Topic: Spectrum profile technical question

Hello,

I have the intention to reproduce in Pianoteq the sound of my acoustic upright piano.
I've made some samples at good quality (44kHz, 16bit stereo) at medium and high velocities of various notes.

Let's take A4 at medium velocity as example (very low noise, no distortion).
Here's the spectrum profile (Hanning, size: 2048):

Fundamental: -1.3 dB peak
2nd harmonic: -11.1 dB peak
3rd harmonic: -17.3 dB peak
4th harmonic: -13.7 dB peak
5th harmonic: -28.5 dB peak
6th harmonic: -27.8 dB peak
7th harmonic: -30.7 dB peak
8th harmonic: -36.8 dB peak
9th harmonic: -37.1 dB peak

How exactly should I interpret this data to implement it under "spectrum profile" in the voicing section of Pianoteq? Should I have selected another method (Blackmann, Hamming, etc) or a different spectrum size?
Moreover, the numbers I get are way over the allowed program limits (+15 dB; -15 dB), and I can't set up decimal values. Should I round them up? (decimal values would be welcome though)

Re: Spectrum profile technical question

The values shown in the spectrum profile are relative values (that is, the difference between the default value and the current one), not absolute values. Thus it is not straightforward to do what you want. One way would be that using the same technique, you measure also the Pianoteq default output, and then compute the difference to program it in the interface. Example with your own data: suppose that your measure of the Pianoteq A4 gives you (I use the same normalization as you for the first overtone - as it is arbitrary):
Fundamental: -1.3 dB peak
2nd harmonic: -9.0 dB peak
then you should program in the interface
Fundamental: 0 dB
2nd harmonic: -11.1 + 9.0 = -2.1dB

Concerning the technique to use, there shouldn't be any problem as long as you use the same for measuring your piano and Pianoteq.

Rounding values is not a problem, 1dB is quite a small variation.

Re: Spectrum profile technical question

Thanks for the suggestion, with your method I obtained virtually the same sound as the reference file (even visually on the spectrum analyzer they seem the same).
Unfortunately, after modifications, almost all notes except the reference one (A4), even the ones immediately above or below, now sound very weird, with a feel of a very weird mix of a bell and a harp.

The original fxp file is this:
http://www.forum-pianoteq.com/uploads.p...remona.fxp

And I have applied these settings for the sound spectrum:
1: +1.7 ---> +2
2: -6.1 ---> -6
3: +6.3 ---> +6
4: +10.5 ---> +10
5: -0.2 ---> 0
6: +2.8 ---> +3
7: +4.1 ---> +4
8: +5.7 ---> +6

This is the sampled reference note (A4):
[deleted]

Last edited by s12a (19-07-2008 01:42)

Re: Spectrum profile technical question

Hmm... I should have warned you about that, sorry, there is no reason that the difference in spectrum between the two pianos remains the same for all notes. The solution would be to be able to modify the spectrum note by note...

Re: Spectrum profile technical question

That's too bad...
Yes, I was going to ask that: a custom sound spectrum for each note (or group of notes?) could be very useful to (almost) perfectly recreate the sound of an existing piano over default presets. I feel that global sound spectrum settings have many limitations.

I guess I'll keep my fxp as it is and wait for an upright piano add-on

Re: Spectrum profile technical question

Creating splits in Cantabile or another host that allows keyboard splits will let you get much, much closer to what you want. It's much easier than you may fear:

Try downloading one of the Cantabile splits files from the Files area here, and, assuming you have a pc, download the latest version of Cantabile lite (a freeware program), which will give you four splits, and then open the splits file in Cantabile. This way, all of the splits will be created for you. All you have to do is open each instance of Pianoteq, select the preset you want (you can mix and match presets), edit the partials and other parameters, and use "Save as" to save your new set of splits. You can end up with a 4-way keyboard split for all of the PianoTeq presets, each named to indicate that it's an "Erard 4-way split", or "M-1 Jazz 4-way split," etc. You just click on Open in Cantabile to open the file, which loads the file very fast, even though its opening four instances of PianoTeq.

I'm uploading a new split file today, called Songwriting Rock, since I'm too tired to think of a better name.

If the four splits aren't enough, the full version of Cantabile is only $25, which lets you have as many splits as your RAM will let you load. Be sure you get the latest version of Cantabile. An older version had a problem with splits. (I have nothing to do with the company that creates this progran, but Cantabile is a sweet little program that offers other features worth having, too, such as Autorecord, a favorites menu for presets, and the ability to autoload whatever preset you want to appear when you first start it. It also loads very, very fast--there's no 20 second lag while it scans your vst folder. Takes 2-3 seconds, even if your default preset is a 4 way split with extremely different settings in each split.)

All of this may seem cumbersome, but, actually, it will take you about ten minutes to download everything, install Cantabile, and then load the splits file. After that, your time just goes to making the edits in each instance of PianoTeq.

One caveat: with four splits, I don't have any increase in latency, but an edit will sometimes take a few more seconds to "take." In other words, if I lower the amount of body resonance, I will often have to wait for 2-3 seconds before making another edit. Nothing terrible: the interface appears to freeze, but all that's happening is that Cantabile is taking those few seconds to save the new parameter setting to a temp file. To reduce this time, close the instance of PianoTeq and save the file in Cantabile again, and then reopen the instance of Pianoteq. Takes 2 seconds.

More generally, for getting the sound that you want, you may want to experiment with having both varying partial settings in each split and varying EQ settings. (Remember that the EQ settings affect the sound before any other parameter, including the partial sliders.) Thus creating notch filters or exciters in the EQ area can have as much of an effect, or more, on the amplitude of specific frequencies as the partials settings. The EQ settings are of course universal, but only within each split, so they offer much control.

I'm aware, of course, that even this arrangement won't give you the ideal: the ability to control each partial on each note. However, using splits, eq settings, and the partial sliders together does take things into new areas of realism.

Sorry for the long post. I'm sure that other people here will have other suggestions about working with splits.

Last edited by Jake Johnson (19-07-2008 18:29)

Re: Spectrum profile technical question

Thanks for the detailed explanation, but since I like to change instruments in Pianoteq often and to keep things simple, maybe that's too much for me
And besides, I think that 4 instances of that program would be insufficient for what I want to do.

Re: Spectrum profile technical question

Well, I guess you won't be interested in the new Sequin Resonance settings for my upcoming Liberace.fxp, then.

Regardless, to open a set of splits in Cantabile, you just open a single file. As I say, you can't create note by note renderings of a given piano. But just having four splits, with two in the midrange, gives you much more control over the timbre across the keyboard.

I do want the ability to set the partial amplitude for each note. I worry that achieving this may be impossible, although I think it will be possible, since each setting would become a constant for each note.

Cheers.

Last edited by Jake Johnson (21-07-2008 23:08)