Strange problem speaker make noise with no wires connected.

[Ssmokeyy]

Building a theater room for a friend. 15 x 20 Doors back to the left of the room. The corner next to the doors speakers make a hiss noise not evern connected to wires. No other spots in the room does this happen. I have had 2 other people listen to this noise to make sure its not me. The room has its own 150 amp panel, it's own ventilation not connected to the rest of the house, mini split to control the room temp, 3 layers of sheet rock. I have moved other speakers into said corner and they also make noise once u move them out of the corner they stop making noise. None of the cat 6 cables have been connected to the network yet. Neither of the xlr or rca cables going to the sub have been connected to anything either. Has anyone had this happen to them? I did turn off all the power to this room and no change.

 

[Blumlein 88]

Does it go away if you short the speaker terminals?

 

[JSmith]

I have moved other speakers into said corner and they also make noise

What is under or above that corner? A/C, water heaters, large power transformers, power wires or anything like that?

Sounds like electromagnetic induction, which is why it dissipates when the speaker is moved away from the source.


JSmith

 

[restorer-john]

We've been through this recently. See here:

McIntosh Transformer causing noise in speakers while disconnected.

EDIT: **Amp is plugged into wall outlet using stock cable, as per manual - I switched to the high current isolated bank of the Panamax MAX5300PM, still noise, then used Blizzard AQ Power Cable, still noise, went back to wall and stock cable** See pictures: What am I scientifically dealing...

www.audiosciencereview.com

 

[Ssmokeyy]

Concrete floor with carpet. Tripple layer 5/8 soynd rated sheet rock wall. Hat channel and mass loaded vinyl. There is a hvac duct in the ceiling in that. Corner. I built a box around it using wood/rubber brackets and than lined it with mass mlv than 3 layers of rock. One side of the wall is the rec room nothing close to the wall in that room. Other wall is mech room. Hot water tank is 2 feet from that wall also two ft IA the hvac main parts. Ceiling in that corner er is lower than the rest of that room 6.5 ft ceiling rest of the room is 8 ft

 

[JSmith]

Best to track down the source;

https://www.aliexpress.com/item/1005006528896246.html

JSmith

 

[Ssmokeyy]

I got one off amazon. It doesn't pick up anything in that corner. But I did find that in the room outside of the theater the noise gets worse. It's in the middle of the wall between the livingroom and the stairs. I might open that wall to see what's in there.

 

[BR52]

First I would shorten the input terminals to change the internal impedance of the system.
Some lines feeding a HVOC can emit a lot of HF.

 

[Ssmokeyy]

We might open the wall. Its crazy these speakers pick this up with nothing connected to them. U can just walk around the house holding the speaker. Is there anything we can hang to block this kinda problem from passing the in the wall? I was thinking something lead lined.

 

[Blumlein 88]

We might open the wall. Its crazy these speakers pick this up with nothing connected to them. U can just walk around the house holding the speaker. Is there anything we can hang to block this kinda problem from passing the in the wall? I was thinking something lead lined.

Did you ever try shorting speaker binding posts or connecting to an amplifier? The noise may disappear or be greatly diminished. In which case, nothing to worry about.

 

[Ssmokeyy]

I did with the amp. Noise is still there but no i didn't try shorting the terminals. I will next time i head there.