Does a junction box full of cables affect the Hi-Fi performance?

Dear Naim forum users,

I’m rebuilding the electrical system of my home and my electrician might need to put a big junction box full of electrical cables right next to my Hi-Fi plug.

According to your experience/opinion, might this have an impact on audio performance? I’m worried that it might do. I wonder if my concerns might be exaggerated…

Thank you very much in advance for any advice.

Hidden profile. Where are you based, regs are different by region, country etc.

I live in Italy.

How close? If more than a couple of cm I’m sure it won’t be audible.

What will these new cables be used for? If they will be supplying lots of SPMSs, fridge, microwave, LED lighting etc. then they may carry some electrical interference that could affect your HiFi. So where possible, it would be good practice to keep them well away from the HiFi and its wiring.

He told me to put just few centimeters far from the Hi-Fi plug, needless to say that I wasn’t happy at all. I think it could be possibile to move it as far as 1.5 - 2 meters away (right behind one of the Hi-Fi speakers), should that be enough to avoid electrical interferences? What’s the minimum recommended distance?

@ChrisSU This junction box will contain cables for half a floor: not fridges or microwaves, but surely LED lighting, ethernet cables, power cables for TVs and computers.

I’m sure 1.5 to 2m distance is plenty. How much less than that would be OK is hard to say. Of course, if you move the wiring to behind a speaker, you would want to keep it clear of the speaker cables too. Most important is to keep it away from the HiFi system, especially the source, preamp, and interconnects which carry delicate low level signals.

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I said to the electrician that I don’t want to put that junction box right next to the Hi-Fi plug, it would be too close to all the system. I don’t want to loose performance and that’s not acceptable for me.
If 1.5 - 2 meters is enough, I would go with that solution in the end.

Behind the speaker there will be nothing because the junction box will be inside the wall.
Could it be a threat for the speaker by the way? I would say no according to what you said.

2" to 3" should be plenty. This is an interesting read if you’d like to know why:


Thank you @ChrisSU!
@n-lot That PDF should be interesting indeed.

If the junction box is just that, with no switches, power supplies etc within, then it will have zero effect - though a multiplicity of wires, which is what its existence implies, will increase the electromagnetic field compared to a single cable, requiring greater distance to any unshielded sensitive electronics. But likely no worse than a multiplicity of power cables to an array of hifi electronics…

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There should be a power supply right next to the junction box but it’ll still be 1.5 - 2 meters far from the Hi-Fi. If the junction box and cables are shielded, should there be any problem? I would guess no considering what you said.

I don’t envisage any problem.

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If possible keep the ethernet and mains power cables running from the junction box apart.

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@Innocent_Bystander Thanks!
@Fatcat I’ll try, but I’m not entirely sure if that is possibile due to the available room. However the ethernet cable will be running directly from the router to my streamer to avoid interferences.

I was also wondering: how far should the AC socket be from the Hi-Fi? Better to consider everything.

What is a ‘Hi-Fi’ plug.
Do you mean the power plug that supplies the hifi, if so this is the same power as in the j-box, 50Hz.
Then you have to ask how many amps, as its amps that make a stronger or weaker magnetic field.
Then you need to know the length of cable distance between cables, a long side by side run has more induced interaction potential than a short run.
Compared to a 90 degree crossover that has no induction potential.
In between is a random jumble of wires typical of a j-box which has little real potential to do much.


I’m attaching a simple scheme of the room:

Walls are 5 meters long if you exclude doors and windows. The red dot is where the Hi-Fi Plug should be and the green rectangle is where the junction box might be located.
From the Hi-Fi Plug there will be a cable to the AC distribution block to which all the Hi-Fi devices power cords will be connected.

No problems whatsoever.


Even if the the amp will be very close to the Hi-Fi Plug?
You might want to know that there will be more than one plug in the red dot position (4-5 AC plugs, a couple of ethernet and one for the TV).