Microphone Ground Loop Problem

F

fingerdance

New member
Hi, I have a new microphone and it has a electrical buzzing sound when i try to record using it. It is not the soft buzzing sound that can be removed, after searching up about it i realised that it should be the cause of ground loop. So i decided to buy a ground loop insolator for the problem but it still doesnt help. Does anyone have any experience or any idea to solve this?

Im using a laptop, a condenser microphone with 3.5mm head, i attach it to a usb sound card for the usb input, and a ground loop insolator.(Note. when i link the ground loop insolator the microphone isnt picking up any sound)
I suspect its the problem of the usb sound card because if i record without the microphone plugged to the sound card it still has the sound.
Thanks for helping :)
 
Hang on - if you record WITHOUT the mic plugged in, you still hear the buzz? Then it's nothing to do with the mic, is it!

I'm stuck on the rest - a condenser mic with a 3.5mm lead, not head???? Well - if the condenser needs power, the 3.5mm connector isn't going to work. You have a USB sound card? One with an XLR socket for the mic, I assume?

I'd guess the buzz you are getting is not anything to do with a ground loop which is a 50Hz (UK) or 60Hz (US) plain and simple hum. If you are describing a sound with sort of 'movement' in it, rich in harmonics, then it's probably buss noise. If we can hear a sample it's simple to identify. Some audio interfaces do this with some computers and it propagates along the USB cable between computer and interface. Often the unit draws it's power from the USB line, rather than a proper power supply, and some USB sockets just cannot supply enough current, so the voltage drops and the thing because unstable. My friend had this with a Scarlett - usually a good interface, but his computer just hated it. Swapping to a different brand cured it for him. Do you want to post a sample?
 
It can't be a ground loop. That requires two different devices whose grounds are connected together two or more different ways. You don't have that.

It could be a poor or broken ground connection somewhere along the way. It could be a "dirty ground" or just a noisy power supply in general. I suspect most of the problem is cheap consumer-grade equipment operated by an ametuer who doesn't fully understand the situation.
 
fingerdance said:
Hi, I have a new microphone and it has a electrical buzzing sound when i try to record using it. It is not the soft buzzing sound that can be removed, after searching up about it i realised that it should be the cause of ground loop. So i decided to buy a ground loop insolator for the problem but it still doesnt help. Does anyone have any experience or any idea to solve this?

Im using a laptop, a condenser microphone with 3.5mm head, i attach it to a usb sound card for the usb input, and a ground loop insolator.(Note. when i link the ground loop insolator the microphone isnt picking up any sound)
I suspect its the problem of the usb sound card because if i record without the microphone plugged to the sound card it still has the sound.
Thanks for helping :)
Click to expand...

Most laptop power supplies are battery chargers and will inject ripple noise on the ground. The to see if this is going on with your laptop, the buzz will go away when the power cord is unplugged.

a real interface wouldn't help you here either, unless its an isolated connection like Dante (which an ethernet is one of the only isolated I/Os those computers have) .
 
fingerdance said:
Im using a laptop, a condenser microphone with 3.5mm head, i attach it to a usb sound card for the usb input
Click to expand...

What model is the microphone, USB Soundcard, and any other pieces of hardware in the chain?

The best approach is probably to use a microphone which requires 48V phantom power over XLR, and an audio interface with mic preamp which can provide that. (or a USB microphone)
Alternatives may work but a: they're probably not ideal and b: we'd need specifics.

You can try the whole setup on a desktop computer to rule out (very real) laptop power supply related issues,
but where 3.5mm jacks and condenser microphones meet, full details are required.
 
rob aylestone said:
Hang on - if you record WITHOUT the mic plugged in, you still hear the buzz? Then it's nothing to do with the mic, is it!

I'm stuck on the rest - a condenser mic with a 3.5mm lead, not head???? Well - if the condenser needs power, the 3.5mm connector isn't going to work. You have a USB sound card? One with an XLR socket for the mic, I assume?

I'd guess the buzz you are getting is not anything to do with a ground loop which is a 50Hz (UK) or 60Hz (US) plain and simple hum. If you are describing a sound with sort of 'movement' in it, rich in harmonics, then it's probably buss noise. If we can hear a sample it's simple to identify. Some audio interfaces do this with some computers and it propagates along the USB cable between computer and interface. Often the unit draws it's power from the USB line, rather than a proper power supply, and some USB sockets just cannot supply enough current, so the voltage drops and the thing because unstable. My friend had this with a Scarlett - usually a good interface, but his computer just hated it. Swapping to a different brand cured it for him. Do you want to post a sample?
Click to expand...

Yes,after experimenting with it a few times I would say its not the problem of the microphone. But I don't know what is it.
and I wrote head. yes, i do have a usb card, it connects the 3.5mm head from the microphone to the sound card, and the sound card has usb head to the usb port of my laptop. Voice Sample - vocaroo.com/i/s0O7RUH8Tmgb
 
ashcat_lt said:
It can't be a ground loop. That requires two different devices whose grounds are connected together two or more different ways. You don't have that.

It could be a poor or broken ground connection somewhere along the way. It could be a "dirty ground" or just a noisy power supply in general. I suspect most of the problem is cheap consumer-grade equipment operated by an ametuer who doesn't fully understand the situation.
Click to expand...

Forgive my lack of information. Because I searched up about the problem and i found that my problem is most similar to it. Here is the noise to check. I wonder what i can do to solve such problem?
vocaroo.com/i/s0O7RUH8Tmgb
 
drtechno said:
Most laptop power supplies are battery chargers and will inject ripple noise on the ground. The to see if this is going on with your laptop, the buzz will go away when the power cord is unplugged.

a real interface wouldn't help you here either, unless its an isolated connection like Dante (which an ethernet is one of the only isolated I/Os those computers have) .
Click to expand...

