that uses a braided shield, and that is a real pain to work with, not impossible, but definitely cumbersome.  

In my opinion they sound really great, but I can't offer any kind of "evidence" for that.

As far as connectors, you can't really go wrong with Neutrik or Switchcraft.  The quarter inch Neutriks are really big and you have to make sure the gear will accomodate the width.

I tend to find what is well made and reliable, and stick with it.  This is the stuff that has worked for me, but I'm sure there are many other experiences and opinions on the subject.

Andy Dodd

[LumenStudio]

I'd like to know as well.  This seems to be the only forum that is really technical about things.  Much more my speed when making decisions that are not influenced by all the noise.

Much appreciated.

Cheers,
Lumen

[PookyNMR]

Andy,  

I'm pretty much sold on the Neutrik connectors.  They seem to have a great reputation among various different groups.  My expereince with them has also been very positive.

You mention the quad conductor cable.  If I'm not mistaken the theory behind that is better noise rejection.  Can you confirm that this is the case?

I've also heard reports that the Canaire cable has better noise rejection than the Mogami cable.  Your experiences?  Any measurements?

Thanks

Nathan

[Rick Sutton]

I bit the bullet and pulled out all the various types of wire my studio had been wired with over the years (from cheap crap to audiophile expensive and everything in between) and completely rewired with Mogami. Really cleaned things up sonically and organized what had been a rat's nest. Highly recommended. Used the standard (non-quad) snake cable and have no issues with cross talk or external noise.

[Brian Roth]

I've had good results with various Gepco cables.  I've also evolved to Neutrik connectors.

Bri

[decibel]

Pooky,

As far as noise rejection....just by looking at the Canare cables, they seem to be built way better than the Mogami.  The braided shield, the fabric strings as filler, ......they just "seem" to be higher quality.  That being said, I have never had noise or reliability problems with either brand.  I don't have any scientific proof, other than  the fact that I have never had to worry about noise problems.  

Canare also has a foil shield version of the quad conductor cable that they reccomend for permanent installations where you won't be bending and moving cables frequently.  That stuff is way easier to work with..


Andy

[fishtank]

In most cases I would avoid the quad conductor cable for studio wiring as it has TWICE(!) the capacitance per foot of the two-conductor version.  While it is true that the quad conductor cable may be a bit more immune to noise pickup, this is usually not a problem in a controlled environment and the potential HF roll off due to cable capacitance is not worth the tradeoff IMHO.

Jensen Transformers has some nice white papers on their website that deal with some of these issues.  Good reading.

[Bob Olhsson]

A lot of us are using digital audio wire because it has to be low capacitance. As far as I'm concerned, silver pinned Switchcraft still rules the XLR world.

[dcollins]

Bob Olhsson wrote on Thu, 09 December 2004 15:20

As far as I'm concerned, silver pinned Switchcraft still rules the XLR world.

Agreed.  With 1800F.

DC

[Rick Sutton]

Speaking of Neutrik and Switchcraft, I was putting together a DB25 to TRS snake for a remote I'm doing tomorrow night. I had some Neutrik TRS connectors that I got with some used Mogami so I used them (normally use Switchcraft). When I checked the new snake with the board I'm going to use I found that the TRS connectors didn't seat snug in the output jacks on the board. Grabbed a Switchcraft and tried it...nice and tight. The Neutriks were loose enough that I couldn't trust them so off they came and on went the Switchcrafts.
Anyone else ever notice this with Neutrik?

[PookyNMR]

Interesting that Bob mentions using digital wire for audio cables.  Is there a suggested capacitance for audio cables (with runs of 50 ft or less)?

Nathan

[fishtank]

Generally, the lower the capacitance the better.  I agree that digital audio cable would be the best choice for low capacitance, but it is about twice as expensive as normal mic cable.  I would personally opt to use the money elsewhere and just stick with good quality *normal* cable while others may feel the extra expense is worth it. With cable lengths of 50 ft or less, I would seriouly doubt that you would notice any difference between the digital cable and good quality single pair mic cable.

Here are some specs from the Markertek Catalog:

Canare DA-206 110 ohm AES/EBU cable  Cap. 14.6pF/FT  Price: .69/FT

Canare L-4E6S Star-Quad Mic cable    Cap. 46pf/FT  Price: $.36/FT

Carare L-2T2S  Single-Pair Mic cable  Cap. 22pf/FT  Price: $.35/FT

[danlavry]

PookyNMR wrote on Fri, 10 December 2004 16:13

Interesting that Bob mentions using digital wire for audio cables.  Is there a suggested capacitance for audio cables (with runs of 50 ft or less)? Nathan

A couple of comments about capacitance:

First, capacitance may be a factor at lower frequency (such as audio). At higher frequencies, unless the cable is reasonably consistent and is terminated in the proper characteristic impedance, one deal with capacitance and inductance issues. For now I will stay with audio signals (low frequencies). Clearly capacitance depends on cable type (including the various dimensions and materials) and on cable length. The key capacitance specification is typically given in pf (pico Farad) per foot.

