This program started as a simple FFT program running under DOS a long time ago, but it is now a specialized audio analyzer, filter, frequency converter, hum filter, data logger etc .

Main features:

- Input can be taken from the soundcard, but the "audio utility" interface makes it possible to create an interface to any A/D converter you like (for example a PIC with serial interface). A plugin for Winamp allows to analyse audio streams from the internet (see download section).
Besides the soundcard and the interfaces supported by the "audio utilities", SpecLab directly supports SDR-IQ and SDR-14 (by RFSpace, Inc), and PERSEUS (by Microtelecom s.r.l.).
- Demodulated output is usually sent to the soundcard, but can be sent anywhere else (including an MP3- or OggVorbis encoded stream using Winamp/Oddcast and a special Audio-I/O DLL, which acts as an input plugin for Winamp).
- Selectable and adjustable waterfall color palette allows you to change the contrast of the waterfall display during and after receiving spectrum lines ("contrast" & "brightness" - sliders)
- Frequency range can be adjusted while running, the old part of the waterfall display will automatically be re-drawn without stopping the audio processing.
- Special waterfall mode for "Radio Direction Finder" with colour-coded azimuth display, based on DF6NM's Wideband Direction Finder with Colour Encoded Spectrogram Display. Now with up to three "notches" (adjustable nulls in the synthesized antenna pattern) to suppress noise from certain directions.
- Special "multi-strip" waterfall mode for long term observation of relatively narrow bands
- Reassigned spectrogram for higher time- and frequency resolution, if certain conditions are fulfilled (since 2009-06)
- Support for image-cancelling direct conversion receivers ( quadrature input via stereo soundcard )