How would i make a VU meter or Spectrum Analyzer?

jorge · 29 Feb 2004

There's a lot of things that are already possible with synthmaker but that I havent tried yet. I normally just test the low-level components on their own as small units of testing. When things are a bit more stable I'll start creating high level modules like the ones you suggest.

I need to get back to FFT / Spectrum components to tidy them up. Things I have done before related to it that you might have seen in the example that loads with version 0.8.0b is to show the frequency response of a filter. There is a TestImp component in the Test group of the Green toolbox tab that generates an impulse wave, when you connect it to the filter being tested you get the impulse response in the output. If you do an FFT on the impulse response you get the Frequency response. If you're only worried about the shape of the frequency response you can use the Norm component to normalize it so it fills the whole Graph area.

The problem with version 0.8.0b is that it doesnt have any prepared modules. Before that I used to have two display modules one for displaying the wave and another for displaying the FFT. They're quite quick to create and maybe the best is for me to create them and give them to you or if you prefer I can create a new setup with a couple of modules that you require. Just let me know.

I dont think I'll do much work today ( Sunday ) and I might be out most of the day. From tomorrow morning ( Monday ) I should be online on MSN and in the chatroom, if you get in touch with me I can quickly do a new version with your requested modules and send it to you.

beno · 22 Apr 2005

What ever happened with this?

Anyway, I'm still curious how one would make a simple level meter. I need to use the timer right to take a sample every so often? Or am I way off?

Ben

jorge · 23 Apr 2005

This is still experimental and it will evolve but it should demonstrate the beginning of a spectrum analyzer version 0.9.3d now has MonoToGraph and WTimer beta components that can be used to create a spectrum analyzer: [old link] The WTimer component generates a trigger 30 times per second.

An example schematic can be downloaded from: [old link]

beno · 23 Apr 2005

Thanks jorge, this helps me see how to approach this. This also illustrates a good reason to have a button (or some other ability) to enable/disable playback of the synth maker audio engine. When this example is open, you always hear the arp tones. It would be nice to be able to stop the sound engine to work on things and then be able to restart it to see what the affect is. Thanks again for the new build and the example. Ben

stefan · 23 Apr 2005

beno wrote: Thanks jorge, this helps me see how to approach this. This also illustrates a good reason to have a button (or some other ability) to enable/disable playback of the synth maker audio engine. When this example is open, you always hear the arp tones. It would be nice to be able to stop the sound engine to work on things and then be able to restart it to see what the affect is. Thanks again for the new build and the example. Ben

Just disable the ds/asio out 🙂

beno · 23 Apr 2005

Duh, I'm thick. Thanks stefancrs. Ben