Nigel Goodwin said:
xmat said:
Imagine you have a function generator in your lab and feeding the circuit with a sine wave of 100 hz, in a volume level of 50db, let's say.
Since the variation of the signal is slow and steady (no transients), the circuit does not understand that a signal is fed into it.
Then, if I feed a signal with transients (i.e something that has a rapid evolvement--like a clap) in a volume level of 10db, the circuit will be able to tell when that a sound (beat) is fed into the circuit...NOW?
You appear to be missing my point :lol:
You've just described an experiment, I don't believe that's what your project is about?. That particular example doesn't help much either because it uses db's, without giving any reference (a db is a ratio, NOT an absolute value). But am I to understand you're wanting to detect an audio event 40db LOWER than the background noise?.
Which is why I would like to know what it is?, or some reason why we can't be told? - perhaps we could then offer informed sugestions instead of stabbing in the dark.
BTW, in the example above, how about a 100Hz notch filter to kill the 100Hz? - although if 40db higher was what you meant, it's a LOT stronger than the signal you want.
That experiment is indicative of what I am trying to do.
There are many applications that this circuit could be used, from beat detection to midi-scoring of musical context...All pretty much related to interpretation of music (music genre) and linkage to video media etc etc..Numerous applications which I think that by mentioning them there is really not much of a difference....since...
....I have this signal processing problem, I told you what the problem is, how I think it can be solved and all I hope for is
a schematic suggesting a solution.
Db is indeed a ratio, that is why I used it, cause i thought it resembles fluctuations and is a relative and not an absolute value.
Well, maybe it wasn't the best way to say that background sounds are louder than the sound it has to be filtered for beat detection of a musical-content sound.40 db was "a matter of speech".
Noise refers to music, not really noise (guitars, vocals etc etc).Within a song these elements dominate over rythm instruments, in the sense that they appear louder and more "in-your face".
However, they appear to have some form of rythmical content, which is both good or bad;
good when they follow they main rythm and bad when they are not.
The latter case I am to examine.
I can't kill 100hz cause its part of the fundamental frequencies existing in the sound I am trying to extract rythm from.
So, how about a suggestion?I am pretty sure you all find the issue intriguing in technical terms;
is there someone able to suggest a solution?
xmat.