Sonic difference between cheap and more expensive MIC CABLES?

[Bob Olhsson]

Go where the pros go:

America's Broadcast | Pro-Audio | New Media Supply House

[digibird]

...hoping my latest Redco order arrives tomorrow (six channel snake to use A Designs ATTY2'D with API 3124 & GR MP2NV)...always happy with their work and their prices are very reasonable for the quality they provide.

1-800-572-7280 ext. 104 = Chris

[salvomix]

AAAhhh. speaker cables make a huge difference!

I was at a shoot-out once and Zaolla smoked everyone! It was scary to hear such a difference!

www.salvomix.com

[Drumminkiger]

Originally Posted by dementedchord

you're kidding right???? if not i susgest you take some electronics classes....

If you dont buy it, get out a multimeter and check it out yourself. In my experiance, its been true. (and i did take an electronics class, its where i learned how to build cables, not that it makes me any better at it then a monkey with a soldering iron lol )

[dementedchord]

Originally Posted by Drumminkiger

If you dont buy it, get out a multimeter and check it out yourself. In my experiance, its been true. (and i did take an electronics class, its where i learned how to build cables, not that it makes me any better at it then a monkey with a soldering iron lol )

well evidently they didn't explain to you that the loss of a resistive load is proportional in nature... and it's perception is logrythmic... as an experiment take a dual trace o'scope and hook it on both sides of your mic cable... see any difference??? i doubt it... now invert one side and sum the inputs... dont be surprised if you have to change the input sensitivity to 100-1000X's in order to see the difference....

[Drumminkiger]

The way it was explained to me is that it had more to do with the fact that the cheap cables use crumby connectors, and that machine solder joints are not as good as the ones done by humans. either way, poorer connections add up to more loss of signal. I can detect the differances on a cheap radioshack pocket multimeter (and the differance is greater on a more accurate meter), including the small differances between cables i build that are made with the same components, its all in how cleanly the soldering and stripping of the wires are done. Even mogami isnt going to pay someone to hand strip and solder all of their wires, they are just going to buy a macine to do it, and the wire they use with machine built cables does not have the supirior braided shielding because unbraiding it to solder the ends on would not be cost effective. Im no electronics wiz, but it makes sense to me without my teachers explination why some cables are better then others, and why these building factors are crucial to minmizeing transmission loss. Its really not rocket science, its a cable.

[PepsiFX357]

When switching from hosa cables to building my own Mogami/Neutrik cables from REDCO, I noticed a pretty significant difference in high frequency and volume. Clarity basically.

[scrubs]

If no one has mentioned it, Audiopile Pro Audio* Welcome to Audiopile has inexpensive cables that are well built and sound every bit as good as mogami/monster/etc., imo.

[nosebleedaudio]

In my 30+ years I have seen a lot of low end cables either go bad or cause noise ect just sitting there. IM talking about in a fixed studio environment.
Engineers are always confused; this is one of many reasons that most use good cables in the first place...
And its the cable, NOT the connectors that make the biggest difference...

[dementedchord]

Originally Posted by Drumminkiger

Its really not rocket science, its a cable.

sorry... but you still miss my point... given a mixer and/or pre with an input impedence of say anywhere from 600-2.2k ohms... it's absurd to expect an audible difference in cables owing to a resistive varience between .5-5ohms as you claimed you've seen in your cables... i dont doubt there's some difference in the resistence you read on your meter... just that it's so little relative to the overall impedence of the circuit as to be inaudible... if you think you hear a diff... so be it... but it ain't from resistence differences....

[svart]

that machine solder joints are not as good as the ones done by humans. either way, poorer connections add up to more loss of signal.

I work in RF design, broadband over coax to be more specific.

Let me tell you about cables and robotic placing/soldering..

