spectrum analyzer that shows 'live' input from the microphone
Solution 1:
sndpeek
No idea if this is any use for you - it's Open Source:
http://soundlab.cs.princeton.edu/software/sndpeek/
sndpeek is just what it sounds (and looks) like:
real-time 3D animated display/playback
can use mic-input or wav/aiff/snd/raw/mat file (with playback)
time-domain waveform
FFT magnitude spectrum
3D waterfall plot
lissajous! (interchannel correlation)
rotatable and scalable display
freeze frame! (for didactic purposes)
real-time spectral feature extraction (centroid, rms, flux, rolloff)
available on MacOS X, Linux, and Windows under GPL
part of the sndtools distribution.
SFS/RTSPECT
Just found this too:
http://www.phon.ucl.ac.uk/resource/sfs/rtspect/
Windows Tool for Real-time Waveforms & Spectra
RTSPECT is a free program for displaying a real time waveform and spectrum display of an audio signal. With RTSPECT you can monitor the waveform and spectral shape of sounds being played into the computer's microphone or line input ports. RTSPECT can display one or two-channel audio signals.
Solution 2:
Just found this one:
http://friture.org/
Testing it now.
Solution 3:
Audacity does allow you to monitor the input from the mic without recording. Don't know if this would reduce/eliminate the delay you experienced, though:
"either select "Monitor Input" from the input meter's pop-up menu, or else just click on the input meter." http://audacity.sourceforge.net/onlinehelp-1.2/toolbar_meter.htm
Solution 4:
Here's another free one. Shows a good spectrum with unnoticeable latency. Also has peak level indicators.
http://www.techmind.org/audio/specanaly.html
Solution 5:
A few other options from this question, particularly useful if you need something with few dependencies and easy to modify:
- A Spectrum Analyzer in one Python script using PyAudio, Chaco, scipy
- A Spectrum Analyzer using Python and PyQt
- A Spectrum Analyzer demo using Qt