Faber Acoustical Forum

Faber Acoustical iOS Apps => SignalScope => Topic started by: Frequency And Sulphur on July 13, 2008, 10:46:57 AM

Title: Spectrograms (as opposed to a real-time spectral slice)?
Post by: Frequency And Sulphur on July 13, 2008, 10:46:57 AM
Any chance that SignalScope for the iPhone will be getting a spectrogram display in addition to the FFT analyzer that seems to be on there?  Real-time would be nice, but more useful (to me) would be the ability to record a short segment and then draw a zoomable spectrogram?

This would be very useful for me, as it provides a somewhat more conventional way of looking at speech acoustics.
Title: Re: Spectrograms (as opposed to a real-time spectral slice)?
Post by: FaberAST on July 14, 2008, 08:22:20 AM
Yes.  A real-time spectrogram is in the works.

Ben
Title: Re: Spectrograms (as opposed to a real-time spectral slice)?
Post by: overtones on July 15, 2008, 07:02:09 PM
Hi there, I also had the familiar problems downloading this app, but it updated itself onto my iPhone this evening, and it looks fantastic. A really great program!

My background is in music, so although I know a lot about frequencies and stuff I'm certainly not an expert on this type of program. Perhaps a lot of iPhone users will be like me. I'm not sure exactly what a spectogram is, but I suspect that is something I am looking for too. Just so you know what I would be trying to use your program for:

1. Illustrating vowel shapes to singers (shape of strength of overtones)

2. A visual way to encourage singers and instrumentalists to produce a stronger 'tone', by which we usually talk about producing stronger overtones (upper harmonics).

I've fiddled about with the settings, I wonder could you recommend any particular settings for the uses I mention there. For instance I think linear works better than log for the frequency side of things.

And once again thanks for a brilliant app!
Title: Re: Spectrograms (as opposed to a real-time spectral slice)?
Post by: FaberAST on July 15, 2008, 09:10:51 PM
overtones,

It sounds like a spectrogram would be very valuable to you. You can take a look at our Mac software for sample spectrogram displays (http://www.faberacoustical.com/products/signalscope_pro/spectrogram/).

For now, with SignalScope on iPhone, your best bet may be to work with a linear frequency scale and a dB magnitude scale. Increasing the number of spectral lines will improve the frequency resolution, but it will slow down the responsiveness of the spectrum display. A little trial and error can help you find a setting that you like best.

The harmonic cursors may also be helpful.

Enjoy!

Ben
Title: Re: Spectrograms (as opposed to a real-time spectral slice)?
Post by: Frequency And Sulphur on August 23, 2008, 06:40:31 PM
Any updates on this?  I'm very eagerly anticipating a spectrogram option, even more if I could set the window length on the spectrogram (to reveal formants in speech, for instance).
Title: Re: Spectrograms (as opposed to a real-time spectral slice)?
Post by: FaberAST on August 25, 2008, 09:24:46 AM
There's nothing to announce yet.

What range of window lengths would you be looking for?
Title: Re: Spectrograms (as opposed to a real-time spectral slice)?
Post by: Frequency And Sulphur on August 26, 2008, 12:15:05 PM
I'd like to be able to switch to a window length around 0.005 seconds to get a good broadband spectrogram :)