Audacity Forum

kozikowski wrote:Third time.

Do you have the microphone sitting on the table?

Koz

Oh, I answered that earlier. Yes, it is on the table on my desk that is padded with a blanket.

I answered that earlier.

Missed it. Sorry.

I don't have any better ideas, so let's go with the bath towel solution.

Fold up a bath towel and put a book on top of it. Park the microphone on top of the book.



That should eliminate any vibration from the desk or floor. Note it's sitting on the table moving quilt.

The sound test is muffled, like it's having a hard time getting into your cave. But not hard enough time.

I think the worst problem you have right now is not knowing when the motor comes on. Can you feel the heat or air conditioning come on? Do you have that kind of HVAC system? My old house Heater/AC had provision to just shut it down. OFF.

Koz

Ok I will definitely test that out.

Well, I am in an apartment complex and I think it might be the buildings water heater upon further inspection
We control our own heater and I never have it on when recording.

Pack it up and try your equipment somewhere else far away. If the clicking goes away, you'll know it's something in your building. If not, it's something to do with your equipment. If it turns out to be interference from your building, you're in trouble. You may never find the source, and even if you do you may not be able to do anything about it. Your only option may be to change your equipment to something less vulnerable to interference.

As for the noise floor, try to find something like a studio to see if recording there will affect the noise floor. Try a closet full of fur coats or just draping a huge quilt over your head and shoulders. If the noise floor drops, you'll know that the solution is to build a real booth in your apartment (not difficult, I did it for under $100). I'd also try recording to another computer just to see if that changes anything.

If the clicking goes away, you'll know it's something in your building.

It's not clicking. It's almost classic electric motor noises. Listen to the sample. And it's complicated by not being there all the time. So even if you do move out temporarily, it's rough to know if it worked or not.

There was a recent poster who had 'sometimes noises' which turned out to be their external hard drive spinning up. They had their laptop, drives and microphone close to each other on a table, so it was rough to hear what was going on in real life. But it was close enough for the microphone to pick it up.

a real booth in your apartment (not difficult, I did it for under $100)

How?

Koz

a real booth in your apartment (not difficult, I did it for under $100)

How?

Well I guess that depends on your definition of "real". This is definitely an amateur job, but it works nicely for my purpose, which is not being able to hear screaming kids. I chose the quietest spot in my house, the attic, and built a closet out of 2 by 3s and noise insulation bats you get at the hardware store, and lined it inside and out with one inch sound absorbing board. This includes the door, which is more like a wall on hinges. For air, I fed a 3" duct from a hole in the ceiling to the input (the WRONG end) of a $12 bathroom fan. I added a fan "dimmer" and put it on lowest setting, which gives a low hum outside of the booth where the fan is, but is barely audible within the booth, and creates enough negative pressure to let air seep in through the cracks and keep me from suffocating. Because the booth is so small, the price of materials was low. I actually regret not having made it bigger, as it would be a nice study or rest area if it were more roomy.

This is definitely an amateur job,

Unless you're going to give tours, it doesn't have to be elegant. One poster did it with plumbing supplies. It's pushed together. No glue.




I did it with furniture moving pads. Mine had to knock down for transport.

For air, I fed a 3" duct from a hole in the ceiling

That kills a lot of people putting studios in their coat closets. Ian in Hollywood has to some out periodically and gasp for air.

Did you have a chance to listen to that clip?

Koz

Notch filters in Audacity's Nyquist prompt can reduce the "cement mixer" ...
The "cement mixer" sounds more like a mains-hum to me, rather than acoustic like a motor,
as the loudest component is exactly 120Hz , (2nd harmonic of 60Hz mains)

kozikowski wrote:Did you have a chance to listen to that clip?

I can hear a nasty hum that sounds like a machine, but that doesn't mean it's a machine at all. It doesn't sound like mains hum to me ( except possibly the harmonics explanation, I wouldn't know). Since it's intermittent, then it's not mains itself, but maybe some other source bleeding over into mains. If it's a laptop computer, one could try unplugging it and running on battery. Power supplies can have intermittent problems. I would increase the gain and try moving around the apartment while listening, to see if the noise varies. That could either help pinpoint the source, or if there is no variation at all, it can indicate that the problem is with the recording equipment.

kozikowski wrote:

This is definitely an amateur job,

Unless you're going to give tours, it doesn't have to be elegant. One poster did it with plumbing supplies. It's pushed together. No glue.

There are of course limits to what makeshift booths can do. I recorded this just now. The fiddle rang in at -48, still enough to totally wreck a recording.