Topic: Step-by-step: Modifying a Preset to match a piano - Steinway B to F
This afternoon, as a learning exercise, I spent several hours modifying the Model B "Player" preset so that it would sound as close as I could get it to my Model F upright piano. I learned several things about creating presence, airiness, out-of-tune-ness, and more.
Here is the location where I posted the preset:
http://www.forum-pianoteq.com/file/4qd0a9ku
Here is a short video of my playing both the real piano and the preset back and forth using my CME X-key 37, recorded via my Samsung Note 5:
https://goo.gl/photos/DGyEcmoo34Buvv8T9
… And here is my story:
I bought a CME X-key 37 as a practice keyboard to take with me on trips. It is an excellent gadget, as it has real-width keys that have full MIDI 128 sensitivity to them. It's a bit clacky, as you'll hear in the video, but it sounds much worse in the video than it does in real life. Their software allows you to set up velocity curves for their keyboard, and the touch that you get out of it is nothing short of incredible for having a bunch of chiclet-style keys. They have buttons on the keyboard to move the octaves up and down so you can simulate the full treble and the full bass, as well as a key for the sustain pedal. The curious thing is that since my piano's keyboard (using the QRS piano scan underneath it to generate a MIDI output) is fairly soft, I had to not only create a matching velocity curve in Pianoteq, but I had to employee a curve to first make the CME X-key soft to match the actual piano, so I could build a Pianoteq preset that would be appropriate to use on both the acoustic piano and CME X-key (I guess this is something like the expression "two wrongs don't make a right but three rights make a left").
I've previously posted here about speaker position and orientation. That has not changed, with two monitor speakers at either side of my keyboard/piano facing upwards and two small ones just behind them facing me to augment my treble. I am very happy with that set-up – for reasons I do not understand, the vertically-pointing speakers provide better stereo imaging of the real piano then do the ones facing me (as I have tried just having the bigger speakers facing me, and I did not like it). One of the interesting things was that just having the microphones as set in the Model B preset essentially over the keyboard gave "too accurate" soundfield for the keyboard in front of me. This also was not as I expected, and I ended up defeating it and broadening the sound in several ways, while I reduced the stereo width because the speakers I have on either side of the keyboard make the piano sound too wide if I use the standard 1.0 width.
Here are the changes that I made to get the keys to match (in other words, when I play the high treble or the low bass on the synthetic piano, it sounds as it sounds are coming from the same location as on a real piano):
0) I moved the microphones backwards just a wee bit so that the tips of the microphones touch the front edge of the keyboard – this made a very slight change to the character of the sound, as well as the location of the sound, and made it more realistic. This may vary a bit depending upon where your speakers are placed as to what you hear from the speakers and how your brain interprets it.
1) I reduced the stereo width to 0.40 – This gave an accurate interpretation of playing keys on a real piano and having them sound the same on the synthetic piano.
2) Curiously, and perhaps because I have an upright piano with a solid wood panel in front of me and I left the cover closed, the sound from the real piano is a bit more nebulous than the sound out of the Pianoteq preset. Therefore, I turned on microphones number four and number five in the microphone set that came with the Model B Player preset. I ended up modifying it slightly, reducing their volume to -15 for each microphone in each channel, and using 1 ms delay for each as well. I also learned, annoyingly, that if you don't hit the return key each time you change a value in these fields, it does not remember what you typed when you click on the next field with the mouse.
3) With things a bit improved, but still a bit too precise, I played around with a bunch of the Delay settings – more about this in the next paragraph. Overall, these changes matched my real piano soundfield with my speaker set-up extremely well, better than any that I have used before.
Delay versus Reverb – I have never been quite sure how to think of delay versus reverb. Currently, for an acoustic instrument, I am thinking that delay represents reflected sound within the case of the instrument while reverb represents reflected sound from the room around the instrument. Since I am in a real room, and am not trying to pretend that I am in a concert hall or cathedral, I left the reverb turned off so that my room provides its own realistic reverb. The delay, on the other hand, seems quite good to simulate the sound bouncing a bit within the case of the piano from the broad soundboard before it exits to my ears. I ended up using a fairly short delay, 20 ms, as any more, and certainly more than 50 ms, sounded too much like an echo to me. I played with the mix from 0 to 100, and used 25%, as more sounded too round and too soft, and less was not enough of an effect. Since my piano has quite a bit of resonance to it, I added a bit of feedback, just 10%, which broadened the sound after the notes are struck to match how they sound on my piano. As for tone, I do not have a good feel for where this should be set. I ended up using -0.5, only because the far right was way too tinny and the far left was not very helpful. I would be interested to hear how other people adjust the settings in the Delay function to add realism and airiness (although I am sure that it is good for adding weird effects as well).
Soundboard modifications – I ended up sliding the impedance to the right, the cut-off to the right, and the direct sound duration to the left to simulate the long ringing tones that I get out of my piano. I also played with each of the overtones, seeing if I could get them to better duplicate the sound that I heard out of the acoustic piano. It is still not perfect, and my acoustic piano has a bit of a nasal-ness to it, coming on about half a second after the key is struck. I have not figured out whether it is an overtone correction or some other correction to make in the preset to duplicate this tendency a little better. There is definitely room for improvement here.
Hammer tone and hardness – I made various corrections to the hammer tone and the three hammer hardness settings, but I'm not quite happy with them. Unfortunately, the hammer hardness is adjusted stepwise rather than on a continuum. It would be nice to have a little curve for hammer hardness similar to the velocity curve, rather than three separate sliders.
Damper settings – I had not thought about this before, but one of the things that makes the Pianoteq presets not sound like my real piano is that my real piano dampers do not do a great job, especially on the bass notes. Perhaps a grand piano, with gravity assisting rather than a spring, does a better job. In any case, a little bit of whacking on the keys in the lower tones while adjusting the damper settings, both position and duration, gave me a fairly precise fit. Also, adjusting for the last damper was easy as well.
Unisons and out-of-tune-ness – it's been about eight months since my piano was tuned, so adjusting the unison width to 2.0 was necessary to duplicate the out of tune imperfections that I hear on my own piano.
Velocity, volume, and dynamics – as I mentioned, my QRS PNOscan provides for somewhat soft keyboard, so I have a convex upwards velocity curve. Also, as I enjoy the resonant sounds that you get by holding some keys down softly and then playing other keys of the same tone but different pitch, I have added a small toe-area to my Pianoteq velocity curve so that pushing the key softly enough does not launch the hammers. As for volume, I set the volume level so pounding on my X-key produces the same volume as pounding on the piano. From here, I adjusted the dynamics so that I get about the same touch and feel for light and heavy keystrokes on the real thing and the simulated thing. I have noted that a lot of people's presets put dynamics at about 40 – if I did that here, then I could never play as softly on the X-key as I can on my own piano. Therefore, I tried 60 which was too high, and settled on 50, which was about right. I'm sure that this varies quite a bit depending on the slope of your velocity curve.
Sympathetic resonance – I ended up pushing it just a bit to the right, to match a little bit more richness that I hear out of my acoustic piano.
Noises – I considered moving the sustain pedal noise and the key release noise all the way to zero, since I am sitting at a real piano that has a real sustain pedal and real keys. Instead, knowing that sometimes I play with this preset using the X key, I just left them where they were, as they are not too offensively loud.
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In any case, that's where I started, and that's where I ended up. The sun was high in the sky when I began, and it is long below the horizon at this point tonight.
- David