Noise problem

Here are two spectras :

  1. Cubasis
  2. Auria

Both apps were feed by an input signal 100Hz, ( -50db) , and both have a compr/limiter set to amplify
maximum to reach an output signal of 0db.
( both compr./Limiter were set to attack / release time to 100ms )

You see the noise (SNR) and distortion/THD) on both apps.
The Cubasis is unacceptable bad. SNR=37db and THD = 1,8 %

AURIA ( and also I tested DAW-Multitrack) has good noise figures.
SNR=62db and THD = 0,08 %

The THD and noise is the same at 1khz. ( the spectrum is just better to see with 100hz )
Cubase3.jpg
Auria3.jpg