Electromagnetic noise/ interference

[ApocalypticKatana]

I've thought of that or fine copper mesh surrounding the room, or using conductive paint underneath a coat of regular paint. I've even thought of building a room inside our garage or basement but until I know where the RFI is coming from it's like shooting in the dark.

Occasionally I'll hear my phone bleeding into something but it's a completely different sound, more like a chatter than a steady noise.

That’s a smarter alternative to use conductive paint

I’m No expert on the field though

 

[Greg Ferguson]

That’s a smarter alternative to use conductive paint

Well, I don't know for sure that it'd work for that purpose, but it seems like it would.

My room is above our basement, which houses our ancient heater and AC exchange unit, plus I have no idea what other wiring. It's a cool old house, and has suffered many "improvements" in the utilities in the house over the years, and some were definitely not to code, especially modern ones. And the floor is very old oak strips so I dare not cover those, and the ceiling is ancient pine boards… so I just don't know how effective shielding the walls would be if the ceiling and floor are unshielded. I guess it's time to get ideas from some friends who have recording studios.

 

[ApocalypticKatana]

Well, I don't know for sure that it'd work for that purpose, but it seems like it would.

My room is above our basement, which houses our ancient heater and AC exchange unit, plus I have no idea what other wiring. It's a cool old house, and has suffered many "improvements" in the utilities in the house over the years, and some were definitely not to code, especially modern ones. And the floor is very old oak strips so I dare not cover those, and the ceiling is ancient pine boards… so I just don't know how effective shielding the walls would be if the ceiling and floor are unshielded. I guess it's time to get ideas from some friends who have recording

Maybe , I mean it’s in our guitars (conductive paint) but at a smaller scale

I guess it depends if the direction of the interference signal was coming from the wall side .. then maybe it’ll help to line it with conductive paint , mesh etc to help combat the noise.

Though it wouldn’t be a faraday “cage” anymore if ceiling and floor was left unshielded

Again no expert but good luck with that!

For the OP of this thread maybe if you can find the direction of the interference, try blocking that side with some sort of metal, conductive paint , copper mesh … if you can’t relocate … just throwing out ideas here

 

[Bobbyoso]

Time for an ECM-capable Fractal...

 

[touch33]

A Story — during the recording of Donald Fagen’s “The Nightfly” they had issues similar to yours:

******************************
(from Wikipedia)
Larry Carlton performs lead guitar on much of the album and recorded his pieces in four days. During his time with the group, he discovered a humming sound coming from his amplifier. The engineers discovered the source on the outside of the building: a large magnet "that formed part of the New York subway system."
******************************

I know this doesn’t help, but it’s nice to know you’re in excellent company…no?

 

[rickboot]

If all else fails, you can create a cone of silence.

Emf Canopy Rf Shielding

A Story — during the recording of Donald Fagen’s “The Nightfly” they had issues similar to yours:

******************************
(from Wikipedia)
Larry Carlton performs lead guitar on much of the album and recorded his pieces in four days. During his time with the group, he discovered a humming sound coming from his amplifier. The engineers discovered the source on the outside of the building: a large magnet "that formed part of the New York subway system."
******************************

I know this doesn’t help, but it’s nice to know you’re in excellent company…no?

The spooky voice on the intro to into Satriani's Flying in a Blue Dream is from RF interference.

The intro heard was not planned, but was recorded nonetheless by producer John Cuniberti while recording Satriani's guitar parts for the song. Apparently, Satriani's amplifier was picking up a frequency from a radio or TV station, and Cuniberti simply said, "I'm recording this," and proceeded. Amidst the recorded speech is a young boy's voice saying "sometimes afterwards they still like each other, and sometimes they don't."

https://en.wikipedia.org/wiki/Flying_in_a_Blue_Dream_(song)

 

[Bobbyoso]

A Story — during the recording of Donald Fagen’s “The Nightfly” they had issues similar to yours:

******************************
(from Wikipedia)
Larry Carlton performs lead guitar on much of the album and recorded his pieces in four days. During his time with the group, he discovered a humming sound coming from his amplifier. The engineers discovered the source on the outside of the building: a large magnet "that formed part of the New York subway system."
******************************

I know this doesn’t help, but it’s nice to know you’re in excellent company…no?

All due respect, but having spent a great deal of time on NYC subways until I left the city for good, the concept of a correlation between the subway system and "excellent company" is pretty alien to me. ;-)

 

[touch33]

All due respect, but having spent a great deal of time on NYC subways until I left the city for good, the concept of a correlation between the subway system and "excellent company" is pretty alien to me. ;-)

That’s why there isn’t one in my post.

 

[Bobbyoso]

That’s why there isn’t one in my post.

Alrighty then! Have a nice day.

 

[unix-guy]

Alrighty then! Have a nice day.

He was referring to Larry Carlton

 

[Boomer]

My desktop computer case was the cause of my problems. Everything was painted on the case so it had bad grounding. This was on top of having a glass side panel, which a ton of GPU noise made it through.

My rackmount server case has provided better results compared to the old L337 gamer RGB rainbow puke case.

Stock Dell laptop power supplies (experienced with multiple of them) also give me a ton of EMI, somehow my wife's HP supply doesn't though.

 

[Boomer]

One more thing is I get dirty power every once in a while since I have a fire station right behind my house. Whenever they run maintenance on their generators I get the worst EMI known to man.

Good tone if you like Firehouse though.

 

[unix-guy]

One more thing is I get dirty power every once in a while since I have a fire station right behind my house. Whenever they run maintenance on their generators I get the worst EMI known to man.

Good tone if you like Firehouse though.

Dirty power and EMI are different things...

It may be EMI from large generators being run nearby.

 

[Bobbyoso]

He was referring to Larry Carlton

Understood, it was an apparently ill-advised attempt at humor on my part, I guess.

