• Register
  • Help
Page 1 of 3 123 LastLast
Results 1 to 10 of 25

Topic: More about volume/velocity modulation in samplers (+ focus on K2 piano lib)

Share/Bookmark
  1. #1
    Senior Member
    Join Date
    Jul 2005
    Location
    Paris, France
    Posts
    310

    More about volume/velocity modulation in samplers (+ focus on K2 piano lib)

    Ok, this gonna be a long post... (don't worry, it's gararanted 100% free of sympathetic resonance : only basic stuff)

    Where everything begins :
    Who have ever experienced some kind of deception when moving their favorite piano library from their native giga format to kontakt ?
    You know, not the same touch and feel ?

    The explanation :
    SOS has published an interesting study in their second DVD about midi velocity sampling accuracy. You know what ? samplers behave VERY unevenly. Bottom line is : only EXS provide the most natural response (ie linear decibel curve in the 40dB range) needed to reproduce acurate acoustic performance (according SOS).

    The biggest discrepancies are in the lower velocities.
    (*table removed* see SOS study for more information)


    Focus on GS and Kontakt :
    - Default GS curve (H dyn. non linear) is slightly convex and provide only 30dB total dynamic.
    - Default Kontakt curve is very concave and very steep in the lowest velocities (drop to -85dB for velocity=5, assuming velocity 127 is 0dB)

    So, it's quite obvious know why my favorites pianos (sampletekk...) don't behave the same in Giga and Kontakt.
    This discrepancy can partialy be corrected by reducing the percentage of global volume modulation in Kontakt, but at the expense of over-compressing the f-fff zone (which is already compressed on some sampletekk patches, you know, the ones where top layers are stacked at the very top)


    The cure is a curve :

    Yes ! A custom curve to load in Kontakt2 volume/velocity modulator : download here >> CURVE <<

    Store it in : preset/tables/velocity curves

    Load it here :




    This curve works very well with all sampletekk piano : it gives an almost linear volume/velocity response. It may work also very well with other libraries, translated from Giga to Kontakt.

    Look at the result with TBO (Db x velocity) :



    TBO 35 dB linear response in achieved by loading the curve and setting the global modulation slider at 92%. You can play with this slider to adjust the global dynamic you want, still keeping the linear behavior.
    85% = 30dB dynamic
    92% = 35dB dynamic

    Oh, yeah, by the way, VI like Ivory provide also such a perfect linear Db response to velocity you can adjust with the dynamic range knob...


    Well, using this curve with sampletekk pianos (and I'm sure other, I had some good result with vintaudio ones for instance), you can enjoy a more accurate timbre x volume relationship.


    Some additionnal thought about tweaking velocity :

    Keyboard velocity :
    Starting with a correct timbre x volume behavior is a first step. Don't forget you have also to adjust your keyboard velocity response, which is a totally different thing. If you have already done that before applying the correction I have described, you may have to make some slight adjustment.

    Samples mapping :
    Still working on sampletekk piano, with my correction curve, I have the feeling that patches where layers are evently spread are the most accurate from a timbre/volume accuracy point of view. Assuming you can tweak your keyboard response to control well this mapping, then it's the more true to the real thing.
    (remember : this deserve a very hard keyboard strengh setting ! TBO latest layers should only be reached when playing one strong note with the strongest finger, with no chance to trigger it when playing a 3 notes chord for instance)
    That's not means that other mappings are without interest ! Stacking highest layers at the very top have some good effect, like making the piano warmer while compressing the highest velocities (and then making the perceived timbre evolution stronger in this zone). I encourage everybody to make their own mapping, you can really tweak you piano from an old shy classical moonlight serenade piano to a ragtime-able killer.


    Well, I hope this help,
    Enjoy and share your comments !

  2. #2

    Re: More about volume/velocity modulation in samplers (+ focus on K2 piano lib)

    Holy cow, this is brilliant Laurent - I just spent some time last night on getting the velocity right for my playing and this will certainly help me further.

    Thanks for taking the time!!

