AC Noise is just ridiculous ..

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johidi
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AC Noise is just ridiculous ..

Post by johidi »

Can someone please recommend good settings on recorders? I have a Zoom h1n and recently got a sony pcm-d100. I am still new to this, so trying to figure out the best method. I don't usually roam the hallways, and like to just place the recorder in a good location and let it run all night. I am seeing with both of these, there is a lot of ambient/heavy bass noise in all my recordings. While I am at location, it doesn't sound like this, but when I listen back on my computer, it's usually more AC/Ambient sounds then anything and it muddles the audio.

I have tested with 10 setting on the mic level (the circle knob thingy), and this produces the most ambient noise. If I go low to 6 level, the noise is still there but now my overall volume is low with doors closing/opening being even louder, so normalizing becomes an issues.

What am I doing wrong? What do you guys recommend? It's getting really frustrating to come back home and only hear noise.
tweaktweak
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Re: AC Noise is just ridiculous ..

Post by tweaktweak »

It's a bit hard to say. Remember that the ear/brain doesn't hear like a microphone. We can automatically filter out stuff in out brain and ignore sounds we're not interested in. The mic hears everything equally (ok not really of course but that's a whole other discussion).

Looking at the PCM-d100 manual here's some things that might help.

Try Setting the LCF(Low Cut) filter (p35/72 of manual) "When the low cut filter is activated, audio under the following frequencies is filtered and attenuated. This function reduces noise caused by the flow of an air-conditioner, outdoor air, etc.OFF*:The LCF(Low Cut) function is disabled.75 Hz:Audio under the 75 Hz frequency is attenuated.150 Hz:Audio under the 150 Hz frequency is attenuated"

Also, placement can be an issue. Try placing it on something soft, like foam or placing it somewhere to 'de-couple' it from the rest of the structure to help prevent sounds traveling through the floor/wall and into the recorder.

While you don't want the recording too quiet you can always make it louder before it clips/distorts. Cranking the mic volume might be necessary sometime but then keep in mind you might be increasing some of the internal noise of the mic's preamps and internal amplification. Though that's a bit extreme. The built in limiter may help but I'm usually not a fan in these situations. Occasional loud noises like a door slam can be attenuated and brought down before normalizing.

Low frequency noises like rumble and hum can be dealt with effectively after the fact. Noise like AC is more broad band and covers up much more frequency wise. I'm not a fan of 'denoise'ing a recording but sometimes that's the trade-off. And sometimes there's just nothing you can do. If you can practice at home with the radio or tv on playing some talking (or porn or whatever that's in human speaking range). Set it to be relatively quiet or at a natural level and go into another room and see hat you get. Then turn on a fan or the AC or a vaccuum or whatever and see what happens.

I just woke up. I hope that helps in some way.
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