Re: Audio Spectrum analyzer help

Hello Mike,

I want to build a cheap audo spectrum analyzer, but im not actually going to
be doing true analysis with it or anything like that.


> ...

I was thinking about using a 4017 to scan the display, wiht a shitload of
active bandpass filters and 4016 ICs to select each bandpass filter in sync
with the scan.

This would take alot of parts, but if there is a simpler way to do this, let
me know.


A simpler way these days would be a DSP or a powerful micro controller. If going the uC route you'd need one with a hardware multiplier to make it anything close to real-time. And a good ADC.

If you aren't inclined to jump into weeks of programming Tim's suggestion with switched capacitor filters is worth checking out. Look at the National Semiconductor LMF100, but it'll cost a few Dollars. Their MF10 is cheaper though I am not sure about availability.

There has got to be some chip that does this. We used to have a stereo that had such a 'frequency bin display' and it wasn't too high end. Not 12 bars but maybe eight or so. Unfortunately it ain't here anymore so I can't open it up and look. IIRC it was from Kenwood and there wasn't anything really massive in parts where the cable of that display went.

Regards, Joerg

http://www.analogconsultants.com
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