Squealing noise from microphone

  • Thread starter Thread starter Lego
  • Start date Start date
L

Lego

New member
Hello to everybody

This is my setup:
Lexicon Alpha
Win 7 64BIT

Behringer C-1

External phantom power suypply SOUNDKING EE301

I use AUDACITY

When i connect everything and put my headphones to MONITOR output of Lexicon. i hear terrible squeeling noise.
It is there no matter what i do or change, when recording. I am clueless.

I recorded the noise so you can listen to it: ht tp://vocaroo.com/i/s1XZzL9KT5w5 (please delete space between ht and tp)


Do anybody has ideas how to solve this issue? Its impossible to reduce from the side of software.

Thank you for any ideas.
 
Where does Audacity think it's outputting the sound to?

The squealing is in the headphones, yes? Not anywhere else?

Do you have external monitors and are they on?

Does it still squeal when you move the microphone further away from all your gear? Like 5 metres away...
 
I have headphones connected to MONITOR output (jack) of the Lexicon Alpha. And there i can hear the squeal. But also when i record something, the squeal is still there, so it cannot be only faulty HW monitoring output on Lexicon (which was my first tip).

I moved microphone 4 meters away from all equipment - no change. then i moved Lexicon 2 meters away from PC and from microphone with phantom supply, no change.
I thought that phantom supply can be the generator of the noise, so i put long XLR cable from supply output to behringer microphone, there was 4 meters distance, and the noise is still there. Cable is D'adario with lifetime warranty so i do not believe that its faulty.
second cable - from lexicon to phantom supply is shorter, but i switched them to make both test and no change. I am starting to be hopeless. What else to check?

So to answer directly:

1. In the headphones in monitor output, but after recording also in the record. should i try different output?
2. i have headphones connected to MONITOR output from Lexicon (Should i try another output? but still i will need monitors)
3. Yes squealing is there when i move mic away from device
 
That's not a squeal! It's very common, low level processor noise generated inside your computer, and common virtually all internal sound cards designed to maybe do a bit of Skype, and be bellowed into. The problem is that it shouldn't be getting in if you are using the Lexicon - however, my friend has this setup, and routes his computer sound card output back into the lexicon with a cable from the 3.5mm headphone output. You've not got this cable attached have you? Pulling this cable out on his removes the noise. Using just the USB to the computer works brilliantly for recording work, but he uses the cable from the headphone socket so he can play a CD through the Lexicon, then into his audio system. Have a look at your setup and if this cable is present - pull it out and I bet the noise vanishes.
 
I think I do not have this cable connected:

Here is my setup:

PC USB socket <---- USB CABLE -----> Lexicon ALPHA
Lexicon ALPHA microphone output(XLR) <---- XLR cable ----> Soundking Phantom power supply <---- XLR cable ----> Behringer microphone

Lexicon ALPHA monitor JACK output <---- 3.5mm JACK cable Headphones AKG

So I have no sound connection between Lexicon and PC.
 
That's not good then. The lexicon allows you to monitor the inputs on the headphones, so the first thing to do is disconnect the computer. If the signal becomes clean, then the interference is getting from the computer to the lexicon down the USB cable. This is a bit unusual, but worth trying a different cable in case the screening is the problem?
 
Remove power from the phantom power supply. Do you still have the noise?
Unplug the mic and phantom power supply from the Lexicon. Do you still have the noise?
Can you plug the lexicon into another computer? Do you still have the noise?
Can you use a different mic? Preferably a dynamic mic. Do you still have the noise?
Do you have a guitar you could plug into the Instrument jack? Do you still have the noise?
 
Chilli, I unplugged the 230V imput to Phantom supplier - there was still some energy in microphone (thanks to the condensator) and the noise dissapeared!!! i almost fall down from the chair :D

So the phantom supplier is the generator maybe, i have to buy different one to test it.

After that i will tell you the result i hopefully there will be no other things to investigate
 
Get rid of the phantom power supply and the Lexicon and get an audio interface its own phantom power.
 
mjbphotos said:
Get rid of the phantom power supply and the Lexicon and get an audio interface its own phantom power.
Click to expand...

Yeah it's time to invest in something that has phantom power and stop adding more machinery to the vocal chain. More stuff = more problems.
 
Whilst I agree that an integrated solution, AI+spook juice, IS the best way I am not totally convinced that the 48V supply is the prime cause of the noise.

You can make a "perfect" phantom supply with 5 PP3 batteries in series, for such a test they can be really cheap, RockBottom crap since you only need the power for a few minutes and not a lot of it at that.

As ever, check the record level settings in Win 7.

Dave.
 
Hi to all!

So i changed phantom supply to a different one (Behringer model) and the squealing noise is gone! now its completely clear.
thank you all for a help!
 
You must log in or register to reply here.
Back
Top