Strange buzzing noise coming from mic setup, help needed; details inside

K

KKristophDavion

New member
Hi Everyone,

I've actually just stopped lurking to create a post on this issue.
Currently, I have a setup at home which consists of 2 Mikrotek-Gefell M70 microphones I got as a gift in a left-right stereo recording setup, going into a Harbinger L802 board with PP, out through main mix using 1/4" to RCA adapters going and compressing into a mono input through a 1/8" jack in my PC. Granted, yes. This is a bit of a janky set up but the mixer is much more useful to me than the Art Dual USB preamp would have been as I can take the mixer around to gigs elsewhere.

Recently, however, I've been getting a strange beeping and buzzing noise in the background of my raw recordings. It's something I can remove through the noise removal tool in Audacity, but it's something that I would like to eliminate completely if possible. I've included links below to a broad picture of the setup I am using and a 5 second damp raw recording of what is coming through my mics as of now.

My current suspicions stem from bad cabling, either due to the multiple adapters I am running through or the fact that the M70s use an outdated 7-pin XLR connection, which is going through one of Geffel's 7 to 3 pin cables. All else fails, I can check different 7 pin cables and a different mixer, as I still have waranty for my mixer.

I just wanted to see if I could get a second opinion before I did anything as rash as replacing perfectly working hardware

Thanks,
-K. Davion

Imgur: The most awesome images on the Internet
https://youtu.be/6IgliKkSy90
 
It sounds like computer noise. Does moving the mouse around have an effect on the noise?

Have you tried using the Art, and does the same noise occur?

In any case, I'd be inclined to use the Art rather than the Harbinger, because its USB deliver to the PC is likely to give better quality than the line out from Harbinger via adapters to audio input on the PC.
 
The noise seems to come out regardless of how much the mics are outputting through the system, so I'm inclined to believe that it is not an issue on that end

As for using a USB preamp, that will have to wait until after the weekend unfortunately as I have lent my art dualamp to a friend for the weekend. During the time I will also try to find a better setup for outputting from the harbinger as the rca output is actually somewhat offputting.

Will report back if there's anything to report

Thanks!
-K. Davion
 
This is completely silly. You have two classic, sought after, expensive, high quality mics and you are running them through an ultra basic level mixer into a 3.5mm $10 quality audio chip in your PC?

First thing is that those mics are likely to be taking the phantom power from your mixer - two of them running virtually the full current demand phantom can cope with probably means the 48V rail will be low, adding noise to the mic preamps inside, which can also expose the system to computer noise. Going up in level in the cheap mixer, then reducing it a bit in the computer interfacing exposes the system pretty badly. Decent mics, and mains powered equipment plugged into computers is an everyday noise problem. Balanced mics, but then unbalanced connections to the computer make nasty noises inevitable. Even a cheap USB interface will help no end. Use the mixer for outputs and other stuff - but get rid of it from the input chain. Bearing in mind how much you could get for the mics, you could sell them and buy a much better system with loads of nice sounding mics.

You have a Range Rover with leather seats, and all the gizmos running on second hand tyres, with no tread and rusty rims.
 
Thank you for the scathing regards

The mics were a gift from my late uncle so by no means am I selling them off to buy other equipment

As for the input chain that is next on my list of things to resolve, I regret buying a mixer without an xlr output but there is little I can do about that for now

Also, I'm not entirely sure that you read my second post about the fact that the noise still appears even with no inputs plugged into the mixer, and the PP turned off; this leads me to believe that it is either an issue with the mixer or with the outputting connection

I understand that I am severely underutilizing the capacity of the mics but that's not the issue I came to solve, and I would appreciate less candor when it comes to the use of my equipment

Regards,
-K. Davion
 
I discovered that both my Internet modem and my WIFI hub produce a lot of background static. This includes a pulsating bit of static. I'm at the point that I'm going to get a 30' coaxial extension and put the darned things in another room. Hope you can track down the source of the static.
 
I believe you may be on to something

I had just done a recording in a different room using my laptop and there was no noise to be heard. This means that either I'm getting background static from my all the wireless drives around my computer or the computer itself. As for now, if I have to record I will be moving my gear over to do so

Thanks,
-K. Davion
 
You're using an unbalanced input so the environment is a huge factor. This makes sense. ^^
Pretty much anything in the area could cause hums and buzzes. Transformer, light dimmers, motors, AC...all sorts of things.
 
KKristophDavion said:
I believe you may be on to something

I had just done a recording in a different room using my laptop and there was no noise to be heard. This means that either I'm getting background static from my all the wireless drives around my computer or the computer itself. As for now, if I have to record I will be moving my gear over to do so

Thanks,
-K. Davion
Click to expand...

Before I discovered the source of my problem, I was prepared to attach everything to my Mac laptop (solid state drive rather than hard drive) and then shut off all power to my house. While it would mean I had to reset all of my clocks, in this area of the country power outages are commonplace.
 
JefferySmith said:
Before I discovered the source of my problem, I was prepared to attach everything to my Mac laptop (solid state drive rather than hard drive) and then shut off all power to my house. While it would mean I had to reset all of my clocks, in this area of the country power outages are commonplace.
Click to expand...

Actually, I had just moved everything back to its normal positions and tested with my laptop in my living room and there was no background noise. Changing the output back to my desktop seemed to have brought back the issue

I can only assume this means I need to fix some hardware somewhere

Whether this means it's a grounding issue from my desktop or if I need a new sound card is yet to be determined
Thank you for your help however,

Regards,
-K. Davion
 
I have to agree with rob's sentiments. World-class microphones in stereo, summed to a mono signal and sent through a PC sound chip is pretty terrible all-around. Between the potential phase issues of summing 2 mics to mono, and the inherent awfulness of an integrated PC sound chip and its connectors, it's no wonder there is all sorts of noise in your signal. Even a cheap little Behringer UCA222 for $30 would be a pretty big improvement, even though it still uses noise-prone RCA connectors. I'd really recommend looking into 2-input audio interface, something like the Focusrite Scarlett 2i2, Steinberg UR22, PreSonus Audiobox 22, or countless other entry-level audio interfaces in the sub-$200 range. Any of those will be worlds better than the mixer->string of adapters->integrated PC audio chain.
 
Tadpui said:
I have to agree with rob's sentiments. World-class microphones in stereo, summed to a mono signal and sent through a PC sound chip is pretty terrible all-around. Between the potential phase issues of summing 2 mics to mono, and the inherent awfulness of an integrated PC sound chip and its connectors, it's no wonder there is all sorts of noise in your signal. Even a cheap little Behringer UCA222 for $30 would be a pretty big improvement, even though it still uses noise-prone RCA connectors. I'd really recommend looking into 2-input audio interface, something like the Focusrite Scarlett 2i2, Steinberg UR22, PreSonus Audiobox 22, or countless other entry-level audio interfaces in the sub-$200 range. Any of those will be worlds better than the mixer->string of adapters->integrated PC audio chain.
Click to expand...

Thank you, I had actually completely forgotten about using audio interfaces so all in all that would probably be my best solution.

As for now, I can probably bring my mixer around for other design gigs I'll have but I'll pick up a Scarlett 2i2 for at home work

Many thanks,
-Kay Davion
 
How are you listening to this?

I'm assuming on the input side:

1 mikes > mixer > laptop (no noise)
2 mikes > mixer >desktop (noise)

But what comes after the computer?

Is it, for example, laptop > mixer > speakers?
Or maybe laptop > internal laptop speakers?

and what about the desktop?
And have you tried the Art in place of the mixer?

Or what?
 
You must log in or register to reply here.
Back
Top