I’ve been using Audacity with my Blue Yeti Pro mic for a few years now.
In my audio recordings, I often get an intermittent background noise under the same recording conditions with the mic open, which is difficult to get rid of and impossible to predict. Even when I do the recording on the same day - one segment is clear and the next could have this noise.
My first question is - could someone offer an insight whether this is a mic OR Audacity related issue?
On the mic, I have a very small dB gain - and still need to speak very close to the mic, so can’t reduce it to zero or to the negative setting.
and two - when I tried to fix the voice track with the Noise Reduction feature in Audacity - I quickly abandoned it as even a small fix significantly reduces the dB loudness of the voice recording - which I need to put in a lot of effort to anyway, to have it at the right level.
I would be grateful for any insight and hopefully a solution.
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Sounds like you are doing everything right, but I agree that the background noise is a bit high.
Audacity does (intentionally) add a little bit of noise to exported tracks. This is called “dither noise”, and it (surprisingly) improves the dynamic range of the recording by preventing “quantization noise”. The first half second of your audio clip has this “dither noise”, which I think you will agree is quiet enough to not be a problem.
The noise that starts at about 0.8 seconds into the clip, sounds like “pre-amp noise”. For USB microphones, the pre-amp is built into the mic. It doesn’t look or sound to me like something that could be coming from Audacity.
That’s a bit worrying. Being intermittent suggests that it may be a hardware fault.
Does the problem come and go during a recording, or is it that one day the noise is there and the next day it isn’t?
It could be something as simple as dirty or worn contacts in the microphone’s input level control, in which case you may just need to turn that control up and down a few times to “clean” the contacts. If this is the problem, then it could be a sign that the mic is on its way out.
Or are you talking about that little boost in noise at the seven second mark? In any event, I have been able to get significant improvement by applying the rumble filter and noise reduction. Attached.
I think the background noise is from a motor, air conditioner, heater or other noisemaker in the room with you. You also have contradictory conditions. You claim a business in Australia, but there is a significant portion of the noise at 120Hz which is a signature of recording in the US or other 60 Hz power country.
Are you recording in the US?
I got your noise improvement by Effect > Equalization: Low Rolloff for Speech, Length about 5000; followed by Noise Reduction 9, 6, 6. Neither of those affects your voice quality.
If you listen very carefully, does your computer fan go on and off on occasion? Once you identify room noises, it’s something of a zoo to figure out where it’s coming from.
If you’re close-talking to the Yeti Pro and you’re reading from the computer screen, that means everything is scrunched together in a very small spot. I have a laptop that switches the fan on and off and the only way I knew it was happening was I pushed my ear up to the hinge once when it was running. It’s behind the ESC key upper left.
Do you have a tablet to use for reading or can you print the scrips and read it that way? Stretch the USB cable out to its max length (do not extend it) and put a pillow or towel rolled up between the machine and the microphone.
Also I use a heavy blanket over the whole desk for noise abatement.
I’m in Melbourne Australia. I live here and I record here. Mains voltage in Australia is 230V 50Hz if that’s what you are referring to.
My PC fan is a good tip, I will investigate it. I have a large column which could get noisy. What happens is that on one day, I could be recording various segments of the same production in time intervals, say one in the morning - and it is clear, and then the next few hours later - and lo and behold there is noise. I also need to check my fridge as the low hum which is not very audible could be recoded by the mic.
If there is no ambient noise in the room, I would expect no detectable difference between mic off and mic on.
I will keep testing and will try your suggested fixes.
PS I understand re post moderation. No hurt feelings
re cardioid configuration - that’s exactly what I do. Please see the photo. During the recording, I pull the mic closer to me,so it’s about 50-60 cm from the tower facing it with its dead spot.
I still think that’s my PC fan…will need to test. I also like your idea of a blanket
BTW I notice on your both photos you use a screen pop filters. I was initially using a screen one but found it too clunky and obstructing my view, so switched to a socket. Which one in your view is better for noise reduction?
Which one in your view is better for noise reduction?
Neither one if I understand you’re meaning. The purpose of both is to prevent large, slow movements of air typical of P popping or wind noise. They are both intended to be acoustically transparent while they’re doing it.
The tennis racket does it through the limited ability to stretch. There’s a second type which is a solid screen.
That one works by the inability to pass wind through its little holes. Neither is good for field work where wind can come from any direction. There, the foam ball or other covering reins.
The foam ball can indirectly affect motor noise. It will allow you to get closer to the microphone without distortion. You got louder but the motor didn’t. It’s not filtering out the motor.
You can use the microphone to help you find the noise. Take it from its mount, remove the foam and start a recording. Turn it so it faces different parts of the room, announce as you go.
“This is pointed to the fridge.”
The USB cable is going to restrict your ability to move around. I did it with a conventional microphone and a long cable. A piece of my musical keyboard across the room was making hummmmm noise.
You can also do it in real time by listening to the system while you go. That can be really fast because you don’t have to stop and play the recording.
Not having good soundproofing can cause problems.
“This is the fridge noise bouncing from the hard walls.”
I also would like to add that I run my podcast audios through Auphonic - an excellent online levelling service, which includes noise reduction. However, once I have mixed my voice with music to one mp3 file, even the Auphonic’s algorythm can’t remove the noise embedded in the mic input.
If you’d like to hear the finished product to spot the difference, please visit my website https://www.quantumliving.com.au/podcasts and listen to the episode QL015 (New Year New You Part 2). The first segment is clear, the second one which starts at 14’05" still has some audible noise to my chagrin - I took the clip from there. (and if you like my podcast - subscribe and enjoy! it’s free! )
of course. I have 2 USB ports at the front of my PC column.
in one, I had my mic plugged in and in the second one…I had my external hard drive… - you can see it on the photo…and when just now Audacity crashed (yeap), I removed BOTH cables and then it hit me…- IT WAS THE HARD DRIVE MAKING THIS HUMMING NOISE!!
I quickly did a test recording without it being plugged in - and THE NOISE IS GONE!!!
I used to have this hard drive plugged in or not - and did not correlate this with the recordings until now…
so - for anyone out there having some strange background noise - unplug any other devices you don’t use for the recording from your computer…