MPXTOOL is a tool to play, record, analyze, compare, encode and decode FM Stereo Composite (MPX) waveforms.

MpxTool is a modulation monitoring suite entirely in software. It contains a reference quality Stereo Encoder and
Decoder, and allows realtime playback and recording of signals.It's an invaluable tool for anyone interested in
the technical side of FM broadcasting, whether regarding Audio Processing or Air-chain Calibration, work or passion.
MpxTool makes it easy to compare audio processors, calibrate your airchain, and monitor other stations off air.

Features:
» Phase linear reference quality stereo encoder automatically encodes incoming L/R baseband to MPX, for analysis.
» Phase linear reference quality stereo decoder with sharp phase linear (FFT-based) filters, for accurate listening
and analysis.
» Built in Signal Generator with loop-back support.
- For calibration of sound card i/o, exciters, tuners, STLs etc.
» Available signals:
- 400hz and 1000hz sine (for level calibration and THD measurements)
- 60hz square (for tilt calibration)
- Quick Sweep 1000-60000hz (for high frequency equalization)
- 31187.6hz, 13586.7hz and 8667.4hz sine (bessel null)
» FM Exciter with RF spectrum analysis - with selectable ITU-R SM.1268-1 "stokkemasker" and ETSI EN 302 018-2 masks. BETA
» The internal FM exciter runs at 1.536 MHz sampling rate and generates a 384 KHz FM carrier, +/-75 KHz deviation
at 100% modulation. For analysis purposes only - no output.
» 5-band Phase Linear Parametric EQ (5 for input, 5 for output).
- Center Frequency 20 to 96000hz.
- Width 0.05 to 10 octaves.
- Gain Range -18 to +18 dB in 0.01dB steps.
» Playback A/B switching for direct on-the-fly comparison of recorded files, with Bookmark feature.
» Advanced calibration/compensation features make it possible to use off-the-shelf inexpensive sound cards for
accurate MPX capture:
- Tilt correction to compensate for non-flat subsonic response.
- Keeps squarewaves from tilting inwards.
- Arc correction - Keeps squarewaves from arcing outwards.
- Peak-sensing DC Servo for the input - calculates a subsonic signal to add to the captured signal, to cancel out
sound card or tuner induced overshoot by re-centering the signal.
- 5-band Phase Linear Parametric EQ
» DPO Oscilloscope (4x oversampled to 768 KHz) with boundary-lines and optional peak-hold for monitoring purposes,
and excellent trig/synchronization for a clear, flicker free display which is unachievable on a standard
oscilloscope. Switchable Composite/De-mod/De-emph.
» FCC-accurate Modulation Monitor, 4x oversampled to 768 KHz for absolute accuracy, with adjustable response time
and peak flasher.
» Spectrum Analyzer with peak-hold for monitoring purposes.
- Sources selectable: Composite, RF, Input (L/R), De-modulated (L/R), De-emphasized (L/R). Filtering available, to
optionally remove pilot, RDS/RBDS, subcarriers etc.
» RF Noise Simulation for accurate simulation of real-world receiver conditions
» Mpx Filtering (for oscilloscope, spectrum analyzer and modulation monitor).
- Allows you to see the signal of interest by filtering out others.
- Remove Pilot - if your airchain does not use composite clipping, removing the pilot makes it much easier to see
the actual audio, and how close to "the edge" it is. It also lets you verify the accuracy of your audio processor.
- Remove Pilot and RDS+SCA. Filtering out RDS/RBDS is essential if you want to use the oscilloscope while adjusting
the audio processor.
» WAV and FLAC file support
» Pilot Indicator with accurate percentage-bargraph
» VU-meters for de-modulated audio. Can be used to indicate the presence of a composite clipper. De-modulated audio
going above 0dB is a sure indication of a composite clipper in the path.
» VU-meters for de-emphasized audio
» Pitch control (+/- 15%) implemented as a reference quality polyphase resampler, to aid in auditioning the high-fre
quency contents of an audio signal, for ears that have trouble hearing the highest frequencies unassisted.
» Selectable 50/75us De-emphasis accurate to within 0.1dB.
» Accurate numerical display of various MPX measurements, including MPX modulation level, Left/Right decoded audio,
Pilot level, pilot modulation and RDS injection level.

Available for users only