First off, I've been working in the electro-mechanical industry for years and have yet to see a robot that can solder cables. This has always been done by hand and as far as I know, will always be done by hand. And what poor connections do you speak of? A solder joint is either connected or it's not. there is no transimpedance region for solder. A broken solder joint will corrode and the oxide on the edges of the cracks will create a capacitor-like effect where extremely low level audio will jump this gap and create a passive filter of sorts.. sometimes.

Second, machine placing/soldering has been superior to hand soldering for years. A machine can follow precise heating requirements that humans simply cannot match time after time without changes in consistency. Now if the human who programmed the machine is not competent then the machine will not work as expected.

Trust me, slow audio frequencies have no trouble traveling over cheap audio cables. The RF stuff I get into is designed around transmitting GHZ RF through LONG(think miles and miles) of crumby cable with likely corrosion/water ingress etc. If I can get a QAM-256 transmission from point A to point B and still get an acceptable S/N(we call it MER) then your audio will suffer no problems through 15ft of cheap copper.

That being said, if a little resistance/impedance and/or capacitance can tangibly impact your audio quality then you don't have a problem with your cable, you have a problem with SEVERE impedance mismatch AND/OR poorly designed drivers/receivers on the ends of your cables.

I bet there are folks who actually believe that electrons/holes bunch up in corners too..

[tINY]

Originally Posted by svart

I bet there are folks who actually believe that electrons/holes bunch up in corners too..

Won't skin effect cause exactly that in conductors with square profiles?




-tINY

[deve]

Good cables and good connectors are a must in a studio. When you have a problem in your signal path, you know that it's not the cable and don't loose valuable time swapping cables. I use Gotham cables and neutrik connectors for mic cables and planet waves for instrument cables. +1 for redco.

[DamnYankee]

It looks like your teacher gave you some bad information. All things being equal (same connectors, etc), you will not hear a difference between hosa & mogami/canare/belden because conductance (ease of electrons to flow) of copper is extremely high; only silver has higher conductance (copper wire vs silver wire and its impact on perceived audio quality is a completely different debate).

Also, I disagree with your machine vs human solder joints argument.

IMHO, the reason some cables are better than others boils down to application: the right gauge wire and right shielding for the right job.

Originally Posted by Drumminkiger

The way it was explained to me is that it had more to do with the fact that the cheap cables use crumby connectors, and that machine solder joints are not as good as the ones done by humans. either way, poorer connections add up to more loss of signal. I can detect the differances on a cheap radioshack pocket multimeter (and the differance is greater on a more accurate meter), including the small differances between cables i build that are made with the same components, its all in how cleanly the soldering and stripping of the wires are done. Even mogami isnt going to pay someone to hand strip and solder all of their wires, they are just going to buy a macine to do it, and the wire they use with machine built cables does not have the supirior braided shielding because unbraiding it to solder the ends on would not be cost effective. Im no electronics wiz, but it makes sense to me without my teachers explination why some cables are better then others, and why these building factors are crucial to minmizeing transmission loss. Its really not rocket science, its a cable.

[Drumminkiger]

I dont think his information is entirely incorrect, he has a BA in electronics engineering on top of being a great seasoned audio engineer (We called him grandpa at school because he's been in the bizz since 1974). My main point with all of it was, say you have a low level source like a ribbon mic and then you run that signal through a cable with higher resistance, you're alredy low level signal will come through that cable into your mic pre at an even lower level (meaning less volume getting to your mic pre). Then you have to crank up your mic pre higher to get the same level into your recorer. Is that a sonic differance? I suppose that is open to inturpritation, but to me it is because it means you have to add more gain and it will amplify any other noise that that cable is picking up along the way as well as your source. I would imagine that with a line level source like an RF signal this would be less of a factor because you're not gaining it up as much on the other end correct? Cheap cableing is a plauge to any studio, and my main point to all of this was that for the same money as hosa, you can have high quality cables to interface your gear that will last a long time, and deliver you good signal. I highly doubt any claim that a cable built with poor components is equal in quality to a cable built with premium components. Maybe intially there will be very little differance, but with some use that will become much greater as my experiance (and im sure many other engineers who have used bargin brand cables) has proven to me.

