A few weeks ago i did a bit of experimentation with some screened speaker cable in one of my systems , most noticable differences i've ever experienced from a cable .
Completely killed the dynamics and reduced the treble so much i thought i'd blown the tweeters at first !
What do you call "very long"?
10 meters away is a distance easy to reach even in a regular home living room, spacially because wires are not used line of sight amp to speaker but along walls, behind furniture, maybe around a door or window frame.
And effective distance is twice that, because you have send and return paths.
So in a 10 meter cable you have 20 meters, meaning 0.42 ohms.
That alone will have a significant, audible effect on speaker response.
Of course, if speakers are within 1 or 2 meters each side of the amplifier, practically "anything" will do.
Thinner wires have more inductance, less capacitance.SpartanX58 said:
Skin effect has almost no effect at audio frequencies. If your cables are so long that skin effect is relevant then they are so long that much bigger effects are also relevant. Don't worry about skin effect.
For speaker cables about the only thing which matters is resistance, so use thick cables. For interconnects the resistance does not matter at all, so use flexible cables.
A simple flat resistive potential divider does not affect sound quality. A speaker has impedance which varies with frequency in a quite lumpy way so it needs low impedance cables.
No damage to the valve amp. Just some damage to sound quality, if the amp is poorly designed and so has a high output impedance.
You seem to have been reading too many audiophile scare stories.
Extra capacitance can push some amplifiers towards HF instability. This will usually not itself be audible as it will be at too high a frequency, but its effects may be. There is no need for screened speaker cables.Konzentr8 said:
DF
When cable length gets longer than 75M around here it RF pickup can be an issue. So my current magic cable does use a shield (screen.)
As many of the loudspeakers used for very large venues are multiway it becomes reasonable to use a thinner cable for the HF section. For some funny reason even at lengths above 300M I have yet to observe limits due to inductance of the cable.
Just for clarity wire is a single conductor. Cable contains multiple wires in a common jacket. A bundle of wires is not quite a cable.
My typical multiconductor cable costs more than a dollar a foot in small truckload quantities.
Now for personal use on very short runs <5M 18 gauge may not be unreasonable. But the thinnest I ever use is 16 gauge. Electrical codes step in if you go thicker than 10 gauge. The code assumption is you must be handling potentially harmful amounts of power with the thicker cable. The other limit is the Neutrik loudspeaker connectors really max out at 11 gauge.
When cable length gets longer than 75M around here it RF pickup can be an issue. So my current magic cable does use a shield (screen.)
As many of the loudspeakers used for very large venues are multiway it becomes reasonable to use a thinner cable for the HF section. For some funny reason even at lengths above 300M I have yet to observe limits due to inductance of the cable.
Just for clarity wire is a single conductor. Cable contains multiple wires in a common jacket. A bundle of wires is not quite a cable.
My typical multiconductor cable costs more than a dollar a foot in small truckload quantities.
Now for personal use on very short runs <5M 18 gauge may not be unreasonable. But the thinnest I ever use is 16 gauge. Electrical codes step in if you go thicker than 10 gauge. The code assumption is you must be handling potentially harmful amounts of power with the thicker cable. The other limit is the Neutrik loudspeaker connectors really max out at 11 gauge.
for a 5m run of 0.021ohms/meter cable, the cable adds 0.21ohms to the speaker's source impedance.
That will have an effect on the Q of the speaker.
Typically an amplifier has an output impedance of 10milli-ohms to 50milli-ohms.
Most speakers are designed to suit that plus a nominal amount of cable resistance.
Adding an extra 200milli-ohms is unlikely to have been allowed for by the speaker designer, unless they specifically mention that their particular speaker NEEDS a high source impedance for best "in-room" performance.
Posts 15, 16 & 20 start to address this.
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As a PA operator, I would never ever use screened speaker cables. The losses are far too great.
Using my 6kW Nexo System, Tops, Mid, Bass and Subs, always use 8 core 8mm cable, (yes it is a challenge to fit it in and wire it to the 8pole Speakon plugs), up to 30feet away otherwise put the power amps on stage next to the speakers. If you use 4mm cables, bass and treble, the bits that need the most power, become lacking due to losses in the cable.
Skin effect is for RF signal, VHF and up. That is why we use silver plated copper cables to feed aerials and baluns.
It is of no advantage in audio gear as not only does the audio use the whole area of the conductor, silver is not as good a conductor of electricity as copper.
Totally different scenario, from home use.
