Basic speaker cable question

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Both wires take same current so need to be same gauge.
If you want an improvement use thicker wires and/or shorter wires.
Shorter or thicker wires (of same material) improve impedance losses.

Are you referring to the unbalanced interconnects I was asking about or the speaker cables the OP was referring to?

If the unbalanced interconnects, then having the same gauge central conductor as the shield would be difficult and certainly not similar in geometry.
 
Perhaps if you sink a ground rod at each speaker and one at the amp, you might have a point. But a very important aspect of low impedance connections is the inductance that results from the loop area between conductors, which is why even power lines alternate positions. "Ground" voltage does not magically go to zero. It's more like the water level on the ocean. If you pour current into "ground", the level rises around that point. The exact ground voltage is different than it is a few inches away so you see PCB ground traces running in parallel, not connecting together until they reach a single point ground. It's call avoiding a "ground loop". You may also want to study transmission line theory.

Most expensive speaker wire is bad science, which focuses on DC resistance when what is more important is the transmission line impedance. Marketing is about finding what people think is cool without talking over their head. A good compromise is 4-16 to 4-12 cable with opposite conductors wired together in an X pattern. This cancels most of the inductance.
 
Last edited:

PRR

Member
Joined 2003
Paid Member
Perhaps if you sink a ground rod at each speaker and one at the amp, you might have a point. But a very important aspect of low impedance connections is the inductance that results from the loop area between conductors....

A "ground rod" rarely has less than 50 Ohms resistance.

So going out on the lawn with an 8 Ohm speaker and two dirt-rods will be "a clue": 90% of your power lost in a poor return connection.

Much more than is lost (in audio) by loop inductance. (In my long power line, inductance of twisted-trio cable is a minor correction; even at higher supply frequency or with a typical space-pair it is overwhelmed by simple resistance loss in the metal.)
 
steveu said:
Most expensive speaker wire is bad science, which focuses on DC resistance when what is more important is the transmission line impedance.
No. Concentrating on DC resistance (up to a point) is the right thing to do. Inductance is far less important, unless some unusual cable construction is used which artifically increases inductance beyond normal levels. This is sometimes found in daft DIY cables or expensive 'highend' cables.

Transmission line characteristic impedance for a speaker cable is almost irrelevant. In the audio frequency region it is non-resistive and varies with frequency, so you can't match it even if you wanted to. There may be some small benefit for amplifier stability and RF pickup if you achieve a rough match at RF by adding a Zobel network at the far end, but this is not critical and most setups work fine without it.
 
diyAudio Member
Joined 2007
Reminds me of a post here years ago, by a respected speaker builder, recommended using a bigger return wire than input wire as far as DC resistance went and for years I have been making up speaker cable with cheap 3-core flex, using the brown P+ wire for the speaker in and the coupled Blue and Green for the N- return. They didn't sound any better but I saved a lot of money as people are always throwing away vacuum cleaners with very long leads attached ready for salvage, sometimes 2-core but often 3-Core
 
Perhaps if you sink a ground rod at each speaker and one at the amp, you might have a point. But a very important aspect of low impedance connections is the inductance that results from the loop area between conductors, which is why even power lines alternate positions. "Ground" voltage does not magically go to zero. It's more like the water level on the ocean. If you pour current into "ground", the level rises around that point. The exact ground voltage is different than it is a few inches away so you see PCB ground traces running in parallel, not connecting together until they reach a single point ground. It's call avoiding a "ground loop". You may also want to study transmission line theory.

..............................................
If "ground" in this case is Planet Earth, then current never goes to "ground". While it may travel thru "ground", it always goes back to it's power source.

Note that Planet Earth will never act as a sink or sump for bad electricity.
 
If "ground" in this case is Planet Earth, then current never goes to "ground". While it may travel thru "ground", it always goes back to it's power source.

Note that Planet Earth will never act as a sink or sump for bad electricity.

Humm, I'm not sure about that ....
Have you tried switching on a common resistive filament lamp with one cable in the socket and the other one grounded? The potential difference causes it to turn on, a current will circulate because the electric generator of the light power plants are connected to ground, and it acts as a conductor.

It is common to confuse the neutral and live of the outlets (alternating current) as if they were negative and positive from a direct current source. The current that circulates through the audio cables is alternating, if DC current circulates, the amplifier and / or the speakers pass to a better life.
 
Last edited:
This is great, I much prefer science than alchemy, this is why I came here to ask this question. I want to thanks every responders and I hope others will find this thread helpful too. I think I will enjoy my current set-up since it already sounds amazing and stop thinking “what if cables would make it 1% better”. Right now I’m using Ethernet wire cables, hard colour together and dash colour together. I can’t hear a difference using 2 cables or 1 cable so I stick to 1.
 

PRR

Member
Joined 2003
Paid Member
....Have you tried switching on a common resistive filament lamp with one cable in the socket and the other one grounded? ....

You mean, to a dirt-rod?

I have. The bulb is dim.

This with a nominal 120V 0.5A (60W) lamp and 7 feet of rod under my septic field; and the power company dirt-rod (2 8') on the far side of the field.

My summary data suggests around 120 Ohms from a full size dirt-rod to another rod on the same land, implying 60 Ohms from one rod to an imaginary "true earth".

My 60W lamp is nominally 120V/0.5A= 240 Ohms, so 60-120 Ohms in series makes it dim. (And a dim bulb is a lower resistance, so I was getting like half of line voltage.)

This incidentally means I can NOT blow a breaker with "earth current" literally through dirt. Three 60 Ohm rods is 20 Ohms, marginally under the NEC goal of 25 Ohms, but 120V/20r is only 5 Amps, and my smallest breakers are 15A.

Things CAN be different on the damp salty coast of Florida.
 
Last edited:
academia50 said:
Humm, I'm not sure about that ....
Have you tried switching on a common resistive filament lamp with one cable in the socket and the other one grounded? The potential difference causes it to turn on, a current will circulate because the electric generator of the light power plants are connected to ground, and it acts as a conductor.
You are agreeing with him. He said currents never go 'to ground', but can travel 'through ground'.

kodabmx said:
Excepting radio? :p
Sometimes radio uses ground as the other half of an antenna. This is because an antenna made of a conductor must have two terminals, but in some cases the second terminal can be hard to spot - which leads some people to claim that some antennas only have one terminal. Ground does not make a good half-antenna, but sometimes it is all we have. Even when used for radio, ground is not a magic sink for unwanted currents.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.