    Len

  3. #3

    Re: More about volume/velocity modulation in samplers (+ focus on K2 piano lib)

    Why would you want a linear reponse of dB to velocity? There certainly isn't one on a real piano. Nor would this correspond to a linear volume/velocity relationship, since volume has little to do with level, except that they generally go in the same direction (i.e. an increase of level usually corresponds to an increase of perceived volume)

    A generalisation often used is that an increase of 6dB corresponds to a doubling of volume, but this is extremely rough and ready. It also varies massively with frequency. Perceived loudness also varies with frequency (have a look at these loudness curves http://hyperphysics.phy-astr.gsu.edu...nd/eqloud.html ). According to these curves a sound at 50Hz and 60dB is only perceived as being as loud as a 1000Hz at 20dB. So why would you want all your 60dB samples assigned to the same velocity?

    I think a great way to organise piano samples would be to use one of those Yamaha boxes that clips underneath a normal piano keyboard and uses infrared to detect the velocity with which notes are pressed. You could record the velocity of key depression next to the name of each sample, and then assign that sample to a similar velocity in the soft-sampler. At least this would ensure behaviour close to the real piano.

  4. #4
    Senior Member
    Join Date
    Jul 2005
    Location
    Paris, France
    Posts
    310

    Re: More about volume/velocity modulation in samplers (+ focus on K2 piano lib)

    This curve has absolutely no effect on relative loudness across keyboard or frequency spectrum. The TBO output graph exemple is made with middle C note.

    Please note : It's only a trick to rectify the velocity modulation bias due to giga to kontakt conversion.

    The "linear" reference is more a sampler thing to facilitate the mapping of normalized samples. It's not directly correlated to actual piano response.

    Beside theory, my observation is that my sampletekk pianos react better with this tweak, which is the only important thing to me...

  5. #5

    Smile Re: More about volume/velocity modulation in samplers (+ focus on K2 piano lib)

    OK, sorry, I misread your original post.

  6. #6

    Re: More about volume/velocity modulation in samplers (+ focus on K2 piano lib)

    Hi Laurent and thank you so much for all this info. I do appreciate your support.

    Cheers!

  7. #7

    Re: More about volume/velocity modulation in samplers (+ focus on K2 piano lib)

    Laurent did you notice the (c) SOS Publications Ltd. 2005. All Rights Reserved on the back of this CD Rom ??? You need to obtain permission before reprinting any portion of an article.

    FYI I wrote that article.


    Ernest Cholakis
    Numerical Sound
    www.numericalsound.com

  8. #8
    Senior Member
    Join Date
    Jul 2005
    Location
    Paris, France
    Posts
    310

    Re: More about volume/velocity modulation in samplers (+ focus on K2 piano lib)

    Quote Originally Posted by Ernest
    Laurent did you notice the (c) SOS Publications Ltd. 2005. All Rights Reserved on the back of this CD Rom ??? You need to obtain permission before reprinting any portion of an article.

    FYI I wrote that article.


    Ernest Cholakis
    Numerical Sound
    www.numericalsound.com
    I apologize for that. Only the sampler dB comparison table was taken from SOS.
    It was only illustrative for my point : I have removed it.

    BTW : great article.

  9. #9

    Re: More about volume/velocity modulation in samplers (+ focus on K2 piano lib)

    Quote Originally Posted by Laurent
    I apologize for that. Only the sampler dB comparison table was taken from SOS.
    It was only illustrative for my point : I have removed it.

    BTW : great article.
    Oh come now, that is no different from a newspaper printing a graph showing price movements and attributing its source. I would be extremely surprised if SOS mag, of all people, got angry about it (so long as you mentioned it was from SOS). They are nice folks.

    And thanks again for this - I tried it last night and it seems to work well. Only question is, I can't really tell the difference between this velocity curve and the one you suggested previously by using the Script Editor/Utilities/Comp-Exp route?

    Cheers

    Len

  10. #10

    Re: More about volume/velocity modulation in samplers (+ focus on K2 piano lib)

    Hi Laurent,
    thanks for all your work on this.
    Right now I'm a little bit confused though, since Worra just released an update of TBO for K2.
    Would it still be benefical to use your volume rescaling with the updated TBO do you think?

Go Back to forum
Page 1 of 3 123 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •