Microphone picking up neighbor's AC

Special Interest Groups Audiobook Production
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It’s wonderful to hear that, and I believe I can handle all the steps you’ve listed when it comes to mastering. (With my older version of Audacity, Nyquist Prompt didn’t seem like it was doing anything when I used the code you provided in your guide, but I haven’t tried in the newer version - an aside, we can come back to this).

It’s good to know I can cross more or less the biggest hurdle, but, maybe I should give you a sample of me reading with that devilish humming - you knew we’d be back here. I can do what you’ve shown me through mimicry, not knowledge, but I feel knowledge is what I’ll need to render any recordings with the humming workable. As it comes and goes, I don’t know how to tackle it. If it were constant, I feel it’d be simpler. What do you think?

Edit: Here’s a query for you: what’s going on in this recording? I just popped in to do another recording for the fun of it, and I noticed something veeeery wrong. Here’s a sample of it.

It’s happening on the cardioid setting of the Snowball mic, and not on setting 3. I didn’t try 2.

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There appears to be a slight difference there, but not really better or worse. The 60 Hz hum is a fraction louder and the 120 Hz hum is a fraction quieter.

One thing that is puzzling me is that mains hum is usually at a very precise frequency, either 50 Hz or 60 Hz depending on country. In your samples, the hum appears to be around 59.2 Hz, but the first “harmonic” is almost dead on 120 Hz. Is there something unusual about your mains supply?

This code, run in the Nyquist Prompt, will filter out the hum, though personally I think the hum is a low enough level (after running Koz’s “mastering” process) to not be a problem. So it’s up to you - if the hum is annoying you, then this should remove it:

;version 4
(notch2 
  (notch2 *track* 120 60)
  59.2 16)
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One thing that is puzzling me is that mains hum is usually at a very precise frequency, either 50 Hz or 60 Hz depending on country. In your samples, the hum appears to be around 59.2 Hz, but the first “harmonic” is almost dead on 120 Hz. Is there something unusual about your mains supply?



It’s happening on the cardioid setting of the Snowball mic, and not on setting 3. I didn’t try 2.

You may be one of those lucky dogs with two different problems.

Position 1 of the switch records sound mainly from the front of the microphone—speaking into the Blue name.

Position 3 of the switch records all around. Doesn’t matter if you’re in front or not.

Position 2 is for very high volume performances such as playing a trumpet into the microphone. It knocks the sensitivity of the microphone down so it doesn’t overload and damage the sound.

You have two different hums. The one that’s not quite 60 may be coming from a motor or cooling fan. They run at any speed, but they like snuggling up to about 60. The 120 is coming from the house power system. That one has to be spot on accurate for the power company to share power across the state. Since the two sounds didn’t change the same way when you changed the microphone, you very probably have two different problems.


There is a simple solution, but it’s not elegant. If you make it out to two weeks of not being able to record well on the computer, stop using the computer.


H1nTechnicalSetup.jpg
That’s a stand-alone sound recorder. Using exactly what you see there, I produced an ACX quality sound clip after simple mastering. No noise reduction needed. That’s a photo illustration. Substitute my quiet third bedroom for the wood. Everything else is the same. That’s the exact script I read.



Koz

44

Position 1 of the switch records sound mainly from the front of the microphone—speaking into the Blue name.

Sorry to sound obtuse, but does any of that necessarily explain why after unplugging and re-plugging the Snowball, settings 1 and 2 seem broken? I read last night about people experiencing a high pitched “whine” with the Snowball, though I’m not sure if my symptoms are completely in line with what everyone else experienced.

You’ve got an amazing voice by the way, Koz.

I have no issues recording on setting 3 if I must - my first ACX project is passing checks and being approved entirely in setting 3. The “Tyrion” sample I read you last night was my first recording I’ve ever attempted on setting 1. I liked how it turned out, and any ambient noise reduction would be great for my particular problem. So I’d like to figure out what changed in the 30 minutes I had the mic unplugged and tried to record again.

As of this morning, settings 1 and 2 are still producing a high-pitched whine, regardless whether or not the laptop is plugged in to the mains. It produces this whine on two different computers.

Speaking of the mains, the only hum that concerns me is the very obvious ac humming. And to answer Steve’s question, I’ve often noticed weird power issues in the apartment, and we recently had a breaker replaced. Suffice to say I’ll be recording on battery power nearly 100% of the time, and the ac hum is really the only problematic issue, in my view. I may sound crazy beating this issue in to the ground, but I’m confident that’s what the loud hum is, and I’ve even gone and looked at my neighbor’s ac units around when it starts and confirmed it’s them. This sound reverberates throughout my entire apartment and is undeniable.

I noticed you provided a Nyquist code while referencing the mastering Koz did to my sample - note the sample he mastered does not have the hum I am referring to, whatsoever. I did that reading while the neighbors’ air conditioners were off to the give the cleanest sample I could. Primarily I have time to read only throughout the late morning/early afternoon, and the acs are whirring on and off about once or twice an hour at that point.

If you listen to my earlier samples, the ones that definitely have the hum I’m referring to, you’ll know it’s there. The “Tyrion” sample from last night was me at my “best” - no ac humming, as much silence as I could muster. Last night’s sample isn’t problematic, in my view. All the prior ones, on page 1 and such (ac hum 2.wav) feature this humming.

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The “Tyrion” sample from last night was me at my “best” - no ac humming, as much silence as I could muster.

And it sailed straight through mastering. So now you know the goal and know that it is possible using published techniques and tools.

Now you also know what studios do. You walk in and close the door and your ears pop from the silence and you start to hear your own heartbeat. Sit down, announce the work and go home. There are posters who decided to stop hiring the studio and record at home. They’re encountering the same problems you are. The ACX specification for noise is -60dB. In English, the background noise has to be 1000 times quieter than your voice.

That’s not easy.

Home performance artists never pass noise. Even me with my mostly soundproofed third bedroom has to lock the ticking wall clock in the bathroom and wait for traffic to die down. You are warned not to depend on Effect > Noise Reduction unless it’s to clear up some very tiny background hiss. Stiff application of Noise Reduction will damage your voice. ACX hates Noise Reduction and they’re waiting for it.


Yeti Curse is the name I gave to a problem where USB services interfere with each other. The insanely popular Blue Yeti microphone keeps showing up with this error and yes, I know it’s only because there are so many of them in use.

We designed a tool specifically to suppress this whine (Frying Mosquitoes), but you should really change either the microphone or the computer to get rid of it.

Or, to bring this around, stop using the computer.

Koz

46

You’ve got an amazing voice by the way, Koz.

Thanks but it’s mainly a monotone and puts people to sleep. I’m better than warm milk. Really.

zzzzzzzzzzzzzz

Koz

47

I appreciate a soothing, buttery smooth voice. Suppose it doesn’t speak to your overall storytelling prowess, but I could fall asleep to it, happily!

Okay, let’s keep the ball rolling, then - in the event I do need to forego the laptop and mic (setting 3 on the Snowball still works just fine) could you recommend a portable audio recorder like the one you showed me?

And to come full circle, if I’m picking up what you’re putting down, recording during the ac hum is ill-advised, as I’ll have to rely on noise reduction to have a non-terrible product, which ACX could potentially hound me for down the road.

Steve mastered a sample of me speaking, with the hum, in the first few pages. The hum was pretty much gone, though there was a “tinny” quality to my speech. (https://forum.audacityteam.org/download/file.php?id=24393)

I assume ACX would not love this tinny quality.