Question Audio noise coming out of laptop when connected to a subwoofer while charging

[Teekiii]

I have a (Legion 5-15ITH6H Laptop (Lenovo) - Type 82JH ), when I connect the headphone output to a subwoofer with two speaker, I hear a continues noise when the laptop has no media playing , that noise disappears when I play any media on the laptop then it comes back after almost 30 seconds when the media is off, How can I fix that? knowing that I use the same subwoofer on the PC and none of that noise ever happened when the pc is on (but it happens when the pc is shutdown and the speakers are at high volume, I hear the same noise).

I googled it and tried chat GPT, and it suggested some problems, I tried to trouble shoot some of them, like trying a ferrite beads, match the power outlet for both the subwoofer and the laptop and still noise, and it happens when the laptop is charging, knowing that we don't have a ground port in our power sockets here in Egypt its very rare, so I understand that it might be a ground loop but how can I be sure? specially that ground loop isolators seems to be rare to buy online here so I have to buy them from abroad.

Thanks in advance,

 

[kira-faye]

It's not a ground loop if you don't have a grounded system. Chances are it's just interference. Get some aluminum foil and cover the computer / the speakers when you hear the sound, if it goes away it's a shielding issue. You might be able to open the speakers and shield just the amplifier section.

 

[punkncat]

When you say 'ferrite beads" is this the same as a "choke"?
The choke is a magnetic band that you snap around the cable to help block such interference. Like a little tube, as it were.

Amazon.com

 

[Teekiii]

When you say 'ferrite beads" is this the same as a "choke"?
The choke is a magnetic band that you snap around the cable to help block such interference. Like a little tube, as it were.

Amazon.com

No its not like that, its a ferrite beads I took from old laptop charger wire

 

[Teekiii]

It's not a ground loop if you don't have a grounded system. Chances are it's just interference. Get some aluminum foil and cover the computer / the speakers when you hear the sound, if it goes away it's a shielding issue. You might be able to open the speakers and shield just the amplifier section.

okay, i'm going to try that, but for now I 'm using the HDMI audio output and the problem disappeared, does that helps in detecting the problem?

 

[punkncat]

No its not like that, its a ferrite beads I took from old laptop charger wire

I had to go look it up, but they are the same thing.

Is the HDMI wire you are using shielded?

If you plug headphones into the laptop jack, do they also hum?

 

[Teekiii]

I had to go look it up, but they are the same thing.

Is the HDMI wire you are using shielded?

If you plug headphones into the laptop jack, do they also hum?

Good to know they are the same.
Idk if its shielded or not, but I don't think so because its just a short converter as you can see it here converter
the headphones are super clear with no noise at all,
but I should mention that the jack I use for the subwoofer is TRS 3 pole, and for the headphone TRRS4 pole if that would help.

Thanks

 

[punkncat]

Hmm, are the connectors for the equipment compatible with the 3 or 4 pole?

I know if you take a headphone connector and pull it slightly where those become unaligned it can cause noise.

The possibility that I consider here is that the laptop charger and or power delivery is inducing hertz cycle. You don't hear it on the headphones because it is a low power output. My thoughts are that your sub/speaker set are powered (amplified) and are increasing the noise level of it enough to be heard.

Do you know anyone with a battery backup + power conditioner that you can go visit? Plug the laptop and the speakers into battery outputs and see if the noise continues.

 

[Teekiii]

The audio output (Female 3.5 mm) in the HDMI converter is 3 pole, the one in the laptop is 4 pole as it supports a headphone with mic. the 3 pole male jack of the subwoofer (the one with remax word on) goes in the both of the outputs just fine, also the 4 male jack of the headphone pole goes into the converter output and works fine too.

I can understand your explanation.
But unfortunately I can't facilitate such a test because idk anyone or any shop that has these this kind of UPS.


Why when I use HDMI which uses Nvidia high definition audio, it doesn't make such noise, with the same condition of the same subwoofer and the laptop charger plugged in, can it be related to the motherboard audio driver which is realtik?