[tINY]

I have to disagree with your conclusion.

For 95% or more of the situations you run into, the "cheap" cable performs nearly exactly as well as the more expensive "standard" cable. It will fail sooner.

If the new, cheap stuff is having problems, it's a situation where you really need specialty cable anyway...

Oh, be aware: Hosa has some really cheap stuff with molded connectors and thin wire. This is the "cheap stuff" I think of. There are Hosa products where decent (but less robust) cable is hand soldered to cheaper connectors. Other than some mechanical fit issues on occasion, these are actually pretty decent - especially considering what you can talk the price down to.




-tINY

[Beyersound]

Originally Posted by Sounds Great

Cheap cable has more resistance? Where did you get that from?

Now, it they have failing parts, that could be true, which is why to stay away from Hosa. But as far as the cable itself, there is no correlation to cost and resistance level.

I'm with you on resistance. Don't forget there is a pretty big difference in capacitance between cheap cable and Mogami, Canare, etc, which will DEFINITELY affect the sound. There is also a big difference in noise and rejection with premium cable. I also strongly urge you(Theoneandonly) to build your own cables, it's easy to learn and you can build a 10' cable of Canare Starquad cable and Neutrik connectors yourself for about $9-10 or a 25' for about $16-17 if you shop around. Be glad to tell you where to get the stuff cheap if you want.

[Francis Vaughan]

So, where angels fear to tread.....

Cables really get an astounding amount of attention, and so much pseudo-science and snake oil is about that it becomes impossible. What is worse is that the amount of half truths with the science makes is ever harder to winnow out the crud from the reality.

So, there are a lot of interesting possible effects in cables. If you can conceive of an effect it probably has been touted as an important design issue by some cable purveyor
at some time or another. Sadly what is usually missing is any evidence, or even simple calculation of the probable magnitude of the effect.

So, a few effects and likely impact.

Resistance. As has been pointed out, there is scant reason to believe that signal attenuation doe to resistance has any effect. Even if the source impedance is low (like a ribbon mic) the input impedance of the mic pre is still vastly higher, and the effect of a few ohms series resistance miniscule.

Skin effect. The all time favourite. Only trouble is, is that at audio frequencies the skin effect is a non starter. Skin depth - the depth at which the conductivity halves - for copper at 20-kHz is 0.46mm and at 100-kHz is 0.2mm. The usual design rule for skin effect is to use a conductor with a diameter 5 times the skin depth (after which you are wasting metal.) So there is really no possible issue with a conductor 2.5mm in diameter - which is pretty big. If you want to go to 100kHz, 1-mm is still a very thick conductor. Even when it gets thicker than these numbers the actual change in frequency response is miniscule in the extreme. This hasn't stopped an insane number of cables being marketed that claim to address skin effect in some form. This includes claims of cable with different diameter strands (the bass goes down the thick strands, the treble through the thin ones.) Utter tosh. Also Litz stranded wire. Sure Litz is important at RF, but the stuff sold as Litz usually isn't even real Litz construction. And so it goes.

Microcrystaline effects and micro-diodes. This one is nuts. Somewhere in the mists of time there was some research that found that at cryogenic temperatures and under certain conditions there were semiconductor effects just visible between crystal interfaces in certain alloys. This got seized upon and turned into an important issue for audio cables. These "micro diodes" would cause tiny rectification artefacts and distort the sound. So you get "linear crystal" and "continuous cast" wire and suchlike. Also nuts. But sells well. Pure snake oil.

Non metal cables. Cables that are made of carbon fibre, and somehow avoid the "damaging effects" of being made of metal. WTF?? Meaningless drivel.

But there are interesting issues.