In order to figure out the impact of capacitance on signal flatness response, one should know the source and load impedances.

Say you are driving a cable (capacitance) C. Your source is 75 Ohm resistive, and the load is high impedance. This is pretty typical to audio. Say you wish to have about 1% loss at 20KHz (less than .1dB). It would take 16200pF of capacitance to do the “specified .1dB damage”. Chances are that your cable capacitance is somewhere between 10 and 100pF per foot. Assuming 30pf/ft, it would take 162 feet for -.1dB at 20KHz.

But say you have a 5KOhm source resistance. You will now lose .1dB at 20KHz with 2.5 feet cable. In fact 54 feet will bring your 20KHz down by 3dB.

There are cases such as a high impedance transducer, a passive attenuator box and more where the cable capacitance matters in terms of amplitude response. But in most cases it is not a flatness response issue. So what is it about?

So far I only touched on the interaction of load and source with the cable capacitance.

The more important factor regarding cable capacitance is the interaction with the analog driver.

Sure it would be great to have zero capacitance, but as always, there are tradeoffs. For example, reducing the inner conductor diameter will decrease capacitance, yet you would not want to overdo it. Thicker insulation of the right material will decrease capacitance, but often as a tradeoff to another important factor.

Cable length is the one factor that is always there. The shorter, the better. In other words, if you need 10 feet, don’t have a 20 feet cable (and don’t role the access into loops, which will act like a pickup antenna).

Are you using balanced or unbalanced mode?

Regards
Dan Lavry

[locosoundman]

Great topic.  I know just enough basic electronics to get myself really confused about this.

Your source impedance is the microphone, right?  So does the impedance of the preamp figure into this at all?  Say I am going from a 150 Ohm mic to a 600 Ohm preamp (I imagine this is pretty common in most live situations with really long snake/cable runs of 100'+).  How does this work with the figures you gave before?

Since capacitances in series actually diminish as they add up, wouldn't the longer runs of cable actually have less overall capacitive reactance in their absolute impedance (total resistance would be going up, capacitance down)?  Wouldn't there also be inductances to consider in a cable of this length?


Best,
Rob

[danlavry]

locosoundman wrote on Sat, 11 December 2004 15:48

Great topic.  I know just enough basic electronics to get myself really confused about this. Your source impedance is the microphone, right?  So does the impedance of the preamp figure into this at all?  Say I am going from a 150 Ohm mic to a 600 Ohm preamp (I imagine this is pretty common in most live situations with really long snake/cable runs of 100'+).  How does this work with the figures you gave before? Since capacitances in series actually diminish as they add up, wouldn't the longer runs of cable actually have less overall capacitive reactance in their absolute impedance (total resistance would be going up, capacitance down)?  Wouldn't there also be inductances to consider in a cable of this length? Best, Rob

“Your source impedance is the microphone, right?  So does the impedance of the preamp figure into this at all?  Say I am going from a 150 Ohm mic to a 600 Ohm preamp (I imagine this is pretty common in most live situations with really long snake/cable runs of 100'+).  How does this work with the figures you gave before?”

My comments were very general. I used an example of a source with 75 Ohms source and that is a good everyday example for a line amp. I assumed the destination is high impedance compared to the source and that is a good reasonable every day assumption.
The situation regarding cable capacitance requires a case by case evaluation.

Your microphone example is one such case. Again, mics have different source impedance, certainly when going from ribbon to dynamic to condenser. The same is (or should be) for the load presented by the preamp. But the basic concepts apply.

From a circuit standpoint, the driver, cable and load are reduced to a very simple model:
A voltage source driving a network through a series resistor. The network is a capacitor (due to a cable) in parallel to a resistor (the load). The series resistor is the source resistance. Indeed it is a very simplistic model, and one can add the series resistance due to the cable, and some inductance, and skin effect, and proximity effect, and distributed line model…. And that is indeed what we do to look for finer details. For audio (such low frequencies)  the skin effect is no big deal, the inductance has minimal impact, a distributed line model is of little value. For digital audio (higher frequencies in the MHZ) I would go for a more complicated model.

“Since capacitances in series actually diminish as they add up, wouldn't the longer runs of cable actually have less overall capacitive reactance in their absolute impedance (total resistance would be going up, capacitance down)?  Wouldn't there also be inductances to consider in a cable of this length?
:?”

