Hello berghs.kedjan
I do understand the effect you have described on a real grand piano. To state my understanding, I describe it as the sound growing (seemingly all out of proportion) much larger than what is attainable in a digital instrument in general, and Pianoteq in particular.
Let's discuss what is happening in a real piano, and then show why this is not readily attainable in the digital/electronic world, shall we?
The sound-producing capability of a real grand piano rests upon two resources: 1) the tremendous potential mechanical energy contained in approximately 230+ steel strings, each stretched to 200+ pounds; and 2) the physical size of a grand piano's soundboard is multiple times larger than even the largest home/studio speaker system.
There is a third restriction, not of the physical piano, but that of the digital medium wherein digital instruments' signal amplitude literally runs into a wall (namely, all of the 16 or 24 bit digits are all set to 1) -- one cannot generate larger sound in digital than the maximum electrical signal described by all 1's in 16 or 24-bit code.
Also, there is a fourth restriction, that of the analog reproducing system not being able to LINEARLY amplify the dynamic range equal to that of a real grand piano, without some form of compromise in the sound -- either in the amplifier running out of power, or the speakers running out of displacement.
Let's discuss each of these topics separately:
The (potential) energy stored in highly tensioned steel piano strings arrives from some 230+ steel strings each loaded with over 200 pounds of tension. A grand piano's frame literally must support close to 50,000 pounds (25 tons -- nearly 22,700 kilograms) of tension, BEFORE a single hammer strikes a string. It is exactly because of this high tension that hammer-struck strings are able to create such loud sounds, and maintain their resonance for up to several dozen seconds if left undamped.
This energy of vibrating strings is transmitted to the piano's soundboard by means of the two bridges. The physical surface area of a grand piano's soundboard is many, many times greater than the surface area of even the largest home/studio speakers.
The above two paragraphs describe why a grand piano is capable of producing a huge sound if the dampers are released, and one plays rolling bass tremolos of the type you described. The dynamic range of a real grand piano may be in excess of 60 decibels from the softest to the loudest noises it is capable of producing.
Now we must consider the nature of what 60 decibels means in terms of electronic equipment required to produce such a wide dynamic range. An almost unnoticeable change of 3dB requires a doubling of amplifier output, between any starting loudness and a resulting 3dB larger loudness. This is true whether the starting sound goes from 60 to 63dB, 92 to 95dB or 121 to 124db.
Before this gets too technical (and possibly boring), let me state up front that being able to reproduce a 60dB dynamic range of a piano requires an amplifier and speaker system that can handle a MILLION times swing in output signal! If we can agree that 3dB change requires the amplifier to double its signal, that a 6dB change requires an amplifier to quadruple its signal, and a 10dB change requires a tenfold increase in signal amplification --- then a 20dB change requires a one-hundred fold increase (tenfold x tenfold), a 30dB change requires a one-thousand fold increase, a 40dB change requires a ten-thousand fold increase, a 50dB change requires a one-hundred-thousand fold increase, and a 60dB dynamic range requires a one-million fold increase in signal output.
Now, how many of us have computer speakers, home stereo systems or studio monitors that can handle a million times swing in input voltage? My personal studio has three professional amplifiers that total 2000+ watts per channel at <0.1% distortion, but my speakers would be fried if I were to attempt to feed them full power. Besides, a speaker system has a fixed transducer area that can only be displaced only a fixed maximum amount.
Restated, an amplifier/speaker combination "runs out of gas" in attempting to duplicate the dynamic range of even a moderately sized grand piano.
Yes, I hear you .... what about all of the 144db theoretical range of a 24-bit digital system? Well, friends, that is a theoretical limit based on the mathematical calculation. In real life, a the sound of a single grand piano can be instantly told apart from even the finest home/studio reproducing system.
In summary, the sound of a single grand piano whose 230+ strings tends to "grow" when a pianist performs a bass note tremolo with the dampers raised, and additional strings join in on the sympathetic resonance. In contrast, a set of speakers can only do one thing: move to and fro. When you attempt to play many notes through a stereo system, the sound literally "collapses", whereas the sound continues to grow when playing a real piano.
I also imagine that many of us have electronic systems that can reproduce a 60dB dynamic range. Fair enough -- they can get louder by 60dB BUT I doubt they can reproduce the 60dB (or one-million fold) change in signal input without seriously distorting the sound. Want proof? Just realize that THIS is why even the finest stereo system has a difficult time sounding UNMISTAKABLY similar a single grand piano!
(By the way, this 60dB swing in signal is precisely the reason that many commercial recording studios apply compression and/or limiters to their CDs. If they didn't resort to some form of compression/limiting, the resulting sound would be too soft in the soft passages, and simultaneously too loud in the loudest passages. Customers would be constantly adjusting their volume controls -- distortion, not withstanding.)
I hope this was food for thought.
Cheers,
Joe
Last edited by jcfelice88keys (14-05-2010 04:53)