Cable insulation. This could have an effect. Just like capacitor dielectric issues, the material used can have subtle effects on the signal. The RF guys have to worry about losses in the dielectric, and the underlying cause of some of these losses could manifest themselves at audio frequencies. I do worry about residual charge effects. Where a dielectric essentially has a small memory (a hysteresis). In a high impedance circuit especially, this could lead to a subtle intermodulation distortion mechanism. Insulation like foamed Teflon is very good, as in polypropylene.

Triboelectric effects. Microphone cables are designed for low handling noise, which includes choice of insulating materials that have no triboelectric effect. But fixed cabling subject to vibration can see induced voltages. Perhaps even your monitoring speakers can cause problems. These would be signal correlated effects, so bad. Sadly Teflon is not so good here.

Shielding. Pro audio is mostly balanced, and with good reason. The idea that a balanced line is immune from common mode noise, and that differential is very hard to pick up. However common mode noise rejection is typically measures as a separate artefact from distortion. I do worry about the possibility of common mode noise to signal intermodulation distortion. I suspect that some receiver circuits are a lot less immune than others. So whilst they may sound quiet, and measure well, they may not have good performance in the face of lot of common mode noise. Thus the quality of the cable construction, and in particular its intrinsic ability to not pick noise up will matter. Shielding quality basically.

Anyway, there are a few issues. There are more. Both more possibly important ones and a heap more totally fallacious ones.

[nosebleedaudio]

I will add that the mic see's the impedance of the cable more than anything else.
Have seen many times where LONG runs produce a VERY noticeable difference.
And if anyone thinks all cables are the same, well, it would not make any difference to me and a boatload of top engineers.
And it does not have to be that $50.00 a foot stuff either.
Mogami 2549 has about the lowest capacitance of any cable I've seen...

[Blast9]

Mike,

Can you confirm that you mean impedance of the cable and not capacitance?

And (anyone) --- With respect to cables: Is impedance relative to the relationship between the input device, the cable and the receiving device, (i.e. the whole circuit) or does each individual component "have an impedance" ?

[nosebleedaudio]

Originally Posted by Blast9

Mike,

Can you confirm that you mean impedance of the cable and not capacitance?

And (anyone) --- With respect to cables: Is impedance relative to the relationship between the input device, the cable and the receiving device, (i.e. the whole circuit) or does each individual component "have an impedance" ?

Yes I was referring to the capacitance of the cable, that's what adds up with the length. And more specifically the capacitance between the 2 conductors, pin 2 and 3.

[tINY]

Cable does have a chariteristic impedance defined by the inductance and capacitance of the "transmission line".

Resistance is just a transmission loss.

But, impedance isn't important for audio cables shorter than several miles.




-tINY

[nosebleedaudio]

Originally Posted by tINY

Cable does have a chariteristic impedance defined by the inductance and capacitance of the "transmission line".

Resistance is just a transmission loss.

But, impedance isn't important for audio cables shorter than several miles.




-tINY

Right, and the characteristic impedance does NOT change with length...

[DamnYankee]

Please understand I do not doubt his credentials. I have had enough electricity in my undergrad studies so I have a fair grasp of it. Here's how I understand it:

Resistance opposes current.

Cables really don't carry much current (I or amperage "amps") at all but they do carry voltage (E); and a side note, this is where capacitance comes into play.

As cables don't have much current (I) but carry voltage (E), the above equation tells you resistance (R) has to be negligable. Here's what I mean:

Take copper wire. Current carrying capacity of copper wire will double or cut in half with every 3 AWG change. A 10 AWG wire has a max carrying capacity of 30 amps. 13 AWG has a max carrying capacity of 15 amps (house wiring is usually 12 or 14 AWG - which is why you have 15 amp circuit breakers). Likewise, 16 AWG -> 7.5 amps, 19 AWG -> 3.75 amps, 22 AWG -> 1.875 amps, 25 AWG -> .9375 amps.