You are not adding capacitance in series. You are “sort of” adding it in parallel, so longer run add capacitance. Take the old capacitance model of 2 parallel plates. You get the same area wit 100 inch by 100 inch square plate, or 1 inch by 10000 plate. The later is more like a cable – narrow and long. The fact that some of the plate is 100 feet away does not matter at low frequencies because the current moves at near the speed of light – for all practical purposes, what happens at the end of the cable is as if it happened at the beginning and visa versa. Now, instead of parallel plates, think of  a circular structure of a cable. There is capacitance there.

Yes there is inductance at play, but again very small amount of it to impact the low frequencies (such as in audio). You go to higher frequencies and inductance matters a lot.

My post was only a limited reply, restricted to the issue of cable capacitance, with emphasis on if and when you get frequency roll off due to audio cable capacitance. I did not even touch on anything else, because cables are a huge subject.

I will try and find time to cover a couple of other basic factors in the unbelievably hyped and full of misinformation subject of cables. It is easier for a cable salesman to sell you on “it sound good”. You ask why, and some of the answers you get belong in the “crazy house”. So many of the statements regarding cables are presented with authority by people that know how to sell, but have less than a remote clue even of the most basic fundamentals of what is going on

Best regards
Dan Lavry  

[button]

May we hear your opinion on digital cabling?  This has also (sadly) become an *audiophile* zeppelin, inflated by the hot air of sales talk:

'the ------- allows more digital information from the source to reach the destination undistorted, and it's audible: subjectively, reduced or eliminated reflections in a digital cable is perceived as more silent background, cleaner overall sound and better "focus" and "attack"'
and
"We have brought forth a product line that is not only the Pinnacle of Accuracy  but also demonstrates the ability to deliver the ambiance of the event along with the emotion of the artist.'

And that's just the digital cables, we haven't started on the AC cords yet!

[Roland Storch]

A digital cable like AES/EBU (110?) is always also a very good connection for analog signals. It is usually just less flexible and more expensive.

I would not use it on location outside the studio because of its mechanical characteristics. But for fixed installations in bigger studios it is common practice to use only digital cables for analog and digital signals because of easier logistics.

[RMoore]

I've been using cable from Gotham - which is 'Mogami'-like, but a bit cheaper, at least over here :

http://Http://www.gotham.ch

They make all kinds of cable & formats..

There's one special double braided shield type which has improved RFI rejection..handy for mic cables.

My feeling is its easy to get hugely paranoid about cables & as long as one uses good quality eg: non-radio shack and keeps lengths short as possible its bound to be good enough for most studio needs...with the good quality ones eg Mogami, Canare, Belden , Gotham etc - it seems the main differences are marketing / pricing and ease of use like soldering, stripping the wire insulation, flexiblity of the jacket, certain formats (eg: fireproof insulation, quad, foil, shielding etc)  as opposed to any significant sonic differences.. (?)..

In my studio I used lots of Gotham cable, some Mogami and some 'recycled' Belden, some Gepco and other random cable that came with multitracks..
and even a bit of some recycled absolutely insane SILVER cable multicore from German broadcast..As opposed to being like a wire or multistrand,  its a solid thin  'rectangular' piece - like a kind of ribbon..
I get the sense you don't want to coil this stuff up or flex too many times..
Apparently it cost a <sick> fortune per meter originally..
I was lucky to score some from someone who was at the right place at the right time when stuff was getting thrown away (!)..
ahh, the practices of state funded radio & TV !

I used it on some 'critical' outboard like my best mic pres.

FWIW - the silver seemed to sound best..the Belden the least, but not 'bad'..
just in comparison.
The easiest cable to work with was the Gotham.
The worst to work with (yet 'special' in its way) was the silver, also the Mogami was a pain cuz the wire insulation is not very 'forgiving' eg: it melts back real quick down the wire..in my limited experience anyway.
The Gotham is very forgiving in that respect,

Good luck,

RM

[fishtank]

Ryan Moore wrote on Sun, 12 December 2004 12:34

I've FWIW - the silver seemed to sound best..the Belden the least, but not 'bad'.. RM

These types of statements can be dangerous.  Did you actually do a double-blind study to determine that the silver sounded better?  

One of the things I really love about this particular forum is Dan's policy about keeping things discussed here based on scientific fact.  The audiophiles always seem to sneak in and rave about some esoteric cables etc. that *seem* to sound better or how they can *sense* something above 20 KHz.

[PookyNMR]

danlavry wrote on Sat, 11 December 2004 11:53

I will try and find time to cover a couple of other basic factors in the unbelievably hyped and full of misinformation subject of cables.