Yes I have tried to unplug my laptop but the sound still exist.

Steenamaroo said:
What model is the microphone, USB Soundcard, and any other pieces of hardware in the chain?

The best approach is probably to use a microphone which requires 48V phantom power over XLR, and an audio interface with mic preamp which can provide that. (or a USB microphone)
Alternatives may work but a: they're probably not ideal and b: we'd need specifics.

You can try the whole setup on a desktop computer to rule out (very real) laptop power supply related issues,
but where 3.5mm jacks and condenser microphones meet, full details are required.
Click to expand...

I see. I guess I can only work with what I have now but thanks :)
 
I am going to guess you have one of the $20 US (ish) 'BM-800' type microphones that are flooding the market right now. They have various model numbers but seem to be of the same basic construction. They use an 'Electret' self polarized capacitor capsule and an impedance converter (amplifier) powered from the 3.5mm TRS jack found on most laptops. You do not need any other interface with these mics.

However! The QC on these microphones seems to be poor to bloody terrible and many either don't work at all or have low, hissy outputs.

Post the model of the mic and a link to where it came from. WHEN they work, as mine did, they are really quite good. Astonishing in fact at the price!

Dave.
 
ecc83 said:
I am going to guess you have one of the $20 US (ish) 'BM-800' type microphones that are flooding the market right now. They have various model numbers but seem to be of the same basic construction. They use an 'Electret' self polarized capacitor capsule and an impedance converter (amplifier) powered from the 3.5mm TRS jack found on most laptops. You do not need any other interface with these mics.

However! The QC on these microphones seems to be poor to bloody terrible and many either don't work at all or have low, hissy outputs.

Post the model of the mic and a link to where it came from. WHEN they work, as mine did, they are really quite good. Astonishing in fact at the price!

Dave.
Click to expand...

Yeap, you are right. The common BM800s. You are right again, because I actually did a little research about this and found that these microphones actually doesn't need any interfaces to be used, of course it would be better with one but I've seen many are just as good without although I have a USB Sound Card to just enhance it a little more. That's why I'm a little disappointed that it didn't work for me.

I would say in this case its not the microphone's problem as I still pickup the 'groundloop' buzzing sounds even if i record w/o my microphone and w/ the usb sound card plugged into my laptop only, of course the laptop won't pickup any recordings except the buzz.

I'm afraid i couldn't give you the model as it isn't in any of the boxes or microphone itself but here it the link
11street.my/productdetail/bm-800-studio-live-streaming-broadcasting-45527290

Steenamaroo said:
You could give us the details....?
Now Dave's having to guess what you've got. ;)
Click to expand...

Yes I hope I answered them.
 
fingerdance,

Does your 'USB sound card' in any way look like this one in this image from another HR thread...

22070202_1544721922251360_2048453917_o.jpg

If it does, the quality may not be too good and that could be the problem with the hum/noise you get. It may not be designed to power the BM800 properly either.
 
The op stated earlier that the sound card records bad when nothing is connected. That points towards a bad sound card, but the op could be boosting the gain too much and recording that. These mics don't work very well on electrect phantom voltage(3-5v). They work good on lapel phantom voltage (9V-12V) and standard P48 (48V) .

Some sound cards have 3-5V and others have 9-12V for mic power.

So just because you got an XLR to 3.5mm cord with it doesn’t mean its going to work with your equipment properly.

A standard interface that will work for it is not that expensive.
 
drtechno said:
The op stated earlier that the sound card records bad when nothing is connected. That points towards a bad sound card, but the op could be boosting the gain too much and recording that. These mics don't work very well on electrect phantom voltage(3-5v). They work good on lapel phantom voltage (9V-12V) and standard P48 (48V) .

Some sound cards have 3-5V and others have 9-12V for mic power.

So just because you got an XLR to 3.5mm cord with it doesn’t mean its going to work with your equipment properly.

A standard interface that will work for it is not that expensive.
Click to expand...

These things seem so variable D' that results cannot be determined with any accuracy. Mine worked AS well on the 5V from this i3 HP laptop as it did from 48V on XLR from an AI.

I agree that Windows needs its internal gain setting to optimize noise. The default for "External Microphone" is 100% and that is too high for most. When a generic USB interface is used, gain needs to be set to 5% or less. Best of course to use an AI that is 24 bits and has decent ASIO drivers. And that of course is by far the OP's best course of action, an interface.

The best value one I have tried is the Alesis i02 Express although the Behringers seem to get a decent rep. WHATEVER you do, do not go super cheap and buy an AI with only ONE XLR input! If you are at all into recording music, building songs etc, get stereo capability.

Dave.
 
fingerdance said:
I suspect its the problem of the usb sound card because if i record without the microphone plugged to the sound card it still has the sound. Thanks for helping :)
Click to expand...

Have you tried plugging in your mic straight into your computer mic input jack? If so, make sure you adjust your mic input level as described by others to the lowest setting that will allow the mic to work. According to all the links you have provided, this is what your mic is designed to be used with. Depending on the quality of your internal sound card, will determine the quality of your recording. Cheap sound card = bad recordings.

After listening to your audio link, that is the same noise people get when they do a mix minus using Skype. Again, this situation is also due to the quality of the sound card, the only difference is they are using their headphone out jack as well as their mic input jack.
 
Couple of pikkies in case you were wondering?
Dave.
 

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