Instrument wire used in line levels can carry over 10+ volts! So let's say we have a 25 AWG line level cable (crappy Hosa) and our cable is pushing 11 volts (which I hope most of us would agree is an extreme condition for this AWG cable). let's calculate the max resistance:

E = I x R or rearranging:
R = E/I
R = 11/.9375
R = 11.7 ohms

11.7 ohms of resistance is so infintesimally small, it's impossible your ear can even perceive it.

In regards to your ribbon mic (I assume it's an older ribbon mic and not the new fancy ones with a step up transformer that can have outputs higher than dynamic mics): it has a very low voltage output to begin with - like, below 1 volt - and the low voltage output - NOT THE RESISTANCE - is why you need to crank up your mic pre gain.

So you get the full picture, you should note your electric geetar only outputs a few milliVolts and that signal is able to carry across a similar gauge instrument cable 20' to 25' feet to your favorite geetar amplifier...so again, resistance is not really a factor (until you get to longer cable lengths where the voltage isn't strong enough to push your lovely audio electrons thru the copper wire).

Quiz over this material will be on Friday. Class dismissed.

Originally Posted by Drumminkiger

I dont think his information is entirely incorrect, he has a BA in electronics engineering on top of being a great seasoned audio engineer (We called him grandpa at school because he's been in the bizz since 1974). My main point with all of it was, say you have a low level source like a ribbon mic and then you run that signal through a cable with higher resistance, you're alredy low level signal will come through that cable into your mic pre at an even lower level (meaning less volume getting to your mic pre). Then you have to crank up your mic pre higher to get the same level into your recorer. Is that a sonic differance? I suppose that is open to inturpritation, but to me it is because it means you have to add more gain and it will amplify any other noise that that cable is picking up along the way as well as your source. I would imagine that with a line level source like an RF signal this would be less of a factor because you're not gaining it up as much on the other end correct? Cheap cableing is a plauge to any studio, and my main point to all of this was that for the same money as hosa, you can have high quality cables to interface your gear that will last a long time, and deliver you good signal. I highly doubt any claim that a cable built with poor components is equal in quality to a cable built with premium components. Maybe intially there will be very little differance, but with some use that will become much greater as my experiance (and im sure many other engineers who have used bargin brand cables) has proven to me.

[Francis Vaughan]

Sort of. A few problems however.

Resistance doesn't really oppose current. In a loose sense it does, but if you get into the nitty gritty the idea starts to break down. Oppose implies something more active.

The usual way of explaining resistance is with fluid flow. You have water flowing though a pipe. The rate of water passing past a given point is the same as current. Literally the number of electrons passing a point in your wire. However in order to make water flow in a pipe you need pressure. Pressure is like voltage. All pipes have some friction, and if you apply pressure you only get a certain rate of flow. This friction is resistance. Get a bigger pipe and for the same pressure more water flows. Get a thinner pipe and less water flows. Real hydraulic systems are messy to analyse unless they exhibit laminar flow, but electrical systems are extraordinarily linear until you get to insanely fringe conditions. So you get Ohm's law.

When working with wire you need to work out the resistance based upon the specific resistivity of the material. For copper at room temperature this is 17.2 nano-ohm metres. (The resistance you see across two opposite sides of a one metre cube of copper.) 24 AWG copper has a resistance of 0.0303 Ohms per foot. 19 feet for an Ohm.

If you want to work out what the signal loss is due to the wire resistance you simply need to work out the equivalent potential divider that exists.

The case in point. Lets say we have a ribbon mic, with an impedance of 0.5 Ohms. 20 feet of 24AWG balanced cable, and a mic pre with an input impedance of 1k Ohm. The voltage that the mic pre sees, and will amplify, appears across the 1k Ohm input impedance. The loss due to the cable resistance is almost exactly 1/500th of the voltage generated by the mic. If the input impedance of the pre was higher, and a lot are, then the loss would be even less.

If the mic pre was a current input device, which might be an interesting idea for a ribbon, it would have an input impedance of as close to zero as we could manage. Then the cable would matter a lot. But such a pre would be best built into the mic anyway.