Scifi
Super Member
People have debated whether or not speaker cable or other cables or wires have an effect on the sound. I found some patents that discuss the quality of copper and silver that look interesting.
http://www.google.com/?tbm=pts&hl=en
US 4874436 Method for producing high purity electrolytic copper
US 4964738 Electrical conductor of high magnetic permeability material for audio
circuits
preamp -> amp
column 3 lines 66+
Unfortunately, the only metal with higher electrical conductivity than copper is silver, and the improvement in skin depth is only approximately 3 percent--a negligible improvement at great cost.
US 5099518 Electrical conductor of high magnetic permeability material for audio circuits
US 5510578 Audio loudspeaker cable assembly
copper and/or silver column 3 lines 2-3
US 5523528 Interconnection cable for low frequency signal transmission
The inner conductors insulated from each other are shielded by a shielding layer made of copper fabric woven of high-purity copper wires or silver plated copper wires (column 1 lines 50-51)
US 5900589 Silver ribbon cable
US 6231637 Process for producing high-purity silver materials
column 1 lines 19-32
With copper wires having purities on the order of 99.9 wt %, signals cannot be transmitted correctly without phase differences and, as a result, only blurred images or unsharp sounds are produced. To solve these problems, high-purity copper wires produced by working raw materials having purities of at least 99.999 wt % have recently been introduced into the market.Similar effects are exhibited by silver wires that are produced by a process which comprises solidifying silver with a purity of at least 99.95 wt % in one longitudinal direction to yield an ingot, drawing it by either cold or warm working and further working the wire under conditions that will not cause recrystallization.
US 4582545 Method of producing electrical conductor
column 1 lines 10+
As is well known, an electrical conductor is generally made of one of two types of copper: tough pitch copper (TPC) and oxygen-free copper (OFC) The copper is generally worked so as to be circular or rectangular in cross section or in the form of a foil and then recrystallized by annealing at a temperature ranging between 300.degree. and 600.degree. C. to produce the conductor.It has recently been understood that an electrical conductor made of OFC in a transmisison line for a multi-frequency audio signal, particularly, as an inner wiring conductor or a loud speaker wiring conductor of an audio apparatus, is much superior to one made of TPC.
US 5574260 Composite conductor having improved high frequency signal transmission characteristics
Use of silver plating
http://www.google.com/?tbm=pts&hl=en
US 4874436 Method for producing high purity electrolytic copper
US 4964738 Electrical conductor of high magnetic permeability material for audio
circuits
preamp -> amp
column 3 lines 66+
Unfortunately, the only metal with higher electrical conductivity than copper is silver, and the improvement in skin depth is only approximately 3 percent--a negligible improvement at great cost.
US 5099518 Electrical conductor of high magnetic permeability material for audio circuits
US 5510578 Audio loudspeaker cable assembly
copper and/or silver column 3 lines 2-3
US 5523528 Interconnection cable for low frequency signal transmission
The inner conductors insulated from each other are shielded by a shielding layer made of copper fabric woven of high-purity copper wires or silver plated copper wires (column 1 lines 50-51)
US 5900589 Silver ribbon cable
US 6231637 Process for producing high-purity silver materials
column 1 lines 19-32
With copper wires having purities on the order of 99.9 wt %, signals cannot be transmitted correctly without phase differences and, as a result, only blurred images or unsharp sounds are produced. To solve these problems, high-purity copper wires produced by working raw materials having purities of at least 99.999 wt % have recently been introduced into the market.Similar effects are exhibited by silver wires that are produced by a process which comprises solidifying silver with a purity of at least 99.95 wt % in one longitudinal direction to yield an ingot, drawing it by either cold or warm working and further working the wire under conditions that will not cause recrystallization.
US 4582545 Method of producing electrical conductor
column 1 lines 10+
As is well known, an electrical conductor is generally made of one of two types of copper: tough pitch copper (TPC) and oxygen-free copper (OFC) The copper is generally worked so as to be circular or rectangular in cross section or in the form of a foil and then recrystallized by annealing at a temperature ranging between 300.degree. and 600.degree. C. to produce the conductor.It has recently been understood that an electrical conductor made of OFC in a transmisison line for a multi-frequency audio signal, particularly, as an inner wiring conductor or a loud speaker wiring conductor of an audio apparatus, is much superior to one made of TPC.
US 5574260 Composite conductor having improved high frequency signal transmission characteristics
Use of silver plating