That would be VERY appreciated!

danlavry wrote on Sat, 11 December 2004 11:53

So many of the statements regarding cables are presented with authority by people that know how to sell, but have less than a remote clue even of the most basic fundamentals of what is going on

That's exactly why I posted the question here.  I'd like a technical assessment of what cable properties measurements will work for my application rather than marketing BS.  And with regards to cables, there's so much BS out there, it's hard to even tell if certain advertised properties even matter.

Thanks,

Nathan

[RMoore]

<These types of statements can be dangerous.  Did you actually do a double-blind study to determine that the silver sounded better? >

Hi - thanks for bringing this up & the answer is no I didn't make any scientifically valid test or A/B comparison of any kind at all..
Actually I can't be bothered to !
Although I am concerned with good quality sound - as far as cabling goes, I am much more interested in using some quality materials that are good enough for the application & getting on with the job of recording and mixing...
Otherwise its just too easy to get confused and worry and fret excessively about 'oh jeez maybe brand X would've been .0001% better sounding..
Thats just me - Some people may feel differently.
If my business was mastering for example I would probably be paying more attention to any possible minute differences in cabling.
Anyway - in the case of the silver cable this was based on my 'memory' of how certain units in question were sounding before & after silver cable..
Hardly scientific I know..
I would be interested to know the results of any scientific study in this area. (cable comparison minus the BS and marketing hype!).
From what I understand when people have tried to do this there is little if any audible difference noticeable between quality cables - its only when its really cheap like Radio Shack or lampcord style (anyone remember the 'ol 70's trick of using AC cable for home hifi speakers?!) that anyone can hear a diff..
?
Cheers,
RM

[Sahib]

fishtank wrote on Sun, 12 December 2004 18:28

Ryan Moore wrote on Sun, 12 December 2004 12:34 I've FWIW - the silver seemed to sound best..the Belden the least, but not 'bad'.. RM These types of statements can be dangerous.  Did you actually do a double-blind study to determine that the silver sounded better?   One of the things I really love about this particular forum is Dan's policy about keeping things discussed here based on scientific fact.  The audiophiles always seem to sneak in and rave about some esoteric cables etc. that *seem* to sound better or how they can *sense* something above 20 KHz.

I completely agree on the amount of hype that is made on cables
but in terms of silver vs copper, of course silver is better as it is a better conductor than copper. Hence you do not need to see a proving formula to accept it. However, how much difference does a silver conductor make in audio frequency  and how possible it is to hear that change is another matter. But I can assure you that it would make a difference.

Cemal

[danlavry]

Sahib wrote on Mon, 13 December 2004 20:29

fishtank wrote on Sun, 12 December 2004 18:28 Ryan Moore wrote on Sun, 12 December 2004 12:34 I've FWIW - the silver seemed to sound best..the Belden the least, but not 'bad'.. RM These types of statements can be dangerous.  Did you actually do a double-blind study to determine that the silver sounded better?   One of the things I really love about this particular forum is Dan's policy about keeping things discussed here based on scientific fact.  The audiophiles always seem to sneak in and rave about some esoteric cables etc. that *seem* to sound better or how they can *sense* something above 20 KHz. I completely agree on the amount of hype that is made on cables but in terms of silver vs copper, of course silver is better as it is a better conductor than copper. Hence you do not need to see a proving formula to accept it. However, how much difference does a silver conductor make in audio frequency  and how possible it is to hear that change is another matter. But I can assure you that it would make a difference. Cemal

My ITT Reference Data For Radio Engineers tells me that resistively at room temperature (20 degree C)
Copper resistivity is 1.7241 Ohms-Cm X10^6.
Silver resistivity is 1.62 Ohms-Cm X10^6.
Gold resistivity is 2.44 Ohms-Cm X10^6.

Using copper as a reference, silver is about 6% lower and gold is about
41% higher resistivity for the SAME DIMENSSIONS.

In other words, increasing the cross sectional area by 6% will make copper resistivity equal to silver. In terms of diameter it translates to about 3% more diameter for the copper wire. In other words, just slightly thicker wire will more than overcome the material differences.

The reason I included gold is to expose some of the hype. In terms of resistance, gold is worse than copper. Of course you can add 41% more gold and be as good as copper, and it does cost money!!!

Again, one needs to examine the specific application. There are cases (very high frequencies) where the current “defies” the diameter of the material, and concentrates on the skin (skin effect), and coupled with long runs, one can loose a lot of energy. Such cases may call for silver coating. There cases where silver oxidation is not welcome and gold plating serves as protection, and so on.

