Need help eliminating the high pitch noise on my speaker (when turn on aircon)

[chatnever]

The noise only audible when I turn on the air conditioner.
I have already tried below:

• Plugged in a Power conditioner
• Plugged in different outlet
• Used ferrite beads when needed

I reallized it only happens when using AUX-RCA mode (ouput from my USB DAC), when switch to bluetooth, the noise dissappeared.

The Speaker is Hivi D100. Aside from turning off the aircon, how to eliminate it?

Here is the demo sound, thanks

https://voca.ro/1nKpX32z5pou

 

[Zek]

Try plugging the device into an outlet that is on another phase than AC.
Maybe the RCA cable is not well shielded, try a better cable.

 

[Doodski]

The noise only audible when I turn on the air conditioner.
I have already tried below:

• Plugged in a Power conditioner
• Plugged in different outlet
• Used ferrite beads when needed

I reallized it only happens when using AUX-RCA mode (ouput from my USB DAC), when switch to bluetooth, the noise dissappeared.

The Speaker is Hivi D100. Aside from turning off the aircon, how to eliminate it?

Here is the demo sound, thanks

https://voca.ro/1nKpX32z5pou

Does your DAC have fiber optic input. If you use that then you isolate the source from the DAC and eliminate that part of the situation. Does the distortion sound still come through when the input to the DAC USB connection is disconnected?

 

[Keith_W]

Isn't that interesting. 8kHz fundamental + 16kHz harmonic. I don't have a good explanation for this, it's way too high to be a ground loop. My guess is some kind of cable inductance.

 

[Roland68]

The noise only audible when I turn on the air conditioner.
I have already tried below:

• Plugged in a Power conditioner
• Plugged in different outlet
• Used ferrite beads when needed

I reallized it only happens when using AUX-RCA mode (ouput from my USB DAC), when switch to bluetooth, the noise dissappeared.

The Speaker is Hivi D100. Aside from turning off the aircon, how to eliminate it?

Here is the demo sound, thanks

https://voca.ro/1nKpX32z5pou

Known problem with air conditioning systems, poor interference suppression, incorrect connection or defective.
It is best to eliminate it at the source so that such strong emissions do not occur in the first place. It is also likely to exceed the legal regulations and limits for interference emitted into the power grid and EMC in most countries.

View attachment 386962

Isn't that interesting. 8kHz fundamental + 16kHz harmonic. I don't have a good explanation for this, it's way too high to be a ground loop. My guess is some kind of cable inductance.

Completely normal for such disturbances.

 

[restorer-john]

View attachment 386962

Isn't that interesting. 8kHz fundamental + 16kHz harmonic. I don't have a good explanation for this, it's way too high to be a ground loop. My guess is some kind of cable inductance.

Love the new avatar!

I found the inspiration. Michael Jackson's thriller orignal video. I remembered the move...

 

[Moonbase]

Well the good news is that you know the source of the noise. 8k makes me think it a switch mode power supply causing the issue. Maybe using some ferrite beads on the power cable might help.

 

[chatnever]

Does your DAC have fiber optic input. If you use that then you isolate the source from the DAC and eliminate that part of the situation. Does the distortion sound still come through when the input to the DAC USB connection is disconnected?

Mine is Tempotec Sonata III, which have 01 aux output only. When disconnect the DAC, the noise significantly reduce, or not audible at all.

And one more thing is that, when having music play, the high pitch noise went away immediately. When music stop, it come back.

PS: I search elsewhere they said ground loop isolator might help, but I don't understand how it works, and would it change the audio quality?

 

[Moonbase]

In the OPs case an isolator seam unlikely to solve the issue. I have had issue in the past and a process of elimination traced it to my phone charger. That affected the dac. In my old amplifier , that could a solution for you. Sadly it’s a process of elimination .
Plugging in all the components using one wall socket is a start, then turn everything off that you can reasonably do.

 

[gr-e]

And one more thing is that, when having music play, the high pitch noise went away immediately. When music stop, it come back.

Sounds like your dac mutes the output when there's no audio, and the input on your speakers is left floating.
You can try a software solution to keep the audio stream alive (Sound Keeper, for example). Personally, I'd just use the speakers' built-in dac instead.

 

[Philbo King]

In case nobody said it yet:
Make sure there's no Taylor Swift CD in the player. A frequent cause annoying high pitched sounds...

 

[jamesdyson]

View attachment 386962

Isn't that interesting. 8kHz fundamental + 16kHz harmonic. I don't have a good explanation for this, it's way too high to be a ground loop. My guess is some kind of cable inductance.

Usb packet noise. A usb isolator will fix it. Suspect air-conditioning a coincidence

 

[Cbdb2]

Usb packet noise. A usb isolator will fix it. Suspect air-conditioning a coincidence

The noise only audible when I turn on the air conditioner

That would be some coincidence.

 

[Cbdb2]

Sounds like your dac mutes the output when there's no audio, and the input on your speakers is left floating.
You can try a software solution to keep the audio stream alive (Sound Keeper, for example). Personally, I'd just use the speakers' built-in dac instead.

To float an input would be bad design it should mute to ground. Is the noise there if you disconect the dac but leave the RCA cables attached to the speakers this is floating the input, does the noise change (power down
the speakers before you do this)? What if you short the floating end of the RCA?

