I am having good results blending modded versions of Pianoteq's NY Steinway Jazz Recording preset and the Studio Grand patch in a Roland RD-700NX.
Like you, I found Pianoteq to be wonderfully responsive but lacking in timbral richness and naturalness/realism. My goal was to have the Roland provide the primary timbre and augment it with the 'livelier' harmonics and sympathetic resonance of Pianoteq.
To this end, I made a number of changes to the NY Steinway preset and set up the layering as follows, hosting the VSTis in Cakewalk by Bandlab (CbB);
- Disabled the Reverb, Delay and Limiter in Pianoteq (it's always best to work with dry sounds when layering).
- Armed the audio tracks in CbB so I would be metering the instrument output levels.
- Lowered the fundamental in Pianoteq by 4-5 dB to mitigate phasing issues and let the Roland dominate.
- Lowered the hammer hardness across the board because the Roland is already plenty bright, and Pianoteq can sound 'synthetic' with hard hammers.
- Lowered the Roland's output volume using MIDI CC7 to equal Pianoteq when playing a big chord at Vel=127 with track gain at unity.
- Raised the dynamic range and tweaked the velocity curve in Pianoteq to match the Roland's loudness response across the velocity spectrum.
- Raised the Damping Duration to match the Roland's longer decay on key-up (hadn't realized how abrupt Pianoteq was until I compared them).
- Increased the Wear and Unison settings slightly to add some 'character' to the tone.
- Mixed the two tracks such that Pianoteq is approx. 5dB below the Roland and the combined outputs don't clip when playing big chords at max velocity.
- Compensated for the latency differences between the two signal paths with a sample delay plugin.
- Applied some secret sauce and reverb using FX in CbB.
I haven't gotten around to recording anything with this setup yet but will try to share something soon.
If you have questions about why or how I did any of this, let me know. But i don't speak Cubase at all so you're on your own there. Matching the loudness across the velocity range to have a constant ratio of the two sounds is probably the most important and time-consuming part of the process, and you want to have most of your tonal adjustments done before that. Initially, you just need to try a bunch of different combinations to find two sounds that work fairly well together without modifications as a starting point.
Others may disagree, but I think this is probably the best approach to blending Pianoteq with another instrument, especially with a sampled piano that has limited tonal adjustability. You need to like the tone of the sampled instrument by itself and use it as the primary element because Pianoteq has all the adjustability.