For this post I am only taking about materials and resistivity.
Audio is low frequencies and one need not worry about skin effect. To say that silver vs copper matters, one needs to more than just assume that we are talking about the same exact dimensions. The basic question is at what point will the resistor begins to impact the signal.

At low frequencies, the simple model of the cable resistance is as if it were just a single resistor (component). We need to account for both signal and return path (2 wires, a wire and shield or what not). Say we have a 2 wire cable (signal and return). The wire used is 18 gauge annealed copper at room temperature (20 degree C). We get 6.4 ohm per 1000 feet in each direction, or a total of 12.8 Ohms round trip per 1000 feet. For a 16 gauge it is 8 ohms round trip and so on. So does it matter?

Clearly 12.8 Ohms is a hack of a lot if the load is an 8 Ohms speaker. Most of the energy would be wasted on the wire, and so we do not run 1000 feet of 18 gauge for speakers. But say the load is 10 KOhm. The loss in voltage is about .13% (0.011dB). That is for 1000 feet!

As a rule, at audio frequencies, high current cases call for attention to cable resistance. Sending say a 5V DC supply line to a 5 Ohm load will simply not work. But most audio cases have relatively high load impedance, where is no longer about resistance, and most often, as explained in my previous post, not about capacitance either.

I am not saying any cable is just as good as the other. I am saying: For most audio cases (low drive impedance, high load impedance) it is not about silver vs copper, or issues relating to resistivity. Of course I am assuming proper wiring of the audio cables, to carry only audio, and not be a part of some high frequency chassis return path or some AC power ground loop…

Everything I said changes at higher frequencies (MHz and above).  

BR
Dan Lavry

[LumenStudio]

Wow, lots of great info so far.  I'm really interested in this topic as I need to add additional wiring to my setup.  

So far I understand lower capicitance is better, and resistivity matters, but not enough to be concerned about (so just go with silver neutriks and be done with it).

Now if lower capacitance is better, I'd buy the digital AES cables, for all my stuff if it is that easy.  I only have a project studio and cables around here are between 5-10 ft.   I also have 3 CRT (not LCD) monitors, a few computers, a bunch of outboard gear, a digital mixer, etc.  Now with all this stuff, should I be worried about interference noise and get quad cables?  Or do I go for the lower capaitance AES cables?

Much appreciated.

Cheers,
Lumen

[RMoore]

FWIW - it strikes me that the cable subject voyages into a realm similar to 'faith' and political beliefs where there are many options but no clear single 'best way' for all people - so my thought is research what's out there, make your choice based on what seems best for you & move on to make the hits of 2005 and beyond..

RM

[locosoundman]

One more stupid question from me...

Since capacitive reactance has an inverse relationship to frequency and capacitance (I think it is -1/(6.28fc), then as frequency or capacitance increases, the overall capacitive reactance will decrease, which in my mind translates to less of an effect on the signal passing through both in phase and impedance.  Intuitively, I know this logic is wrong, I am just not sure why.

It stands to reason that cables should be transparent, but taking the above into account, if a capacitance does exist it almost seems as though a larger capacitance would be better.  Can someone please shed some light on this?

Thanks,
Rob

[danlavry]

locosoundman wrote on Tue, 14 December 2004 17:03

One more stupid question from me... Since capacitive reactance has an inverse relationship to frequency and capacitance (I think it is -1/(6.28fc), then as frequency or capacitance increases, the overall capacitive reactance will decrease, which in my mind translates to less of an effect on the signal passing through both in phase and impedance.  Intuitively, I know this logic is wrong, I am just not sure why. It stands to reason that cables should be transparent, but taking the above into account, if a capacitance does exist it almost seems as though a larger capacitance would be better.  Can someone please shed some light on this? Thanks, Rob

The general impedance is 1/sc for all signals. When you apply a sine wave of a known frequency it get simplified to 1/(i*2*pi*f*C)  and your 2*pi is about 6.28, but the i is very important (engineers often call it j), because it signifies that the impeadance is an imaginary number. Imaginary in this case means that the current leads the voltage by 90 degrees.

as frequency or capacitance increases, the overall capacitive reactance will decrease, which in my mind translates to less of an effect on the signal passing through both in phase and impedance. Intuitively, I know this logic is wrong, I am just not sure why.

It is wrong because you are viewing it as if the cable capacitance were in series with the signal. In fact it is in parallel with the load.

BR
Dan Lavry

[locosoundman]

Thanks Dan.  It goes back to the error I was making in my first post.  The capacitance is in parallel with the resistance, not in series.  Thanks for your patience.

Best,
Rob

[ssltech]

Steve Lampen at Belden has authored several excellent common-sense papers on these very issues.

An ideal cable should be low resistance, low inductance, low capacitance, just a straight black line on a schematic.

