Recent content by whariwharangi

Here is data for recording made with 150 seconds. fft size 131072 and 4194304. I also put in 1khz for the 131072 fft size to show the harmonics. Nothing significant shows above 1 kHz. https://drive.google.com/open?id=0B0yOczVuy47tQWpoM3pLSENHNU0 It doesn't look like length of time of recording...

I make a statement at the start of the recording. It helps keep track of where the recording was taken, orientation of microphones etc. Thats probably the 'pollution' you are observing. There isn't usually much above 200 Hz. If I use the lower fft settings the harmonics show up but even that...

The manual for the recorder makes no statement about the frequency range for which it will record, only that it is designed to record music and in particular bass and drums. There is a high pass filter with three settings ... which would block the noise I am trying to record. But there is no...

I gather from this that the 262144 fft size is more appropriate than the 4194304 fft size. Yikes. Yes there is low pass filter included in the software. I don't have an analog filter that would be placed between microphone and recorder. I have been using the software band pass filter to...

The sampling frequency of the recorder is 44.1k, format wav 16 bit. Apparently I can increase the sample rate to 96k. The sample rate on the Spectrum Analyser/Oscilloscope is determined by wav file parameters; no matter what settings I make, it goes to the wav file numbers when I open the...

Yes 60 Hz is supply voltage frequency. I get 120 Hz if I record noise from transformers. The recording data shown here was taken out of doors about 30 meters from any building on a school field using a battery powered recorder. Most of the audible sound from the building is drowned out by a 1/5...

Here are same 3 fft sizes using 5 x Y scale and showing spectrum analyser full screen. https://drive.google.com/folderview?id=0B0yOczVuy47tMXhfN0Z2aWdGVTA&usp=sharing

Slides are here: https://drive.google.com/folderview?id=0B0yOczVuy47tcTRRTHBUT0daUzA&usp=sharing https://lh4.googleusercontent.com/oawQXOZ0YyeDr0qGQLGB8IT5uOX_Ho_maNowqmxlFjEUJQhgZKNI79zf9c94_0VtwrVAxzhJyx5oa24=w1549-h991-rw...

https://drive.google.com/drive/my-drive

I am not hearing the noise; I feel it as if there is vibration. If I do hear anything ... rumbling in the walls ... I go outside and its silence (unless I use earphones with the recording equipment) I actually did identify part of the problem was from a blower on a furnace. Basically it turned...

I am using a Tascam recorder to record an environmental nuisance noise that is occurring in my home. I then use Virtins Multi Instrument Software, which includes an oscilloscope, band pass filter, and a spectrum analyser. Noise source is probably machinery at a legal marijuana grow op. That...