Loop tuning...

[alfaholic]

Hello everyone...

I know this topic is more for Korg developers, but I hope someone will hear and make some progress in this area.

Here is some short video of making loops for samples:

https://youtu.be/DakW_CPzxK4

I can create many different loops, but most of the sounds we hear in Romplers are made usually with One Cycle Loop, which is shown in this video.
In order to achieve the smallest files as possible, One Cycle Loops are the best. They can not work with everything, but many sounds can be looped this way.

The problem with sampling and creating One Cycle Loops for Korg Pa (and other Korgs as well) is the it can read the loops from the files, but can not read loop tune, which is very important.

It would be great if developers could give us this option, because all modern samplers can tune sample loops.

[AntonySharmman]

One Cycle Loops aren't the best option of a sound developer , I'd say an outdated method even in limited size Nand Flash memories !
This method is only used in pure waveforms with proportional frequency period , can be used to loop single synths oscillators like
transistor organs and pure stings oscillation but can never be used in modulated oscillators and especially in vintage instruments
that even you could achieve a short tuned periodic portion , the resultant is always pure and fake when inserting in loop portion !

It's true that PaSeries do not have loop portion tuning feature like e.g. Kronos but it's also pointless when in a natural instrument
a played note varies pitch in time axis during oscillation and loop tuning in this case is a completely fake artifact !
I'm aware of limited Ram size in PaSeries in my developments but I use some other advanced techniques to emulate natural note
duration/looping and never sacrifice good loop quality on the altar of greed of "all sounds" in my commercial collections.

A Pro sound developer always use external Mac/PC utilities for shaping , tuning looping portion and loop samples with advanced
looping algorithms like in Redmatica Keymap / Autosampler / ESC / EXS24 / Kontakt and some special sound editors for the rest
workflow of sample timbre processing , always using specific settings, curves and parameters according to the looping case !

Professional Stereo Looping is a state of Artwork !

[alfaholic]

As you said it is a state of artwork, and I agree. But, even One Cycle loops are outdated, they are still the best way to loop basses, rhodes, electric pianos, and get smallest files possible.
You can do it in many ways, but there is no need because one cycle is just enough, nothing will change if you use longer loops in those kind of instruments.

[AntonySharmman]

they are still the best way to loop basses, rhodes, electric pianos, and get smallest files possible.
You can do it in many ways, but there is no need because one cycle is just enough, nothing will change if you use longer loops in those kind of instruments

I tend to disagree in that , since even the simplest waveform of a pure bass guitar instrument has subsonic harmonics that
are not covered using this method if we want to be accurate in a real reproduction of bass instrument !
Of course nobody will ever notice that in a style with 8 track instruments but when bass leads in an acoustic style with
guitar and Pad , especially when glissando expression is used , then the lack of naturalism will be very obvious !

I always use maths using Fourier Analysis and Synthesis in waveforms but I can give a simple example why one cycle loop is insufficient !
Let's define a central F0 frequency of a bass note , let's say 200 Hz , if we use :
- 200Hz loop then we can gain all even harmonic frequencies but we will loose all odd / fractional (like 5/8 λ) / and all subharmonic.
- double cycle loop (100Hz) we will loose all odd harmonics and sub-harmonics plus all fractional harmonics... ect ...
For instance in your Redmatica Keymap utility , those algorithms are used by default but you have to determine the right parameters
for every instrument and every single sample !
(By the way if you try central frequency loop with a sampled multilayer F.Rhodes , this will be the disaster of your samples ...)

Conclusion ... we must be aware of physics of any type of instrument we want to sample , we must use frequency spectrum
analyzer in every single sampled note , calculate curves and the mean root frequency equation of periodic portion that can include
all those generated frequencies that is not definately a simple cycle loop !

Applied technology will dramatically change in the next 5 years in keyboards , where 10 Gb will be a reasonable size for
custom PCM samples , short samples with cycle loops will be out of question and all sound developers are already focusing
in velocity multilayers , round-robin feature (I was the first that introduced that in Kronos libraries) and full smart articulations
in native instruments emulation , targeting at VSTi Production development level , applied in workstations.