I agree with others who have posted the comment that one should not "hear" a subwoofer as a separate entity.  If your ears can localize where in the listening space the sub is placed, then its crossover frequency is set at too high a value, and its overall volume is probably set too loud.  This is a common mistake for new owners of subwoofers:  they want to "hear" their investment in action! This is entirely normal, and may be preferable during the honeymoon period with one's new subwoofer acquisition; after a certain period of time elapses, the user will become annoyed with the new subwoofer's sound in the system, and will probably sound unnatural, and too easy to be located by ear.

Remember, when you set a sub to start rolling off at, say 100Hz, you can still hear it at 200Hz (roughly note Ab below Middle C) and 400Hz (roughly A-flat above Middle C), when the cutoff filter is 6dB per octave.  Restated, a 100Hz low pass frequency allows 100Hz, but is -6dB@200Hz (about A-flat below Middle C) and only -12dB at 400Hz (about the first note A-flat above Middle C).

If you have smallish monitor speakers, it might be fine to feed your monitors the full frequency signal and just let their low frequencies roll off naturally; the sub's frequencies of the piano will be felt where the monitor speakers are simply too small to render much low frequency sound down there.

Personally, I own a pair of B&W Matrix 801 Series speakers and run them full range, and still use a subwoofer to augment their bass, setting the sub's low pass crossover at about 50Hz.  Ironically, I am able to feel the sub's lowest bass without being able to locate its position in my studio, yet the lowest bass "seems" to emanate from the studio monitors.

Remember this:  The lowest Note A on a standard piano has a fundamental frequency of 27.5 Hz; the octaves of note A above the lowest piano note are 55Hz, 110Hz, 220Hz, 440Hz, and so on.

Hope this helps; this is not the definitive reply to all matters pertaining to subwoofers.

Cheers,

Joe

Have you managed (I looked but I dont seem to find ANY AT ALL) to see an example of an arrengement performed for a fellow Pianoteq user where we can REALLY hear the goodness of Pianoteq and could point me to?

I mean, one where the sound is nice enough and also were "resonances, harmonics...." are found?
Is so, I would not mind making several investments in order to reach such level but in all fair, I havent hear yet such an example (from a real person like us) to make me want to spent extra money in extra equipment

And yet one more question, nothing to do with Pianoteq:
Do you guys think that if I use my line outputs in my digital Kawai CA78 to connect them to my existing Sub, would this help in the overall sound of my own sound in my digital?

Thanks

And do you think the resulta in Pianoteq would pay up the investment?

If my speakers handle 50 as you say, what's the lowest a bass piano sound would go?

I'm really nothing technically should you see that any of my questions make no sense whatsoever

All this confuses me so much LOL

If your UR-44 driver recognizes multiple outputs, you can assign specific outputs to each microphone in Pianoteq Standard. Being one of the outputs for a microphone specially positioned for the subwoofer channel.

I am wrong?

My speakers are active so the sub is plugged directly from the audio interface and so are my near field monitors (I still got two extra line out in interface if needed

With this in mind, its 80/100 still the finest cutoff?