AuroraB said:
I'm not going to argue about this other than my speakers
are nominally 8 ohm and are pretty near over most of the range.
I'm not suggesting transmission line impedance matching occurs
or that if it does at some points that it is audibly significant.
But I do believe the combination of inductance and capacitance
you get is equivalent to many so-called 8 ohm cables, unless
I have misunderstood something.
And I believe you need a 2:1 balun transformer to efficiently split
a cable, e.g. 50ohm in to 2 x 50ohm out, which suggests without
the balun you would get a 50 ohm to 25 ohm mismatch.
So I believe the CAT5 cable as described is 8.3 ohm overall,
though of course each pair is still 100ohm, 12 of in ||.
🙂 sreten.
Good reading for those who believe a CAT5 has 100 ohm characteristic impedance at audio frequencies:
http://home.mira.net/~marcop/ciocahalf.htm
A twisted pair used in landline phone systems are around 100 ohm at high frequencies but 600 ohm at 1 kHz. Do anyone recognize those figures? 😉
http://home.mira.net/~marcop/ciocahalf.htm
A twisted pair used in landline phone systems are around 100 ohm at high frequencies but 600 ohm at 1 kHz. Do anyone recognize those figures? 😉
Jax said:
I'm only claiming that the CAT5 cable as described has
characteristics similar to other so-called 8 ohm loudspeaker
cables.
I'm not claiming it is an 8 ohm cable, its part of the so-called group.
🙂 sreten.
Characteristic impedance is rather meaningless at these electrical wavelength. OTOH, inductance, resistance, and capacitance can and often do have audible and measurable consequences, especially with speakers that have large impedance swings and amps with high source Z and/or marginal stability.
That doesn't mean that multi-kilobuck cables aren't a total rip (they are), it means that changing cables can and often does lead to real differences, ones that are totally non-mysterious. And understanding that, diyers have a good shot at making something satisfying without having to learn about retarded potentials and scalar gauges.
The work by Davis and Greiner is quite significant.
That doesn't mean that multi-kilobuck cables aren't a total rip (they are), it means that changing cables can and often does lead to real differences, ones that are totally non-mysterious. And understanding that, diyers have a good shot at making something satisfying without having to learn about retarded potentials and scalar gauges.
The work by Davis and Greiner is quite significant.
If we build an amplifier, we can do so with an almost infinite variety of components from the bog standard to the so-called audiophile quality (no I'm not starting that argument here).
We can also build different styles of case to house this amplifier. And if we do, we find that the style, material, weight, density of the case makes as much, if not more difference to the sound quality as swapping components.
Now, for a speaker cable (or any other connecting device) we need a conductor. The insulation is not required for the purpose of signal transfer and is included only for reasons of practicality.
Whats my point? I see counlless arguments about cables, their L,C and R but hardly ever is any consideration given to the insulation other than its dielctric value which is an insignificant factor compared to its mass.
Sure, CAT 5 has a good quality copper conductor but it sounds good because its insulation is low mass.
Remember, we are not trying (or shouldn't be) to dampen the signal to the speaker but that's what the cable insulation is doing, and the more insualtion, the more damping. And if you have a good enough system/ears, you should be able to hear the difference between CAT5 and a much thicker cable.
Ironically, when people realised that you could actually get others to hand over large amounts of money for 'audiophile' cables, they
began a race to see who could make the biggest, most expensive looking examples and sound quality actually suffered as a consequence.
I'm not saying it will work in all systems, but a single pair of solid core CAT 5 works very well for me.
We can also build different styles of case to house this amplifier. And if we do, we find that the style, material, weight, density of the case makes as much, if not more difference to the sound quality as swapping components.
Now, for a speaker cable (or any other connecting device) we need a conductor. The insulation is not required for the purpose of signal transfer and is included only for reasons of practicality.
Whats my point? I see counlless arguments about cables, their L,C and R but hardly ever is any consideration given to the insulation other than its dielctric value which is an insignificant factor compared to its mass.
Sure, CAT 5 has a good quality copper conductor but it sounds good because its insulation is low mass.
Remember, we are not trying (or shouldn't be) to dampen the signal to the speaker but that's what the cable insulation is doing, and the more insualtion, the more damping. And if you have a good enough system/ears, you should be able to hear the difference between CAT5 and a much thicker cable.
Ironically, when people realised that you could actually get others to hand over large amounts of money for 'audiophile' cables, they
began a race to see who could make the biggest, most expensive looking examples and sound quality actually suffered as a consequence.
I'm not saying it will work in all systems, but a single pair of solid core CAT 5 works very well for me.
SY said:
Using ribbon cable, you have to be careful about the final geometry of the ribbon...if you keep it flat, the center runs will be excluded from conduction as the frequency goes up.
For my mobile apps, I use 12/3. It was available at Sams Club for 17 USD per 90 feet (I think 90 feet was a production error, that's why the cheap price). It was available in neon colors, green, yellow, orange, and bright purple..So I color coded by length with 2 90's, 2 45's, and a whole mess of 20's and 10's.
As I'm using Neutrik 4 pin connectors, I ran 1+ black..1- white, and 2+ green.. that way, the cables are suitable for either straight connections, or for bridged apps.
Cheers, John
jneutron said:
Not if you wire it as go/return/go/return etc: Each wire will then only see the influence of its neighbour.
(And it keeps the inductance really low)
Bill Fitzpatrick said:
Hey, it's not my fault you have a dial-up connection. You asked for it, so I gave it to you. Deal with it!
BTW, I don't know what's wrong with your computer, but my Linux site comes up just fine on all the computers and locations I've tried, even on our dial-up at work.
Re: Re: building speaker cable
The cross connect coax you mention...ala J Risch..reduces inductance, but increases capacitance..using the Belden 89259 as he recommends results in an inductance per foot of about 65.75 nanohenries by calcs, 67 by measurement, with a capacitance of about 35 pf per foot, with a resistance per foot of 2.21 milliohms per foot.
The coax nominal inductance is 92 nH per foot, but when cross connected, the inductance lowers because of opposite direction current neutralizing part of the external inductance field.
Unfortunately, since the shield is 2.6 mOhms per foot, with the center conductor 15 mOhms, the center conductor carries only 14.77% of the total current, so the neutralization is incomplete.
If one can find a coax cable with the same inner and outer resistance, the cross connect coax can fully neutralize the external inductance. The resistive imbalance means the cable wil still be susceptible to pair spacing issues, with the external dipole field..
The wire I'm working on so far has a measured inductance of 29 nanohenries per foot..the final one I believe will go below 20 nH per foot.
Cheers, John
sreten said:
The cross connect coax you mention...ala J Risch..reduces inductance, but increases capacitance..using the Belden 89259 as he recommends results in an inductance per foot of about 65.75 nanohenries by calcs, 67 by measurement, with a capacitance of about 35 pf per foot, with a resistance per foot of 2.21 milliohms per foot.
The coax nominal inductance is 92 nH per foot, but when cross connected, the inductance lowers because of opposite direction current neutralizing part of the external inductance field.
Unfortunately, since the shield is 2.6 mOhms per foot, with the center conductor 15 mOhms, the center conductor carries only 14.77% of the total current, so the neutralization is incomplete.
If one can find a coax cable with the same inner and outer resistance, the cross connect coax can fully neutralize the external inductance. The resistive imbalance means the cable wil still be susceptible to pair spacing issues, with the external dipole field..
The wire I'm working on so far has a measured inductance of 29 nanohenries per foot..the final one I believe will go below 20 nH per foot.
Cheers, John
Ouroboros said:
If you keep it flat, the outer two wires run in an asymmetric field. As the frequency increases, that asymmetry will begin to propagate inward, affecting the entire ribbon eventually..
Without modelling or testing it, I have no idea what frequency normal conductors will start that effect..I've only superconductor experience to base it on, and they are a bit on the extreme side. But, the effects I see with supers are mirrored by what happens with normal materials, just shifted a bit.
But you are right..the main pack inductance will be in the mud..
"Not if you wire it as go/return/go/return etc: Each wire will then only see the influence of its neighbour.
(And it keeps the inductance really low)"
... and the capacitance really high!
(And it keeps the inductance really low)"
... and the capacitance really high!
oops...
For a ribbon wired +/-/+/-.....as the frequency goes up, I believe the outers will decouple first, not the inners as I incorrectly stated..
Cheers, John
For a ribbon wired +/-/+/-.....as the frequency goes up, I believe the outers will decouple first, not the inners as I incorrectly stated..
Cheers, John
What would happen if we rolled the ribbon cable? Wouldn't that reduce the decoupling of the outer conductors?
"Gentlemen please, There’s no fighting in here, this is the war room!"
Joe04,
Remember, Have Fun.
So, your probably wondering by now what you’ve gotten yourself into. You’ve stepped knee deep into one of this communities oldest and most controversial subjects. (Only topped by the proper temperature to serve a Guinness at. The answer is linked to Lucas refrigeration)
My advice still stands. Try everything that doesn’t cost you too much money. Listen carefully and think about why you may or may not be getting the results you want. Have fun. And don’t forget to try the Zip Cord.
-Dave
Joe04,
Remember, Have Fun.
So, your probably wondering by now what you’ve gotten yourself into. You’ve stepped knee deep into one of this communities oldest and most controversial subjects. (Only topped by the proper temperature to serve a Guinness at. The answer is linked to Lucas refrigeration)
My advice still stands. Try everything that doesn’t cost you too much money. Listen carefully and think about why you may or may not be getting the results you want. Have fun. And don’t forget to try the Zip Cord.
-Dave
Attachments
Chops
Why the packing material taped around the bottom of your TV stand? Is there something secret in there that you cant share with us, is it for acoustic purposes, or is it just to keep your little black cat from chewing on your interconnects.
-Dave
Why the packing material taped around the bottom of your TV stand? Is there something secret in there that you cant share with us, is it for acoustic purposes, or is it just to keep your little black cat from chewing on your interconnects.
-Dave
Jax said:
Yep..specially if you made it entirely symmetrical, so that every wire sees the exact same thing.
John
Flat stuff
This stuff is made so you can stick it to a wall and paint over it (has an adhesive side), but its pretty good stuff and not all that expensive.
http://www.partsexpress.com/pe/show...38&St3=44304788&DS_ID=3&Product_ID=2753&DID=7
I personally have used this, kimber 8pr, and the cat5 plenum 15-braid formula, and I favor the kimber and yes I can hear a difference. Luckily I got a great deal on the kimber (free) so for me it was my cheapest one too!
This stuff is made so you can stick it to a wall and paint over it (has an adhesive side), but its pretty good stuff and not all that expensive.
http://www.partsexpress.com/pe/show...38&St3=44304788&DS_ID=3&Product_ID=2753&DID=7
I personally have used this, kimber 8pr, and the cat5 plenum 15-braid formula, and I favor the kimber and yes I can hear a difference. Luckily I got a great deal on the kimber (free) so for me it was my cheapest one too!
Da5id4Vz said:
It's because of one of my other little black cats. Now since he's 18+ years old, his mind isn't all there anymore and he likes to go back there and sleep, which in turn he is unplugging ICs and power cables from laying on top of them. 😉
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