Subwoofer hum ground loop issue?

[Lambda]

Because it defeats the basic purpose of the Safety Ground system!

Everything over a view volt diode drop gets Conducted to safety ground

In a Ground Fault (short circuit) failure it may be required to carry be required to carry 1000 Amps for a fraction of a second unit the circuit breaker trips.

that's why it has fast blowing fuse in addition to your regular fuse and GFCI.
Properly selected diodes can handle the current for a short period of time without doping more then a view Volts.

and does it have the required 'UL' or other safety agency listing?

I don’t know can i see the the UL list somewhere?

Is it legal to sell it in the US if not?

 

[Speedskater]

Everything over a view volt diode drop gets Conducted to safety ground
that's why it has fast blowing fuse in addition to your regular fuse and GFCI.
Properly selected diodes can handle the current for a short period of time without doping more then a view Volts.
I don’t know can i see the the UL list somewhere?
Is it legal to sell it in the US if not?

Oh dear, oh dear.
It's called Safety Ground for a reason.

 

[Lambda]

It's called Safety Ground for a reason.

This is totally not an answer to non of this.

Can you legally sell non compliment products in the US?
If they have to print "caution hot" on a coffee mug i don’t think thy can sell a "dangerous" non compliment products without a million warnings.
I can totally understand if this is non compliment bur then how can the sell it?

 

[thepiecesfit]

Some other things I’ve tried so far have not helped:

- plugging one device at a time, to the front surge protector.
- running extension cord to the front of the room so the subwoofer is on the same circuit.
- found old RadioShack ground loop isolator plugged from rca wall plate to AVR.

 

[pjug]

Ugh, it really sounded like a ground loop. Strange that the ground lifting is a solution. Going back to that, do you have a copper pipe available to try lifting ground and then strapping the ground on the adapter to the pipe (so grounding the subwoofer to the pipe instead of wall outlet ground). Others can comment on whether this is safe if it works. Probably it won't help anyway.

 

[thepiecesfit]

Ugh, it really sounded like a ground loop. Strange that the ground lifting is a solution. Going back to that, do you have a copper pipe available to try lifting ground and then strapping the ground on the adapter to the pipe (so grounding the subwoofer to the pipe instead of wall outlet ground). Others can comment on whether this is safe if it works. Probably it won't help anyway.

I still think it's a ground loop because I pulled out my MiniDSP 2x4HD from the closet and set a low pass filter at 50hz with BW 48 dB/Oct filter and the noise all but disappears perhaps a faint sound. Oh well will keep checking.

 

[pjug]

The radio shack isolator should have broken the ground loop though. I used the exact same Radio Shack device in a car years ago and it worked perfectly.

No reduction of the hum magnitude when you plugged into the same outlet as the AVR?

 

[Lambda]

should have broken the ground loop though

There should at least be a significant reduction in Noise.

thepiecesfit
Again what is the minimal setup that produces the problem?
AVR and SUB directly concrete together short cable same outlet. is there hum?
AVR and SUB concrete trough the cable in the wall and nothing else. is there hum?
SUB only connected trough the cable in the wall nothing else. is there hum?
SUB only connected trough the cable in the wall .cable shorted and grounded at the other side.

 

[thepiecesfit]

There should at least be a significant reduction in Noise.

thepiecesfit
Again what is the minimal setup that produces the problem?
AVR and SUB directly concrete together short cable same outlet. is there hum?
AVR and SUB concrete trough the cable in the wall and nothing else. is there hum?
SUB only connected trough the cable in the wall nothing else. is there hum?
SUB only connected trough the cable in the wall .cable shorted and grounded at the other side.

I'll need to get back to you on all that, trying to find some more time to isolate and run through all those workflows.

 

[buz]

Somehow my SB1000 picks up hum on the way from my pioneer lx505. Since the extent of the hum seems to depend on where the cheapo RCA cable goes, I am hoping that a better shielded RCA connection would help. Any pointers to such a cable in Europe (or possibly on aliexpress) without going for audiophile snake oil?

For example, would amazon basics (https://www.amazon.de/-/en/Amazon-B...4279&sprefix=Amazon+basics+sub,aps,229&sr=8-5) do the job?

Thanks a lot.