What Types of Cables are Susceptible to EMI?

[Al ears]

What??

Please feel very free to explain

 

[Revolutions]

Please feel very free to explain

View: https://youtu.be/yCsfTMk9gKo?feature=shared

 

[riverofwind]

AFAIK it’s more about unwanted noise reaching components like DACs further along the digital chain.

This is what I'm talking about. To remove this effect I hooked up USB power to my UPS and audio signal to digital optical on the computer. I'm curious if using USB power in this way removes the unwanted noise or not, and also the same for digital coax instead of digital optical. Something you might know? Thanks!

 

[boband212]

Hi I have a quick question - what types of the below mentioned cables are susceptible to electromagnetic interference from being in close proximity to power cables in cable management setups? Does the EMI just interfere with the signal and therefore decrease its quality and max length? Does it have more of an impact on analog signals than digital signals? All the cables I could dream up include:

HDMI/Displayport
3.5mm mini jack audio cables
Speaker Wire
Ethernet (stp vs utp)
Phone
USB
Coaxial
Digital Coaxial
Digital Optical (obviously not)
Component Video and RCA/Composite kinda non-existent nowadays

Thanks!

If this helps anyone I am glad. I have several amps. When connected an Onkyo amp has a slight hum in the transformer. When plugged into the power source and turned on there is no hum. After some experimenting I determined it is emi from the speaker cables. The speaker wires run behind a wall unit (done before my time) and come into contact with power cords and TV cable. Speaker cables should not be close to power cords or other cables. Speaker wires can run side by side, but need to be away from any other cables. A Rotel amp and a Yamaha amp do not hum. Those must have better shielding. An easy fix is to cross the wires for one speaker- red to black and black to red at amp and speaker. Emotiva sells a power strip with EMI filter- if in stock. I would first think of speaker cables. All of the connection cables should be apart from power cords.

 

[Juzzie Wuzzie]

FWIW I have "intermingling" of power, interconnect and speaker cables ... and there are no issues.

 

[boband212]

FWIW I have "intermingling" of power, interconnect and speaker cables ... and there are no issues.

As I mentioned I have a Rotel and a Yamaha that do not hum, but an Onkyo that does. Your amp must be well shielded. Good for you. But all the same when speaker cables are in contact with power cables it can cause a hum.

 

[nopiano]

As I mentioned I have a Rotel and a Yamaha that do not hum, but an Onkyo that does. Your amp must be well shielded. Good for you. But all the same when speaker cables are in contact with power cables it can cause a hum.

But that’s exceptionally rare. Much more common is for signal (interconnect) cables to pick up hum. That’s because speaker cables already carry signals post-amplification.

 

[boband212]

But that’s exceptionally rare. Much more common is for signal (interconnect) cables to pick up hum. That’s because speaker cables already carry signals post-amplification.

Yes, it is not so common. Depends on how well the amp is shielded. Shielded speaker cable is sold and this is why. If one digs deep enough there are articles on this subject. I can plug the Onkyo amp into the power socket, turn it on- no hum. I can connect the CD player- no hum. I can connect the turntable- no hum. I connect the speakers and there is hum. So what would you deduce? I asked a friend who owns a business building speakers and amps- Genesis. He said that speaker cables can pick up emi and carry it to the amp. One article I read said a lot about running speaker cables inside a wall in the home. It said to keep the speaker wires apart from power wires. If it is not a problem for you then why siscuss it? I would still suggest keeping some distance between interconnects and power wires and speaker cable and power wires. My setup was done beforre my time by my wife's first husband. Now I have to figure out how to arrange the cable which are behind a huge wall unit. The slight hum is only in the transformer. It does not come through the speakers. I want to resolve the problem all the same. My wife and I both like this Onkyo Integra amp really well. It is so mellow and clear with good bass. We listened to several different amps and bought a couple to listen to at home. Now I have 3 amps to sell. You only need 1 inch space from a power cords. If your speaker wire is good then it might not pick up emi from power cords. All I ever intended to say was that is it "possible".

 

[nopiano]

Yes, it is not so common. Depends on how well the amp is shielded. Shielded speaker cable is sold and this is why. If one digs deep enough there are articles on this subject. I can plug the Onkyo amp into the power socket, turn it on- no hum. I can connect the CD player- no hum. I can connect the turntable- no hum. I connect the speakers and there is hum. So what would you deduce? I asked a friend who owns a business building speakers and amps- Genesis. He said that speaker cables can pick up emi and carry it to the amp. One article I read said a lot about running speaker cables inside a wall in the home. It said to keep the speaker wires apart from power wires. If it is not a problem for you then why siscuss it? I would still suggest keeping some distance between interconnects and power wires and speaker cable and power wires. My setup was done beforre my time by my wife's first husband. Now I have to figure out how to arrange the cable which are behind a huge wall unit. The slight hum is only in the transformer. It does not come through the speakers. I want to resolve the problem all the same. My wife and I both like this Onkyo Integra amp really well. It is so mellow and clear with good bass. We listened to several different amps and bought a couple to listen to at home. Now I have 3 amps to sell. You only need 1 inch space from a power cords. If your speaker wire is good then it might not pick up emi from power cords. All I ever intended to say was that is it "possible".

Are we at cross purposes here? Are you describing mechanical hum from the amp transformer? I was referring to audible hum through the loudspeakers.

 

[boband212]

Are we at cross purposes here? Are you describing mechanical hum from the amp transformer? I was referring to audible hum through the loudspeakers.

I am talking about transformer hum. Under some conditions speaker cables can carry emi to the amp causing a hum in the transformer. When in-home installers are running speaker cables inside walls they take care not to run the speakers wires along with wire carrying current. I have nothing more to say about this. Hum in the speakers could be a number of things- a capacitor, the turntable. Sometimes an amp can be grounded to the chassis of a CD player, or a water piple. EMI filter can be expensive if the EMI is coming from the power outlet. I remember in the old days many amps and receivers had slight hums. This old Onkyo I have is from 1987. I want to get something new that has a similar sound- very warm and mellow. But a new amp would have to be under a $100 and fit into my cabinet. Take care. Enjoy some music. I have garden work to do now. I do not know why, but when it comes to "hum" people automatically think it about noise in the speakers.