Questions tagged [measurements]

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1answer
46 views

Why not pointing the loudspeaker toward the sky during open-field frequency response measurement?

I'm skimming over documentation relative to loudspeaker frequency response measurement. Regarding open-field/far-field measurements, most authors mention issues with the ground reflection. For ...
1
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1answer
56 views

How to interpret the analog output of an SPL meter?

I tried to connect the analog output of a Sound Pressure Level Meter to a digital oscilloscope to determine the RT60 of a room. I thought I will somehow have an analog reading proportional to the SPL....
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3answers
96 views

How do you convert sound decibel (dB) measurements to a common loudness scale?

I'm using Android IP Webcam as a sound sensor to monitor environmental noise levels in an interior room. It is outputting values in the 135-230 dB range where ~135 dB is dead-of-night, everything off,...
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0answers
22 views

Windows tool to extract the tonal centre of an audio track

Essentially I want to accurately measure the key that a piece of a cappella music is performed in, to analyze the portions of the piece that are responsible for the tonal centre dropping. The ideal ...
1
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1answer
49 views

Adobe Audition / Audacity: If I sum all the bins of a FFT (rectangular window), do I always get RMS Amplitude?

First I use Audacity to perform an FFT of an audio clip with a rectangular window. Then I sum all the FFT bin values. Since the FFT bins are expressed in dB, I perform the "decibel sum" like this: ...
2
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1answer
54 views

How can I measure the sound intensity outside my house?

If I wanted to measure the noise outside of my house, in decibels, let's say I want to take a reading every second for one month and record these measurements in a file: a CSV file or something of the ...
1
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0answers
34 views

Directivity index measurement - steps to follow

I am interested in measuring the directivity index of a loudspeaker. I have been looking on the Internet information about the setup, but unfortunately the information I have found so far has to do ...
2
votes
1answer
478 views

Unrealistically low round-trip latency measured

I am trying to determine the roundtrip latency of a dusty old Toneport UX8 audio interface I have laying around, and I am getting some unexpected results. I am testing using CEntrance ASIO Latency ...
3
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1answer
136 views

cheap hand held sound meter vs smartphone app

For learning purposes i want to play around with a sound meter. Are the smartphone sound meter apps (have a droid 2) that accurate? Is a $30 hand held sound meter usually going to be more accurate?
11
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3answers
3k views

DIY Portable Anechoic Chamber

I would like to perform some measurements of the microphones (i.e. frequency response, SNR, etc.). First and best option would be to use the Anechoic Chamber- obviously this is not an option because ...
3
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1answer
1k views

Decibel levels of animals

Im looking for some kind of list with DBSPL Levels of different animals. How high they shout, scream or sings. I've got a feeling there's something like that out there somewhere but google isn't my ...
4
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1answer
1k views

What is the difference between dBFS and dBu?

What is the difference between dBFS and dBu for leveling when it comes to final mix and standards for cinematic release? I know that each country is different. In South Africa, the spec for ...
11
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2answers
3k views

What do sensitivity measurements of microphones really mean?

Microphone sensitivity is usually measured in mV/Pa. If one mic is say 25 mV/Pa and another is 13 mV/Pa how much more sensitive is it in application? How can I figure out how much more gain the mic ...