RCA connectors react to magnets...is that bad or doesn't matter? What does science say about this?

[GabrielPhoto]

Hi!
I was buying a couple of short RCAs and got curious when I read some reviews pointing out how the connectors were attracted to magnets.
Like this:

Check out this Amazon review of CESS-163-4i Low Noise 12 Gauge Premium RCA Audio Line Patch Cable (4 Inches)

Cheap metals!

www.amazon.com

Or this comment:
The cables are VERY WELL MADE *BUT* they used steel in the connectors that will absolutely result in buzzing, hum and noise. Steel develops a Search term:magnetic field when current passes through it, then when the current drops, the Search term:magnetic field collapses and dumps that energy into the conductor as electricity. This equals noise in an audio application.

 

[Speedskater]

Well some audiophiles use the coax cable that the cable TV installer has on his truck. They use it for audio interconnects. This coax has a Copper Clad Steel (CCS) central conductor. We don't hear reports about how bad this cable sounds.

 

[GabrielPhoto]

Well some audiophiles use the coax cable that the cable TV installer has on his truck. They use it for audio interconnects. This coax has a Copper Clad Steel (CCS) central conductor. We don't hear reports about how bad this cable sounds.

I guess their superhuman senses are picky?

 

[DVDdoug]

Or this comment:
The cables are VERY WELL MADE *BUT* they used steel in the connectors that will absolutely result in buzzing, hum and noise. Steel develops a Search term:magnetic field when current passes through it, then when the current drops, the Search term:magnetic field collapses and dumps that energy into the conductor as electricity. This equals noise in an audio application.

Highly unlikely! The person who wrote that either didn't try it or they got a cable with a broken shield... or the cables are unshielded which would be bad!

Steel as the shield should help with magnetic interference, but if it's only at the connector and the length of the cable is a bigger concern.

Constant magnetic fields aren't a problem but AC fields can transmit noise electro-magnetically or capacitively. And a coil (like the copper coils used in speakers, microphones, guitar pickups, etc.) doesn't have to be magnetic to pick-up a signal or noise. It just has to be in a magnetic field.

Steel has higher resistance than copper (or most metals) but the resistance depends on the cross-sectional area and length. Longer or thinner cables have more resistance. Connectors are "short" so any metal is usually fine. And resistance is only a concern for speaker wires (where the impedance is much lower compared to everything else).

Corrosion is also a consideration for connectors/contacts. That's one reason you don't often see bare copper contacts. And RCA connectors have to be springy to hold tight and make good contact.

 

[unpluggged]

Steel develops a Search term:magnetic field when current passes through it

Any conductor develops a magnetic field when current passes through it. It's a phenomenon discovered by Ørsted back in 1820 that is called electromagnetism and thanks to which we can have many nice things today, including mains electricity and sound reproduction.

I'd recommend not to worry too much about nonsense that some anonymous folks post on the Internet.

 

[raindance]

RCA connectors carry negligible current unless you have the most massive ground loop problem in the history of the multiverse, in which case you'd have other worries.

 

[MaxwellsEq]

Hi!
I was buying a couple of short RCAs and got curious when I read some reviews pointing out how the connectors were attracted to magnets.
Like this:

Check out this Amazon review of CESS-163-4i Low Noise 12 Gauge Premium RCA Audio Line Patch Cable (4 Inches)

Cheap metals!

www.amazon.com

Or this comment:
The cables are VERY WELL MADE *BUT* they used steel in the connectors that will absolutely result in buzzing, hum and noise. Steel develops a Search term:magnetic field when current passes through it, then when the current drops, the Search term:magnetic field collapses and dumps that energy into the conductor as electricity. This equals noise in an audio application.

Ferromagnetic material in speaker terminals has been known to have a measurable but inaudible impact at high power levels. For line level, any hysteresis should be negligible.