Clip advice

Narrating and Producing Audiobooks.

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Clip advice

Permanent link to this post Posted by sartre245 » Wed Mar 08, 2017 11:09 pm

Hello,

I am quite new to the sound world and have untrained ears and technique. I am just trying to produce a decent narration.

I have the USB CAD u37 mic. It seems that the mic itself creates a sine-wave type whine that is, very roughly, around 3220 hz.

This mic records quite low so if I amplify to normal levels this whine becomes even more pronounced, and you can hear it through the reading, not just room noise.

It doesn't seem to be electronics or lights in the room, but I don't know this for absolutely certain until I take my mic setup around the house (laptop, side arm stand, 6" pop filter, and aforementioned USB mic). Planning to do that.

Right now I am trying to approach this whine with a notch filter, but since 3220 hz is of course in voice range it makes a big change. But, this change is less unpleasant to the ear than overprocessing with noise reduction.

Still trying to figure out how to make the most of my setup. My guess is that other inexpensive USB mics may also have this sine-wave style interference issue.

Any thoughts on this, like the forum itself, will definitely help me learn a bit more and are appreciated!

audac-forum.wav
unprocessed sample
(1.89 MiB) Downloaded 11 times
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Re: Clip advice

Permanent link to this post Posted by Trebor » Thu Mar 09, 2017 4:55 am

sartre245 wrote: ...I have the USB CAD u37 mic. It seems that the mic itself creates a sine-wave type whine that is, very roughly, around 3220 hz ...
Right now I am trying to approach this whine with a notch filter, but since 3220 hz is of course in voice range it makes a big change. But, this change is less unpleasant to the ear than overprocessing with noise reduction.

A notch filter at 3100Hz @ q=50, gets rid of most of the artifact on the sample you posted ...

Spectrogram of ''audac-forum'', Before-After notch 3100Hz q=50.png
Spectrogram of ''audac-forum'', Before-After notch 3100Hz q=50.png (346.37 KiB) Viewed 138 times

but the whine is not a constant frequency.

To avoid the artifact being created, try other sample rates in Audacity when you record, e.g. 48000Hz / 32000Hz , rather than the default setting of 44100Hz. [No guarantee that will work , but worth a try].
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Re: Clip advice

Permanent link to this post Posted by sartre245 » Thu Mar 09, 2017 9:56 pm

Oh, nice. I am going to try this tonight, thank you, it would be just fantastic if this dropped out! Thanks also for the notch suggestions.
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Re: Clip advice

Permanent link to this post Posted by Trebor » Thu Mar 09, 2017 10:49 pm

The only other suggestion to avoid the artifact noise would be changing the audio driver (software) for your version of Windows :
either updating to the latest version, or rolling back an (automatic) driver update to an older version , (and stopping it automatically updating).

Updating other drivers may also be worth a try, e.g. I had a WiFi driver which caused audio to glitch at regular intervals, when I updated the WiFi driver the audio glitch was gone.

Set a restore-point before changing drivers so you can easily revert back to your current state if things go pear-shaped.

https://www.howtogeek.com/using-windows-system-restore/
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Re: Clip advice

Permanent link to this post Posted by sartre245 » Fri Mar 10, 2017 5:34 pm

So, I have tried all these suggestions, which were great. and actually had one audio driver update, which I don't think has ever happened before (the message "your drivers are up to date" have been eternally consistent until now).

I also took the mic from room to room and floor to floor and also through a few laptops. This noise persists in every location but varies in Hz and sound with different laptops and USB ports, although it never goes away.

My working theory at this point is that it is a conflict with the laptop's power supply. As mentioned, the whine comes up a little differently with different USB ports, but it is worst on the one on the side of the power supply. If I remove the charger/ adapter from the laptop, the problem doesn't disappear, but is noticeably softer.

I read that a self-powered USB hub may help this problem, so I ordered one and will try it out.

Thank you again so much for the help in narrowing down this problem. It helps so much to get an idea of what to look for.
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Re: Clip advice

Permanent link to this post Posted by kozikowski » Fri Mar 10, 2017 5:58 pm

I was about to say there was another recent poster with USB CAD u37 trouble...but that was you.

You might pick a demarcation point or date when you officially give up. I mean a real date like in two or three months. If you don't, we could be here for a while. There is no shortage of people having noise problems with modest cost USB microphones.

One of the ways manufacturers bring the cost down is by leaving out the parts that suppress noise—the power supply filtering. That's expensive. So many of the microphones in this group are sensitive to USB noise, computer connection noises, power supply problems and other instabilities. Higher end microphones and interfaces just don't have these problems (they can have other problems).

Oddly, your noises are different from The Yeti Curse. We know what that is. That's data signaling leaking into the USB 5 volts. But that doesn't change over time and yours moves around. So that is a puzzlement.

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Re: Clip advice

Permanent link to this post Posted by kozikowski » Fri Mar 10, 2017 6:02 pm

We used to recommend that wall-powered USB Hub thing as a universal Get Out Of Jail card until one poster found one so cheap it created its own noise.

Nobody wins.

Remember if you do try that, you can't use the hub for anything else. If you plug anything else in, your sound will immediately have ticks and holes in it as the hub tries to quickly switch between jobs.

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Re: Clip advice

Permanent link to this post Posted by sartre245 » Fri Mar 10, 2017 6:10 pm

Thank you for the insight on the hub, Koz. That is great to know.

You are right about a give-up date. I almost pulled the trigger on a blue yeti this week, but I felt I wasn't ready since I didn't understand anything about the nature of the problem with my existing USB mic. I actually like this mic just fine except for that possible isolation problem. The sound is quite decent otherwise.

But if there is no good solution to this I will definitely buy a more expensive one, but hopefully knowing what pitfalls may come with that one also and some workarounds for it.

In the meantime I greatly appreciate the insight here.
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Re: Clip advice

Permanent link to this post Posted by kozikowski » Fri Mar 10, 2017 6:26 pm

Blue Yeti Pro.

https://www.sweetwater.com/store/detail/YetiProStu

Regular Blue Yetis can have that frying mosquito noise problem. That's where my phrase "Yeti Curse" comes from.

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