 

[chatnever]

In an unexpected move, I choose to switch to my new arrival Tempotec BHD Pro (for the new IEM), the noise disappeared immediately.

I guess the Sonata HD III has some kind of flaw in its design.

 

[Lux_ury]

From my memory an Aircon will have a hard start on a compressor, which uses a start capacitor to jump start the high amps used to get it going? I was always advised to have an isolator and separate the mains ring to isolate any issues on a domestic ring which is why its on a separate MCB and consumer unit.

"An MCB is an automatically operated electrical switch. Miniature circuit breakers are intended to prevent damage to an electrical circuit as a result of excess current. They are designed to trip during an overload or short circuit to protect against electrical faults and equipment failure"

I'm not a electrician so always get a pro in to advise and do the work!
Plus the fans alone can cause interference?

Talking about a evaporator inside and a condensor outside.
Plug in types will still draw 9 10 amps (high BTU) starting? Just to test if it's a plug type get a 20m extension 13amps lawn mower one and take the aircon outside away from the house turn it on and see if you get the interference if yes then its the plug, if not its the aircon unit.

 

[jamesdyson]

In an unexpected move, I choose to switch to my new arrival Tempotec BHD Pro (for the new IEM), the noise disappeared immediately.

I guess the Sonata HD III has some kind of flaw in its design.

it's letting through usb packet noise on the gnd

 

[chatnever]

it's letting through usb packet noise on the gnd

Dammmmmm!

The easier solution is just… switch to a high quality “German custom made” cable, I purchased just for 5 dollar.

I don’t even know why it work though

 

[AnalogSteph]

I'm guessing the new chunky boi cable may have substantially better / lower-resistance shielding, which is usually beneficial with unbalanced connections. The offending whine may have been part of power supply mains filter leakage current from the speakers making its way back to the computer via the audio cable. Then the amplitude of interference is pretty much going to be directly proportional to shielding resistance. A piece of bare wire touching both the computer chassis (or exposed grounds) and e.g. RCA sleeves on the speaker should have much the same effect when used with the old cable, assuming good contact on both ends.

An unbalanced audio input only knows about the voltage difference between signal and ground. If for some reason there is additional current running over the shield that is generating a voltage drop according to Ohm's Law, that voltage cannot be distinguished from an actual signal coming from the source. Typical floating SMPS have 1-4.7 nF of coupling capacitance to mains, which effectively forms a complex voltage divider with shield resistance if the computer on the USB is grounded.
Even if the computer should be floating, good shielding would be beneficial - if your system's ground potential is floating, you could have capacitive coupling from your signal wires to the outside world, like the literal ground they are on. Good shielding forms an effective Faraday cage and as such prevents the signal from "seeing" anything outside. This is particularly important if the output is turned off and impedance on the signal wires is limited only by speaker input impedance, which could mean 10 kOhms or more instead of a few ohms. It's about the difference between trying to move a pack of melamin sponge (magic eraser) or cotton wool vs. a same-size block of solid steel or lead (and actually, it could be as much as the difference between solid air and solid lead). This is why passive speakers are using nothing more than twin lead for wiring, any external capacitive coupling has to fight a fraction of an ohm of output impedance and speakers aren't exactly sensitive (you'd typically need about 0.4 mV just for 10 dB SPL at 1 m).

BTW, it's funny how the electronics are the smallest thing in the entire setup, being dwarfed even by the cable...

 

[chatnever]

I'm guessing the new chunky boi cable may have substantially better / lower-resistance shielding, which is usually beneficial with unbalanced connections. The offending whine may have been part of power supply mains filter leakage current from the speakers making its way back to the computer via the audio cable. Then the amplitude of interference is pretty much going to be directly proportional to shielding resistance. A piece of bare wire touching both the computer chassis (or exposed grounds) and e.g. RCA sleeves on the speaker should have much the same effect when used with the old cable, assuming good contact on both ends.

An unbalanced audio input only knows about the voltage difference between signal and ground. If for some reason there is additional current running over the shield that is generating a voltage drop according to Ohm's Law, that voltage cannot be distinguished from an actual signal coming from the source. Typical floating SMPS have 1-4.7 nF of coupling capacitance to mains, which effectively forms a complex voltage divider with shield resistance if the computer on the USB is grounded.
Even if the computer should be floating, good shielding would be beneficial - if your system's ground potential is floating, you could have capacitive coupling from your signal wires to the outside world, like the literal ground they are on. Good shielding forms an effective Faraday cage and as such prevents the signal from "seeing" anything outside. This is particularly important if the output is turned off and impedance on the signal wires is limited only by speaker input impedance, which could mean 10 kOhms or more instead of a few ohms. It's about the difference between trying to move a pack of melamin sponge (magic eraser) or cotton wool vs. a same-size block of solid steel or lead (and actually, it could be as much as the difference between solid air and solid lead). This is why passive speakers are using nothing more than twin lead for wiring, any external capacitive coupling has to fight a fraction of an ohm of output impedance and speakers aren't exactly sensitive (you'd typically need about 0.4 mV just for 10 dB SPL at 1 m).

BTW, it's funny how the electronics are the smallest thing in the entire setup, being dwarfed even by the cable...

Thanks for the info, new knowledge to me.