 

[Oscar Martinez]

I'm not exactly sure where that transformer is located. I have another association meeting tomorrow night and I'm going to ask the question. There is somebody there who knows exactly where it is. I intend to find out!

Hey did you ever figure out your EMI issue? I've been thinking about upgrading from the axe 2 to the axe 3 because of its "Improved noise gate in the Input block, now also includes EMI filtering", dealing with a quite irritating EMI issue right now in my setup. I tried a Microtron hush pedal someone else suggested and, while it works, it takes a bit out my tone and doesn't solve the issue for one guitar in particular. Curious to see if you ever figured this out and what helped!

 

[Bking7string]

I was haunted by EMI interference for year and a half. Drove me crazy, tried everything from shielding my guitar cavities in copper foil, Faraday caps on all my cables, some emi fabric I draped on the wall behind my studio desk. Then one day I unplugged the refrigerator in the kitchen, which is on the other side of my home studio room, then boom silent! Ended up moving my studio desk to other side of the room, and moved the kitchen refrigerator to a wall further away. Been good ever since.
It has to be some type of appliance in one of the neighboring apartments. Goodluck!

 

[SteveW]

Hey did you ever figure out your EMI issue? I've been thinking about upgrading from the axe 2 to the axe 3 because of its "Improved noise gate in the Input block, now also includes EMI filtering", dealing with a quite irritating EMI issue right now in my setup. I tried a Microtron hush pedal someone else suggested and, while it works, it takes a bit out my tone and doesn't solve the issue for one guitar in particular. Curious to see if you ever figured this out and what helped!

Nope, the problem is there and it's worse in one room but it's pretty bad throughout the entire condo. With everything in the place shut down, and only a UPS powering the amp and speakers, I still have the same problem. It's coming from the pickups on every single guitar so I know it's an emi problem. The noise gate helps, but it doesn't reduce noise, it just masks it when the guitar goes quiet. It's not a solution, and at the moment I don't have one either.

 

[LiamH]

@Oscar Martinez, @SteveW, I really do feel your pain. I had a home studio built in 2021, and then spent the following 2 years trying absolutely everything to fix an RF EMI issue. Even though I knew the exact source of the noise, trying to find anyone to help me do anything about it was hard. Even though I knew the source was the inverter in the HVAC system, I spent a long time trying to figure out where the EMI was radiating from, because it was so thoroughly spread through the studio live room. (And that was after eliminating earth loops, etc.)

@Oscar Martinez, Axe FX II, Axe FX III, I even had to drag out a Fender Princeton, Ibanez TS-10 and a couple of guitars before the electrician would believe it wasn't my equipment causing the problem. He tried to get me to buy some cheap mains filtered power strips, and then came back asking if I'd ever heard of a thing for guitars called a "noise gate" at one point. I had to show him how noisy the EMI was on a fading note. If the gate is open and you want to hear guitar, the EMI is really, really annoying.

We tried every earthing scheme available, including giving the HVAC system its own earth, and filtering first the mains supply to the HVAC, and then the mains supply to the studio. I spent a lot on trying different wiring. It's mains electricity, so I didn't want to do it myself, and used a qualified electrician at great expense. The importers of the HVAC system, the HVAC installers, and then another HVAC "expert" were all completely perplexed. I was stuck, and no-one seemed willing or able to help.

The problem was almost completely resolved when I engaged a 3rd HVAC business to temporarily remove, and then relocate the outdoor HVAC compressor unit. I already mentioned in a post above, they found the wiring between indoor and outdoor units should have been screened, but wasn't. It seems the wiring to the indoor "cassettes" for the ducted HVAC system was transmitting a lot of HF inverter switching noise.

Electric guitars are a slightly unique problem nowadays. Given no-one listens to FM, let alone AM radio nowadays, they seem to be the last thing left that is badly affected, so I'm not sure anyone cares so much about emitting a lot of RFI/EMI from equipment and wiring. Balanced output microphones have really good immunity, and most other musical sources seem really good too. Electric guitars, however, even with humbuckers, act as pretty good aerials. Even with a human being attached as part of the low pass filter network, there's relatively limited attenuation.

If you are going to avoid problems, you have to find the source of the interference. Evidently slightly detuned transistor radios can be good for this, but in my own investigations, nothing better than a Stratocaster with a bit of gain at the amp moved around the rooms and rotated through the electromagnetic fields. I was lucky that I knew switching the cooling or heating off on the HVAC system silenced the noise completely. It still took a very long time figure out the cure.

Not sure if that helps anyone. @SteveW, it drove me to distraction. Could you ask all your neighbours to turn their fridges off at different selected times of day? I'll bet it's something annoyingly simple and easily curable, but that doesn't stop it being almost impossible to find.

Liam

 

[Guit'rilla]

Especially if it has a see-thru case so you can see its innards

Lot's of PCs throw off quite a bit of EMI, and single coils soak them up like a sponge. My Dell XPS has a metal chassis, but a crappy plastic front cover. My solution was to show it some copper shielding tape love on its face (with a copper skunk stripe run to the unpainted chassis in the back for grounding). Actually worked quite a bit better better than I expected it to to reduce computer induced EMI, which would increase significantly when opening Reaper. My favorite part: Poking 420 holes in the shielding for the air circulation . . .

 

[playmusic]

Total drag when the noise is coming from outside your home and you have no control over it. How do you feel about tin foil wallpaper? Ok with it on the floors and ceilings too?

In all seriousness though, I've seen Farraday fabric for sale on Amazon. Have no idea if it is legit or not. If so, I wonder if anyone has tried constructing a frame and using this fabric to build a small DIY Farraday cage to block EMI. Apartments and condos can definitely leave you at the mercy of a neighbor's problematic lighting or appliances.