Research On Piano Sample Instrument

Some of the consideration that definitely need to take into account things like sample rate and bit depth, looping. spatial relations, number of notes that needed to be sampled, sampling dynamics, sampling others effects, polyphony, the pedals sound and effects (reverb). All this steps can not be avoided in order to build a nice sound and realistic piano sample instrument.

Sample rate and bit depth

Many decisions need to be made for recording piano sample and most important one could be the sample rate and bit depth. Since the sample rate is the number of time that the original sound is sampled per second so the sample rate of 44.1 kHz mean that 44100 Hz per second were recorded. If  the sample rate is too low the distortion know as aliasing will occur and will be audible when convert it back to analogue. The bit depth used to describe the number of bit that available in a byte. More bit depth mean better quality but bigger file size. So, for this project I used 24 bit and 96 kHz for recording and bounced with 44.1 kHz to reduced the file size and maintain the audio quality.  

Looping

Many sample instrument builder used a lot of this techniques in order to reduce the file size since the samples set for the instrument can be big so by using this techniques will reduce the file size. Looping is the technique that selecting a short duration of the sound that remain unchanged over a period of time, and repeating it over and over the volume level is reduced. According to what  CRAIG ANDERTON said from Sound on Sound:  

- "Pianos are percussive instruments, with envelopes that decay over time. As a result, unlike a wind instrument or organ, there's no steady-state, constant-amplitude portion of the signal that would allow for a long forward or crossfade loop.

-The envelopes take a long time to decay. Therefore, unless you have humongous amounts of internal memory, you will not be able to fit several samples with natural decays into a sampler, thus making looping a necessity.

-Given all this, it seems that grabbing a single-cycle loop as close to the end of the waveform as possible would give the best results.  

 Spatial Relations

Since the acoustic piano have the bass end and the treble end it is essential to preserve this spatial relationship by using the stereo recording techniques.

Number of notes sampled

It is necessary to decide number of notes to be sampled since the piano has 88 keys and in my case I sampled all of them. By using Kontakt not really necessary to sample all key but does not sounding realistic.

Sampling Dynamics

In Kontakt, it is allowed by using just one layer of velocity but it's sound unrealistic. Therefore, it is important to record three to five set of dynamics so the more velocity layer we have the more the piano instrument will sound real.

Sampling others effects

Most sample piano instrument has additional types of samples aimed at capturing more of the nuance of an acoustic piano, things like string resonance and damper effect. String resonance is related to the strings' overtones. Each of the overtones generated by a vibrating string are at, or close to, the fundamental frequencies of higher notes whose frequencies bear a mathematical relationship to the one played. This results in a weak sympathetic or resonant vibration of the strings of the related notes, and adds another dimension to the sound. Damper-effect samples are triggered by releasing a key, and add another subtle dimension to the piano sample instrument sound. For this project, due to the time constraint of the studio and also to save some token for other project we could not simply record this kind of effects but being said that we can still get this kind of effects from Kontakt and this it where the script come in to rescue and will discuss this later.

The Pedals

Since acoustic piano has three pedals and it is necessary to record the sample sound for the pedals effects. But in my case, I am going to use just one set of sample sound then using the Kontakt to manipulate the effects by using the script.

Effects

In order to make the sound rich and realistic it is necessary to create some effects for the piano instrument and the most popular one is the reverb. Since Kontakt already has the convolution reverb so we just have to script it.

Above all, top branded piano sample like Garritan Steinway and Quantum Leap piano they all have some command articulation such as Lip position, mic position, stereo spread, velocity curve, sustain pedal and convolution reverb. With all these the user can simulate the effect of the real acoustic piano and make the instrument more realistic. For example: the stereo spread effect can make the stereo image wider, the velocity curve allow the user to alter the shape of the velocity range so the high and low velocity can be adjusted within the range. The convolution reverb let the user select the reverberation of the room with the impulses recorded.

                                    Figure 1: Garritan Steinway Piano Samples Instrumen

                                       Figure 2: Quantum Leap Piano Samples Instrument

                          Figure 3: EastWest's Studio Recording the Quantum Leap Piano Samples