We have identified a bug in the range of the contrabass (double bass, string bass) within the Sight-Reading Builder (SRB) of SmartMusic. While our developers work to correct this problem, we have created a workaround that will use the proper range for the contrabass.
When creating an example in the SRB and choosing instrumentation either from Solo Instruments or Ensembles, the contrabass will use the Cello range by mistake. In some cases, this will not be a problem, but starting with Level 4 difficulty, the written cello range dips below of the written range of a four-string bass in standard orchestral tuning.
A temporary solution here is to choose Custom ensemble > Build from scratch.
Then you can select the Instrument Family > Instrument, and set the Full Staff and Abbreviated Staff names. You can add additional staves under the See More dropdown. Once finished, select Save ensemble setup and continue with the SRB settings. This will allow the proper contrabass range for these examples.