Using my 6kW Nexo System, Tops, Mid, Bass and Subs, always use 8 core 8mm cable, (yes it is a challenge to fit it in and wire it to the 8pole Speakon plugs), up to 30feet away otherwise put the power amps on stage next to the speakers. If you use 4mm cables, bass and treble, the bits that need the most power, become lacking due to losses in the cable.
Skin effect is for RF signal, VHF and up. That is why we use silver plated copper cables to feed aerials and baluns.
It is of no advantage in audio gear as not only does the audio use the whole area of the conductor, silver is not as good a conductor of electricity as copper.
Totally different scenario, from home use.
Skin effect takes place at audio frequencies. You can calculate it, and if careful measure it.
Skin effect has negligible effect at audio frequencies. As I said, if your wiring is such that skin effect is noticeable then much bigger effects will already be noticeable too.
Silver plating is used for VHF etc. because silver is a slightly better conductor than copper.
Skin effect has negligible effect at audio frequencies. As I said, if your wiring is such that skin effect is noticeable then much bigger effects will already be noticeable too.
Silver plating is used for VHF etc. because silver is a slightly better conductor than copper.
My apologies, I keep getting Gold and Silver mixed up. Only been almost 70years. Doh!
Not by much.
Resistivity of metals normalized to copper (100%):
Silver 106%
Gold 76%
Platinum 16%
2% silver solder 12.3%
tin lead 11.9%
Other than silver it was all a bit of a surprise to me. I thought gold was just marginally worse than copper and platinum only being about the same as solder was also unexpected.
Resistivity of metals normalized to copper (100%):
Silver 106%
Gold 76%
Platinum 16%
2% silver solder 12.3%
tin lead 11.9%
Other than silver it was all a bit of a surprise to me. I thought gold was just marginally worse than copper and platinum only being about the same as solder was also unexpected.
Certain grades of copper (11xx series) can exceed the IAC reference standard (where IACS = 100) to 101% or even slightly higher (< 102%). Not much, but there you go. Brass varies considerably, but 40~60% IACS is quite common for electronics grades.
Silver is used as an over-plating to copper to eliminate corrosion, typically in military, aircraft, and aerospace applications, (where it often, but not always, is used to carry DC, not AC). When Silver is used to take on the entire Skin Effect at Very High Frequencies, it's usually over-plated on steel, which is much cheaper than copper, and as an added bonus, stronger.
Silver is used as an over-plating to copper to eliminate corrosion, typically in military, aircraft, and aerospace applications, (where it often, but not always, is used to carry DC, not AC). When Silver is used to take on the entire Skin Effect at Very High Frequencies, it's usually over-plated on steel, which is much cheaper than copper, and as an added bonus, stronger.
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Hello,
Given that the conductivity of solders:
2% silver solder 12.3%
tin lead 11.9%
All the more reason to not worry about the solder type, but make sure there is a good mechanical connection before applying solder to a connection. In other words - Good contact between wire and contact surface before soldering is the key to a good electrical connection. Not magical solder.
Regards,
Greg
Given that the conductivity of solders:
2% silver solder 12.3%
tin lead 11.9%
All the more reason to not worry about the solder type, but make sure there is a good mechanical connection before applying solder to a connection. In other words - Good contact between wire and contact surface before soldering is the key to a good electrical connection. Not magical solder.
Regards,
Greg
Yeah, but "magical solder" sounds better!!!:
"Voices were improved in diction and feeling; music took on an accuracy and beauty previously unheard. The upper runs were phenomenally clear and meaningful, providing a stronger foundation for the music. Variations in volume were handled in a manner which allowed more insight and emotional content to the music. This provided an unsurpassed clarity and detail unlike any heard before."
Regarding: "Yeah, but "magical solder" sounds better!!!:
"Voices were improved in diction and feeling; music took on an accuracy and beauty previously unheard. The upper runs were phenomenally clear and meaningful, providing a stronger foundation for the music. Variations in volume were handled in a manner which allowed more insight and emotional content to the music. This provided an unsurpassed clarity and detail unlike any heard before."
Perhaps, but getting high or closing your eyes to listen is so much cheaper and does the same thing.
"Voices were improved in diction and feeling; music took on an accuracy and beauty previously unheard. The upper runs were phenomenally clear and meaningful, providing a stronger foundation for the music. Variations in volume were handled in a manner which allowed more insight and emotional content to the music. This provided an unsurpassed clarity and detail unlike any heard before."
Perhaps, but getting high or closing your eyes to listen is so much cheaper and does the same thing.
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