Humming sound from budget active speakers

[sgasser]

I'm pretty new to speakers. I have a humming sound coming from my active speakers (budget speakers T-200X https://www.flipkart.com/f-d-t-200x-140-w-bluetooth-soundbar/p/itm98a6aea73d694 [also has pictures of the connections on the backside]).

I've searched for solutions, but can't find any that work for me or that require a component costing more then the speakers themselves.
I've tried bluetooth and aux - both of them have the humming sound. I haven't tried USB.

I thought that it might be a ground loop problem, but the speakers are RCA powered and so putting a ground loop isolator between the speakers and the main unit did get rid of the hum, but it also lowered the volume by roughly 90% and the sound quality was awful. I also tried using another room's wall socket, but that didn't change anything. I don't know what else to try.

 

[ZolaIII]

It's probably bad implementations of class D amplifier having hummm (rising auditable distortion) in it's high's (and from speaker tweeters which you check simply by listening towards them from really close distance).
Did you mesure what they are outputting (white noise/not reproducing anything)?

 

[JayGilb]

What is the brand of isolation transformer you are trying ?
Many lower cost ones have poor frequency response (especially in low frequencies) and your hum reduction may just be part of the overall loudness reduction.

 

[Speedskater]

Are the speakers and the main unit powered from the same AC power wall outlet?

 

[sgasser]

What is the brand of isolation transformer you are trying ?
Many lower cost ones have poor frequency response (especially in low frequencies) and your hum reduction may just be part of the overall loudness reduction.

It's some really cheap one https://www.logingel.com/1465/168090/0/ShowProduct/Ground_loop_isolator

It's probably bad implementations of class D amplifier having hummm (rising auditable distortion) in it's high's (and from speaker tweeters which you check simply by listening towards them from really close distance).
Did you mesure what they are outputting (white noise/not reproducing anything)?

I did not take any measurements. I just know there's an audible hum at all times

Are the speakers and the main unit powered from the same AC power wall outlet?

The main unit/subwoofer is the only one that has a power cable. The speakers are rca powered through the main unit

 

[ZolaIII]

@sgasser yes but coming from where and sounding exactly how and you are able to hear it at what distance? Is it a 50/60 Hz hummm or high frequency tone? You can analyse/mesure what it is with your phone.

 

[sgasser]

@sgasser yes but coming from where and sounding exactly how and you are able to hear it at what distance? Is it a 50/60 Hz hummm or high frequency tone? You can analyse/mesure what it is with your phone.

Using some phone app it seems to be around 150Hz or 6.2kHz, I don't know how accurate that is. They're coming from my rca powered speakers. The head unit that has a subwoofer does not have the hum. Even 5 meters away I can hear it clearly.

 

[ZolaIII]

Well one at 150 Hz you probably can't hear far nor can the main wafer unit reproduce high one's that you can.
First one is from power supply, second one is as already described bad amplifier.
It's either broken or simply bad anyway I don't believe you will be able to fix it, sorry. I just sow obviously fake reviews on Amazon India about it.

 

[Speedskater]

So it's a 3 unit system? The main unit having the amplifiers and sub-woofer?
The cables with RCA connectors are speaker cables not interconnect cables (so the interconnect cable rules don't apply).
The isolation transformers are not designed for this.
It's not an RCA cable problem at all.
Does the system hum with no musical source plugged in?

 

[JayGilb]

So it's a 3 unit system? The main unit having the amplifiers and sub-woofer?
The cables with RCA connectors are speaker cables not interconnect cables (so the interconnect cable rules don't apply).
The isolation transformers are not designed for this.
It's not an RCA cable problem at all.
Does the system hum with no musical source plugged in?

It's a low quality isolation transformer and should be placed between your TV or whatever output device you are using and the input rca connectors on the sub/main unit.

 

[sgasser]

So it's a 3 unit system? The main unit having the amplifiers and sub-woofer?
The cables with RCA connectors are speaker cables not interconnect cables (so the interconnect cable rules don't apply).
The isolation transformers are not designed for this.
It's not an RCA cable problem at all.
Does the system hum with no musical source plugged in?

The hum is there when even when nothing is connected

Well one at 150 Hz you probably can't hear far nor can the main wafer unit reproduce high one's that you can.
First one is from power supply, second one is as already described bad amplifier.
It's either broken or simply bad anyway I don't believe you will be able to fix it, sorry. I just sow obviously fake reviews on Amazon India about it.

Wouldn't be surprised. Only paid 40 euros for it so it's not a huge loss, still useable

 

[AnalogSteph]

The hum is there when even when nothing is connected

That could be mechanical transformer hum then, not uncommon in cheap gear. If it's coming out through the satellites, it could be a bad capacitor in the power supply, too. Neither would be indicative of premium parts quality. (If using RCAs as passive speaker terminals wasn't enough of a giveaway, that is.)

Honestly this system seems to be trying to do way too much for something that sells for 110-120€ brand new. 2.1 with 35 W + 2x 17.5 W, BT, remote, lights, radio tuner, ... You can barely get a half-decent kitchen radio for that sort of money. The internals just about have to be the cheapest possible garbage. This is the sort of borderline scam product that tends to target young and inexperienced buyers... all bark and no bite. I am reminded of cheap cardboard-backed faux "component stereos" from the 1980s.

If possible, I would just return the whole thing. Then, give us a budget, where you are located and what exactly your requirements are. In this price class I would definitely be looking out for something on the used market, too.