Skip to main content

How to remove electrical noise in recording

Hi,
I am hearing some electrical noise through my speakers. I am using Shure sm57 dynamic mic which is connected to Focusrite saffire pro 14 interface. When I touch the microphone out pin, I hear this noise is getting reduced. I suspect this issue is due to some ground loops. Can any one suggest me how to get rid of this ? Do i need to use any ground loop isolation ? how to connect that to my setup ?

Comments

Boswell Mon, 10/09/2017 - 09:25

What form of noise is it? Hiss, hum, buzz..?
What do you mean by "touch the microphone out pin"?
Are you using a tested XLR-XLR cable between the SM57 and the Saffire microphone input?
Is the Saffire connected to a laptop or to a desktop (tower) computer? If it's a laptop, does it make any difference running on batteries, i.e. unplugging the mains adaptor?
Is the Saffire power supply correctly grounded through its power inlet cable?

You should not need any ground loop isolation.

IndianFluteGuy Fri, 10/13/2017 - 08:49

Its Hiss sound...

Boswell, post: 453287, member: 29034 wrote: What do you mean by "touch the microphone out pin"?

I mean when i touch microphone xlr pin on any of side (mic side or interface side) or even i hold mic in hand the noice getting reduced.

Boswell, post: 453287, member: 29034 wrote: Is the Saffire connected to a laptop or to a desktop (tower) computer? If it's a laptop, does it make any difference running on batteries, i.e. unplugging the mains adaptor?

You pointed out it here . There is difference when laptop running battery only.
the hizz noice completely getting removed when laptop running battery. Is there any issue with my laptop power adapter.
Both laptop power adapter and saffire interface adapter is connected to single power extension.

Do i need to replace the power adapter? or any other solution left with me ?

Boswell Fri, 10/13/2017 - 09:31

I can think of two things you could do:

(1) Try different laptop power supplies until you find one that does not give the problem.

(2) Use a USB isolator so that there is no ground connection that could transfer ground noise between the laptop and the interface. The one I have is an Alldaq high-speed USB2.0 isolator.

Edit: Sorry, I just realised your interface is FireWire and not USB. Scrub the second option. I'll leave the reference there because it may be useful to others who have a USB audio interface.

IndianFluteGuy Fri, 10/13/2017 - 23:15

Boswell, post: 453423, member: 29034 wrote: Edit: Sorry, I just realised your interface is FireWire and not USB. Scrub the second option. I'll leave the reference there because it may be useful to others who have a USB audio interface.

Yes. I am searching for a low cost firewire isolator to get rid of this.

The other solution I tried is just wrap around one XLR pin (either interface side or mic side) with a copper wire and connect the other end to the ground. this gave me little noise reduction but not completely.

As you suggested, let me search for other power supply adaptor too.