Through spectral analysis of the commercial mixes I've noticed that almost always there is might low sub-bass here, even in rock mixes. Is it depends on the treatment of the kick drum and bass (usually I cuts sub-bass on bass-guitar) or it is simply the result of adding bass exciter on master bus?
It can be done by a master house. However, mostly this gets done during the mixing. For sure the kick and the bass have to work together as one. You can achieve this with EQ. To begin you can insert a bell EQ somewhere around 50Hz on the kick and give it 4dB gain. Do the opposite on the bass, -4dB at 50Hz. Boost 4dB around 120Hz on the bass and do the opposite on the kick. You can add an extra sub to the kick and the bass by inserting the Maxbass on a parallel FX track. You can also try to copy the bass track and transpose it -12 semitones. Insert a lowpass filter, compress the snitzel out of it and blend that in with the original track.
I forgot one thing to mention about balancing the two. This can be tricky because most project studio's don't have monitors with an extended low end. Insert a VU (Waves needle meter, for example) on the master bus and set the master bus fader at 0dB. After you did all the processing on the kick and the bass, turn these tracks in solo and faders down. Bring in the bass till the needle hits an average of -3dB VU. After that, bring in the kick till the needle hits 0dB VU. This gives you a good starting point, most of the time. Have fun!