I've found that certain 110Ω digital audio cables can be microphonic in certain audio applications (load-impedance can surpress this effect to a greater or lesser extent) but generally, copper (and lots of it) is good, becoming of increasing importance where the load impedance is lower. Capacitance is bad, becoming of increasing importance where the source impedance is higher. Inductance is bad, becoming of increasing importance where the load impedance is lower.

Many domestic devices have "anti-idiot" build-out resistors so that Joe Q. Public can short left and right together to get mono, without blowing anything up and returning his "defective" CD player to best buy for a refund. Sometimes these build-out resistors, coupled to higher-capacitance cables, (often made with cheap aluminium foil conductors.. I kid you not!) can result in a loss of sonic quality (it's a simple R-C network after all). In such instances, comparing a $50 monster cable to a 25-cent cheapie cable will make you buy the monster. -Removing the build-out resistor would also have likely improved the signal with the cheap cable to about the same extent!

So the really important question is: what are the interface impedances and conditions? -That's an excellent reason why speaker cable is bad for mics (no matter what "boutique" brand you use!) and vice-versa!

Hi-Fi magazines and other works of fiction usually do not have the readership brainpower to factort in these issues, and are advertiser-influenced to the degree that they just say "Buy a $500 power cable, some $300 speaker cables, $185 interconnects, and marvel at the improvement".

Me, I say buy decent cable, use good connectors (Neutrik are innovative and convenient, but Switchcraft are electrically better... trust me!) and consider the impedances of the devices which are being connected together while making your choice.

That really is all there is to it.

The 'Voodoo' is Doo-doo!

Keith Andrews

[Sahib]

Dan,

Many thanks for the explanation. I was merely pointing out the conducting values of the silver and copper. However, I again completely agree with you that auido cable issue is greatly hyped and in most cases it turns into emperor's cloths.

Regards,
Cemal

[danlavry]

I've found that certain 110Ω digital audio cables can be microphonic in certain audio applications (load-impedance can surpress this effect to a greater or lesser extent) but generally, copper (and lots of it) is good, becoming of increasing importance where the load impedance is lower. Capacitance is bad, becoming of increasing importance where the source impedance is higher. Inductance is bad, becoming of increasing importance where the load impedance is lower.

I keep coming back to the same point: Optimizing the cable is best done when knowing the application. After talking about cable capacitance NOT being a problem for many audio applications (low impedance driver and high impedance load) I see it being interpreted as “go for low capacitance” or as “use digital audio cables”.

I think people prefer to not be bothered with having to think learn and think about details. It unfortunate, because there is no such thing as “one shoe fits all”, nor is there “one cable fits all”.

Your comment about microphonics is a good example. A cable carrying DC signal can respond electrically to mechanical disturbance (such as tapping or moving). The mechanism is similar to the operation of a condenser mic – parallel pieces of metal (2 wires or a wire and shielded) are in fact a capacitor. A DC charge on a cable between the conductors will generate an ac (signal) voltage when one changes the distance between the conductors, such as when tapping on the cable.

Normally, such microphonics is more offensive when the signal level is low and will be amplified (such as cables for microphone applications). It is wise to avoid DC on cables but in some cases such as condenser mics there is a lot of DC (48V), thus no escape from DC.  So a more “solid” cable may be of benefit for high DC voltage case. Again, one can approach or supplement a solution for DC micophonics by protecting the cables from mechanical motion.  

The other factors affecting the DC voltage microphonics are the parallel combination of source resistance and load resistance. If we have low impedance (resistance) than the ac voltage due to mechanical motion (microphonics) will be lower amplitude. But it is best to have a low source resistance, and a high load resistance. Adding additional load is not very effective, because the discharge path for the audio signal is almost completely determined by the much lower impedance at the source side (often in the 75 Ohms range), unless you are ready to go to very low resistance load (very bad idea in general).

There are other factors impacting DC voltage microphonics, mostly mechanical. Generally speaking you want a cable with a greater distance between the conductors, and the material to be of low dielectric constant. These are the same factors that make for low capacitance cable. Low capacitance tends to yield low “change in capacitance” due to mechanical causes. We want to minimize the change in capacitance. And of course, as always, the longer the cable, the more charge thus the more microphonics…

   
Regards
Dan Lavry

[fishtank]

Sahib wrote on Mon, 13 December 2004 20:29

I completely agree on the amount of hype that is made on cables but in terms of silver vs copper, of course silver is better as it is a better conductor than copper. Hence you do not need to see a proving formula to accept it. However, how much difference does a silver conductor make in audio frequency  and how possible it is to hear that change is another matter. But I can assure you that it would make a difference. Cemal

I was well aware of the fact that silver is a better conductor than copper.  The point I was attempting to make is that I seriously doubt there would be an audible difference between good quality copper cable and the overpriced audiophile silver stuff. Just because one person claims it *seemed* to sound better is not convincing to me. I never stated there would be NO differences in electrical properties (however slight they may be).

