Thimeo Stereo Tool 9.61 / 9.50

Stereo tool is a software-based audio processor which offers outstanding audio quality and comes with many unique features. It is used by over 1500 FM stations ranging from small local stations to 50-100 kW stations and nation-wide networks with dozens of transmitters, thousands of streaming stations and many DAB+, HD, AM and TV stations. It can be used for both live and file based processing.

If you don’t use Stereo Tool for FM processing, Basic suffices.

FM Standard offers “standard” FM processing, stereo and RDS encoding. The processing in this license is comparable to what many high end (00+) hardware boxes offer. In most markets, this license will make you one of the louder stations on the dial.

FM Professional adds our special Composite Clipper to the processing. This is the same clipper that’s in the Omnia.9sg and the Omnia.9 and Omnia.7 are being upgraded to it. The Composite Clipper takes the stereo pilot, stereo encoding and RDS into account when generating the composite MPX signal, which increases the headroom for audio by a lot. You can typically generate a signal that’s 2-3 dB louder without sounding more clipped, which results in a much more dynamic and much higher fidelity signal. Beside that it unlocks our “Asymmetric L-R” mode, which adds another 1 dB or so. Beside these advantages to the audio signal, the clipper can also analyse the RF spectrum after the exciter, and optimize the signal to reduce reception issues in fringe areas and in multipath areas.

If you can use Stereo Tool to generate the composite MPX signal, we highly recommend the FM Professional version, which sounds much better and improves your reception. To be clear, with FM Standard you’re not doing worse than most high end hardware boxes, but FM Professional really takes it to another level – assuming proper hardware you’ll be the loudest and cleanest station on the dial.

Declipper

Due to the so-called loudness war, where everyone wants their track to sound louder than any other track, nearly all music from the last 20 years or so has been clipped during mastering. This causes several issues:

It sounds distorted
It lacks dynamics
Low bitrate codecs are using a lot of their bits to encode the distortion, leading to much more lossy compression (MP3, AAC, …) artifacts.

To make things worse, audio processing tends to boost softer sounds, in this case, the distortion, which worsens these problems. The Declipper repairs the audio before it enters the processor.

Our declipper is also used by police forensics labs. The following video shows what it does to clipped audio:

Delossifier

The Delossifier improves the sound of lossy compressed audio. It’s targeted at repairing low bitrate MP3 and MPEG2 files. Use this if your playlist contains low bitrate tracks. (But please, do everyone a favor and replace them…. With clipped audio that’s usually not possible, but low bitrate is a different story.

Advanced Dynamics

Advanced Dynamics was added in Stereo Tool version 8.50. It consists of 2 parts:

Auto EQ
Dynamic ratios

Auto EQ is the most spectacular part. It adjusts the sound before the AGC without compressing it. This makes it possible to have a much more consistent output without sounding processed. Since it doesn’t compress the audio, it doesn’t add density and doesn’t cause pumping or breating. Auto EQ can achieve the same spectral consistency that multiband compression can, without those side effects. It does not affect audio levels, only the spectrum.

Dynamic Ratios makes it possible to have a different ratio in the compressors depending on how much they are pushing the level down. When it gets deeper, it gets steeper. So a very loud sound will be compressed more.

This video shows the Auto EQ in action:

Changes:

AGC: Added bands 3/4 (part of Advanced Dynamics license).
AGC: Added Sudden Dump Protection, speeds up release when level drops a lot. Increases maximum release speed, stops Release Hold and Windowing.
Analog compressors: Added Progressive Ratio (part of Advanced Dynamics license).
Auto EQ: Added “Go to center” for near-silence per band, avoids excessive boost of near-silent bands.
Multiband Compressor 1: Added “Go to target” when gating, with hold delay. Reduces excessive boost of bass and highs on voices, a.o..
True Bass: Added “Sub Bass Boost” subfilter with sidechain compressor to improve bass level and consistency.
AGC: Added Progressive Ratio (possibly useful for classical music; doesn’t fully work with Sudden Jump Protection).
Multiband compressors: Added option for pre-emphasised compression.
Kantar: Split to a separate plugin DLL for easier validation of new versions.
Advanced Clipper: Added asymptotic mode. Makes step from not clipping to clipping less abrupt, but also causes some extra distortion.
RDS: ASCII remote access: Added DPSTEXT command that sends RT and PS text in one go and uses word wrap for PS.
RDS: ASCII remote access: Hardened to ignore unexpected characters (EOF’s among others) in the data.
Advanced Clipper: Default settings: Changed frequencies for even harmonics from 1000/2000 Hz to 400/800 Hz to avoid issues in older presets.
Linux version: Jack behavior improved, names corrected (FM/normal output), latency reduced.
ARM version: Set a slightly higher minimum latency value.
GUI: Show a popup message if the sound card buffer filling gets too high or too low.
GUI: Streaming .dll’s not found error message improved (clear message instead of a weird hexadecimal code).
GUI: Updated French translation.
Modern web interface: Fixed μ character display in modern webinterface.
XST/SST web interface: Added Quick Adjust settings to main page (which was empty before).
Bug fix: Modern web interface: Fixed horizontal scrolling issue.
Bug fix: RDS: Code was sending euro sign as an E, but the euro sign ASCII code in RDS is actually an à.
Bug fix: MicroMPX: ARM version: Previous (retracted) release (combined with Stereo Tool 9.52) was incompatible with all other versions.
Large code refactoring in I/O code to enable future improvements.
Added and updated presets.
SST/STX: Updated presets.
MicroMPX: GPS support for Single Frequency Networks (SFN’s) now works fully, and on a lot more hardware:
MicroMPX: GPS: Added support for GLONASS, Galileo and Beidou satellites, besides just GPS.
MicroMPX decoder: Added measurement of sound card delay to handle differences on restarts (needed for HifiBerry on Pi, among others).
MicroMPX decoder: Added displays for NMEA timestamps, stream timestamps, 1PPS pulses, audio feedback measurement, current resampling factor, lock.
MicroMPX encoder: Added displays for NMEA timestamps, samples between NMEA timestamps, clock speed adjustment, lock.
MicroMPX decoder: Reduce maximum resampling value from 0.1% to 0.05% to fix potential RDS reception issue. Large clock speed offsets will now cause dropouts.
MicroMPX encoder: Restart GPS sync on sound card restart, also for plugin version in Stereo Tool.
MicroMPX decoder: Reduced CPU load by about 2%.
MicroMPX libraries: Add thread affinity settings.
PhoneBooster initial version released!