MADRIX Forum

Dear all,

I am working on some sound detection with MAS script using the Frequency Bands provided by Madrix. Unfortunately I am not much of a sound guy but simply a computer scientist, so I don't really know the subtleties of sound.

I have bought a microphone https://www.google.com/search?q=AT2020U ... refox-b-ab that records the sound. When playing a sine tone at different HZ (with my phone) the equalizer effect always shows some noise, mostly at the low frequency bands (but sometimes also over the complete band) which is around half the amplitude of sine tone amplitude.



Where does this noise come from? I didn't expected a clear signal but this low frequency band noise seams a little strange. It also comes with other sounds like cheering with glasses....

Maybe someone can give me a hint to why?

thx

Richard

Are you able to do a second test with another microphone, let's say from your laptop/notebook computer?
As a first thought, it wouldn't surprise me if this is caused by the microphone itself, since you seem to be getting it on every sound input.

Seams to be the case, if I use the laptop microphone it gives me different noise.

Another question: Why are the frequency bands avalible in MADRIX from 5 HZ - about 12000HZ? and not form 20 -20000HZ?

Hello schaf82,

In our oppinion the visualisation of the analized frequencies up to approximately 11.5kHz are sufficent to get a good result. The higher frequencies mostly don't have engough energy to get a good result. If we visualize also this frequencies in for instance single bars of the "S2L EQ/Spectrum", you will see a very, very low high (nearly 0) of the bars which are respondsible for the high frequencies.