There is much more to microphone or line level cable performance than resistance of the conductors, not to mention the fact that a larger diameter copper conductor could have less resistance than a smaller silver one.  I would personally choose low capacitance and good shielding over conductor resistance.

[ssltech]

Absolutely.

In fact nothing is of greater influence than the nature of the boundary between source and destination, and this is the exact boundary at which the cable lives. When "Mega-brand corporation" wants to dempnstrate their "superior" cables they naturally choose source and load impedances which show their products in the best light... and I can't condemn them for that, anyone in their right mind would!

It becomes a problem when people over-simplify, and take away only a "Mega-brand good, cheap bad" distillation. Couple with this what a wise-old-owl mother of an ex Girlfriend of mine used to say: "People of no discernment cannot afford to buy cheap" and you have a simplistic reduction that some brands cannot be good, others cannot be bad.

Here's a couple of links to some of Steve Lampen's stuff, in case it helps anyone else to think for themselves!

http://www.rwonline.com/reference-room/wired-4-sound/rwf-lam pen-08.15.01.shtml

http://www.rwonline.com/reference-room/wired-4-sound/rwf-lam pen2.shtml

http://www.hpaonline.com/files/public/CoaxHistoryVideo.pdf

Keith Andrews

[Sahib]

fishtank wrote on Tue, 14 December 2004 19:01

Sahib wrote on Mon, 13 December 2004 20:29 I completely agree on the amount of hype that is made on cables but in terms of silver vs copper, of course silver is better as it is a better conductor than copper. Hence you do not need to see a proving formula to accept it. However, how much difference does a silver conductor make in audio frequency  and how possible it is to hear that change is another matter. But I can assure you that it would make a difference. Cemal I was well aware of the fact that silver is a better conductor than copper.  The point I was attempting to make is that I seriously doubt there would be an audible difference between good quality copper cable and the overpriced audiophile silver stuff. Just because one person claims it *seemed* to sound better is not convincing to me. I never stated there would be NO differences in electrical properties (however slight they may be). There is much more to microphone or line level cable performance than resistance of the conductors, not to mention the fact that a larger diameter copper conductor could have less resistance than a smaller silver one.  I would personally choose low capacitance and good shielding over conductor resistance.

I completely agree with you fishtank. I stated in my previous post that this issue is like the emperor's clothes. I am surrounded by audiophiles who pay stupid amount of money to cables. In fact I have witnessed somebody upgrading a speaker cabinet internal connections with silver wire and then turning the volume up and saying how the bass frequencies became deeper with a smile on his face. I am sure it made a difference in conducting the signal butI did not hear a damn difference sonicaly.

[PookyNMR]

My brother, having done some testing, did find a measureable difference with silver conductors.  He found increased high frequency transmition over oxygen free copper.  This was a few years ago so I don't remember his exact measurements.  I don't quite understand how this could be, but those were his results.

Nathan

[bobkatz]

ssltech wrote on Tue, 14 December 2004 13:01

I've found that certain 110? digital audio cables can be microphonic in certain audio applications (load-impedance can surpress this effect to a greater or lesser extent) but generally, copper (and lots of it) is good, becoming of increasing importance

You mean, as an analog interconnect, I'm sure. If the cable is microphonic wouldn't that imply a non-constant impedance as you move the cable around or even tap on it? Then it wouldn't make a very good digital cable, either.

If you mean microphonics when used with microphones, I can thoroughly understand, because these cables are very stiff by their very design and would pass physical shock onto the microphone. Not a good thing.

BK

[RMoore]

ssltech wrote on Tue, 14 December 2004 19:01

Me, I say buy decent cable, use good connectors (Neutrik are innovative and convenient, but Switchcraft are electrically better... trust me!)   Keith Andrews

Curious - Why are Switchcraft better electrically?
FWIW I find the Neutriks are 5 million x more convenient than having to unscrew tiny screws Switchcraft style..
Thanks in advance!
RM

[Bob Olhsson]

The classic Switchcrafts are much more rugged. Silver oxide is a better conductor than gold and in most cases the silver is lots thicker than typical gold flashing.

Everybody finds Neutriks 5 million x more convenient until the first time one fails! My friends ALL went back to Switchcraft after a brief fling with Neutriks.

[RMoore]

Yikes! OK, thanks for the info,
all the best,
Ryan

[PookyNMR]

danlavry wrote on Tue, 14 December 2004 12:00

[There are other factors impacting DC voltage microphonics, mostly mechanical. Generally speaking you want a cable with a greater distance between the conductors, and the material to be of low dielectric constant. These are the same factors that make for low capacitance cable.

Interesting that you mention the dielectric constant.  I read an article from a fellow from Gepco that mentions the importance of keeping this constant low by using some materials and avoiding others.  If I understand correctly what he was saying, the dielectric constant also plays a factor in noise rejection.

Nathan

[danlavry]

PookyNMR wrote on Sat, 18 December 2004 07:32

danlavry wrote on Tue, 14 December 2004 12:00 [There are other factors impacting DC voltage microphonics, mostly mechanical. Generally speaking you want a cable with a greater distance between the conductors, and the material to be of low dielectric constant. These are the same factors that make for low capacitance cable. Interesting that you mention the dielectric constant.  I read an article from a fellow from Gepco that mentions the importance of keeping this constant low by using some materials and avoiding others.  If I understand correctly what he was saying, the dielectric constant also plays a factor in noise rejection. Nathan

As far as I know, the dielectric constant effects only the electric field, therefor the capacitance. It does not impact the magnetic field strength. I do not see how it can impact noise. Where is that article?

Regards
Dan Lavry  

[Spaceman]

Since we're discussing cables here I just wanted to mention some mic testing research that I just completed.  You can find the complete post in the product review section here at the forums. (topic: The question everybody asks but no one answers) Read the entire thing though before you decide me to be shill!

[danlavry]

Spaceman wrote on Mon, 20 December 2004 20:59

Since we're discussing cables here I just wanted to mention some mic testing research that I just completed.  You can find the complete post in the product review section here at the forums. (topic: The question everybody asks but no one answers) Read the entire thing though before you decide me to be shill!

I appreciate the fact that it took time and that you want to share. However in this forum we try and stay technical, away from opinions based on listening, subjective remarks and specific gear recommendations.

Regards
Dan Lavry

[PookyNMR]

danlavry wrote on Mon, 20 December 2004 13:45

As far as I know, the dielectric constant effects only the electric field, therefor the capacitance. It does not impact the magnetic field strength. I do not see how it can impact noise. Where is that article? Regards Dan Lavry

Dan,

Found the article.  It is by Joseph DiBenedetto.  He said:

Along with twisting and shielding, the dielectric is an instrumental factor in the performance of the cable.  The dielectric in the cable is the insulation that coats each conductor, electrically separating the conductors from each other and the shield.  When the signal travels down the copper conductor, it will actually be ?absorbed? through the dielectric and into the shield.  This occurs to a greater effect at higher frequencies.  Typically, you should look for a dielectric with a low k constant. ?For the dielectric, you should choose a solid polyethylene, foam polyethylene or foam polypropylene compound,? Fehl explained.  ?Stay away from PVC-type compounds because the dielectric constant is higher.  The lower the dielectric constant, the lower the high-frequency attenuation.?

Apparently, I got my info mixed up with other info.  The importance of the constant had to do with high frequency attenuation.

Nathan

[danlavry]

PookyNMR wrote on Tue, 21 December 2004 05:53

danlavry wrote on Mon, 20 December 2004 13:45 As far as I know, the dielectric constant effects only the electric field, therefor the capacitance. It does not impact the magnetic field strength. I do not see how it can impact noise. Where is that article? Regards Dan Lavry   Dan, Found the article.  It is by Joseph DiBenedetto.  He said: Along with twisting and shielding, the dielectric is an instrumental factor in the performance of the cable.  The dielectric in the cable is the insulation that coats each conductor, electrically separating the conductors from each other and the shield.  When the signal travels down the copper conductor, it will actually be ?absorbed? through the dielectric and into the shield.  This occurs to a greater effect at higher frequencies.  Typically, you should look for a dielectric with a low k constant. ?For the dielectric, you should choose a solid polyethylene, foam polyethylene or foam polypropylene compound,? Fehl explained.  ?Stay away from PVC-type compounds because the dielectric constant is higher.  The lower the dielectric constant, the lower the high-frequency attenuation.? Apparently, I got my info mixed up with other info.  The importance of the constant had to do with high frequency attenuation. Nathan

OK. That makes sense. Noise reduction? NO. High frequency characteristics? Yes. I can appreciate the comments for high frequencies, way above the audio range. I do not see it as a factor for audio. The higher dielectric constant yields more capacity, and we already talked about capacitance, and how too much capacity in the presence of high impedance may cause a low pass filter effect. This is not normally the case. But the material properties Fhel is talking about is at much higher frequencies, not audio.

Regards
Dan Lavry