Tone Control

Modern loudspeakers, such as ESU sugar cubes or even with passive radiator technology, in conjunction with the HiFi technology of LokSound 5 decoders, enable a sound quality that has never been achieved before. However, the new loudspeaker technology unfortunately requires a different interpretation of the “mastering” of project files. It became increasingly difficult for our sound engineers to find a compromise that would enable a good sound reproduction with all available speakers. It was necessary to adapt the sound to match the speaker, which the user could also do after installing the decoder.

LokSound 5 decoders from firmware 5.9.159 now include a unique Tone Control feature in the form of a Bass and a Treble control. The Tone Control is implemented in the decoder's firmware. The sound files do not necessarily have to be rewritten. This is important if the source file is not available.


As known from stereo systems, a bass control allows you to raise or lower the low frequencies to adapt the "bass" reproduction to the speaker. The treble control, in turn, optimally adapts the higher pitches to the model and speaker. The frequency ranges can be reduced or increased by up to 10 dB. This only requires two CVs, which are located in the “Sound Settings” menu.

The bass reproduction is controlled with CV 196. The average value of 16 leaves the reproduction unchanged, smaller values weaken the bass reproduction, larger values increase it.

The treble is influenced in the same way using the CV 197.

In order for the Tone Control to work, the decoder firmware must be updated to version 5.9.159 (or higher). This is done using the LokProgrammer software 5.2.5 (or newer).
After updating to the latest LokProgrammer software version, first Read In the decoder.

The LokProgrammer will show you the firmware currently on the decoder at the bottom left, which now needs to be upgraded to 5.9.159 (or higher). To do this, press the “Write decoder data” button.

After clicking "Next", the LokProgrammer will automatically update the firmware. The two new CVs 196 and 197 will also be available afterwards.

You can then test and adjust the sound directly in the Virtual Driver's cab. For this purpose, three controls have been added on the right, which write both the overall volume and the desired bass and treble settings directly to the decoder via POM as soon as you change the sliders. This means you can test the result directly in real time and adapt it to your speakers and personal taste.


Increasing the frequencies may make it necessary to reduce the overall volume: In particular, the ESU loudspeakers with passive radiator technology (50344, 50345) may otherwise make "cracking noises" due to overload.
The sound control automatically removes very low frequencies that the speakers typically used in the model railway sector cannot reproduce anyway, but which lead to unnecessary strain on the speakers and audio amplifier. The ESU tone control works automatically and nothing else needs to be set. This means you can adjust the sound in just a few minutes.
If the project file is available, the volume of individual sound slots can also be adjusted individually.