I've been looking over the specs for some older keyboards lately, and found that back around 2000, Roland was offering a feature in which there was a slower attack on soft samples. In other words, the softer the strike, the slower the attack stage of the ADSR envelope. (Attack was modulated by Velocity.)
Does this make any sense? Ive seen the sample start modulated by velocity, but not the attack. Standard stuff that I missed?
It is not unusual that synthesizers are capable to modulate the Attack time (or speed) by velocity, and this is true for sample players, too. In Apple's LOGIC there is a sampler named "EXS24" having this feature.
No, no. I understand that samplers can modulate the attack and much else with velocity. I was asking if it made sense to do so for a piano multisample, such as the ones on the old Rolands.
I guess it would have a similar effect to modulating the sample-start by velocity. Slowing down the attack would mean that the loudest part of the strike would play at a low volume on soft strikes.
I see. I think it does make sense. A harder strike is a faster strike. Although with multiple samples this will implicitly occur because the attack parts of the samples contain the envelopes for different velocities, it might refine the effect since there aren't 127 different samples for 127 different velocities.
To me, modulating the sample's starting point by velocity doesn't make too much sense, it will cut the most interesting part of the attack phase in many cases.
On the other hand, what timeframe are we talking about? How slow can the attack phase of a piano sound be? I think fiddling with samples is a complex task and many approaches come into question to get a consistent sound and behaviour through the velocity space.
On the other hand, what timeframe are we talking about? How slow can the attack phase of a piano sound be? I think fiddling with samples is a complex task and many approaches come into question to get a consistent sound and behaviour through the velocity space.
Yeah, that's what lost me, too. On a piano, once the key forces the hammer to lever forward and strike the strings, the note sounds, so on a midi keyboard, triggering Note-on should sound the sample immediately. An increase in velocity shouldn't matter, since the increased key velocity itself will mean that the key triggers the Note-on faster.
Still, here's a description of the feature from the manual for a Roland KF7:
Changing How Rapidly Sounds Are
Expressed According to the Force
Used to Play the Keys
(Hammer Response)
You can adjust the timing with which sounds are produced
according to the force used to play the keys. This function is
called “Hammer Resonance.” (sic)
When a key is pressed on an acoustic piano, it causes a
hammer to move and strike the strings, producing sound.
The hammers move more slowly when the keys are played
gently, meaning that sounds are produced just slightly later
than when you play the keyboard with greater force.
When the Hammer Response function is on, the interval
between the time a key is pressed and the time sound is
produced varies according to the force used to play the key.
The more gently the key is pressed, the more delayed the
timing of the sound.
Touch <ON> to turn the Hammer Response function on.
Touch the screen slider to adjust the time it takes for a key to
sound after it is pressed.
The more the slider is moved to “Slow,” the more delayed
the sound is when the keys are played softly. Conversely,
sounds are produced more quickly when the keys are played
with greater force.
It seems to be controlling what might be called the efficiency of the action in a real piano. The only thing that I can imagine is that the timing increment is changed very, very slightly. Otherwise, there would just be a strange delay on soft notes. (??) But Roland must have felt\heard that it made a difference. At the time, at least. I don't think I've seen this feature listed in more recent digital instruments.
Reading the manual's text, I see there are about three terms we're messing about.
The more gently the key is pressed, the more delayed the
timing of the sound.
So the manual talks about a delay that can be modulated. The start of the sound is being delayed dependent on the velocity.
The starting point of the sample stays most probably the same. I say this because some samplers can in fact cut into a sample at a later point dependent on modulation sources, but this is not the case here.
And lastly, the "attack" parameter of synthesizers or samplers controls the time how long the sound rises from zero to maximum volume. A piano sound has a short attack, and the attack phase starts when the hammer touches the string (while the delay mentioned in the manual takes place before the hammer touches the string, i.e. before the attack phase).
However, the attack time of a piano sound is not zero as the sound develops, and this may be influenced by the time how long the hammer touches the string and how long the mechanical pulse on the string needs to spreaden to a smooth movement. So a slight variation of how soft the sound comes in (in the order of milliseconds or even fractions of milliseconds) may be useful.
Now we come to the question if there is some noise from the hammer mechanics before the hammer hits the string and whether or not this is important... But count me out.
Mmmmh, I'm not convinced on this.. There are two variables that make me feel the thing a little strange.
First one the escapement: the key is not directly connected to the hammer so there are situations where the hammer could it the string before the key reaches the keybed and situations where you can 'shot' the hammer with minimal key movement without even reaching the keybed at all (I know is rare but possible).. Impossible to recreate without optical sensors in a digital piano..
Second one: latence.. I think that latence, even in the best situation, is in any case longer then your softest strike on acoustic piano..
Just my thoughts..
Mmmmh, I'm not convinced on this.. There are two variables that make me feel the thing a little strange.
First one the escapement: the key is not directly connected to the hammer so there are situations where the hammer could it the string before the key reaches the keybed and situations where you can 'shot' the hammer with minimal key movement without even reaching the keybed at all (I know is rare but possible).. Impossible to recreate without optical sensors in a digital piano..
Second one: latence.. I think that latence, even in the best situation, is in any case longer then your softest strike on acoustic piano..
Just my thoughts..
No one has to be convinced of anything. There are physical limitations of electronic keyboards and many approaches to overstep them. Optical sensors and an intelligent interpretion of what they deliver is one option, real hammer mechanics and electomagnetic or piezoelectric impact sensors are another. Most keyboards just measure the time it takes from one dedicated key position to a second one, and additional hammer-like mechanics give the feel there is a real piano keyboard. In any case for MIDI the result has to be one value that contains the velocity (and the note number it is valid for). The keyboard's construction may or may not introduce a velocity-dependent delay.
And there is a sound generator that has to deal with the single velocity value for a given note. There is no continous key position being transmitted, just the information "there was a note event, key x, velocity y. It's your turn." The most useful approach to interpret this information is dependent on how the keyboard works. BTW this sort of problem is even more present for note-off velocity.
My conclusion is, if any synthesizer or sampler has such parameters and you are interested in using them, try yourself what works for you. Don't forget your mind, your nervous system and your adaptiveness are parts of the system, too!
Addendum: A real piano is a very much MIDI-like system in a way... You move a key, the mechanics convert the key motion into a single value (the Hammer's speed when it escapes the plunger), and this single value is transmitted to the string: "Here I am, someone hit my key, and this is my impetus, bang! It's your turn."
I agree with Jope: it appears quite clear to me that the "Hammer Response" described in the manual adjusts the delay between pressing the key and the sounding of the note, without adjusting the envelope of the note.
Greg.
Assuming that note-on is triggered when the key bottoms out, it seems odd. One thought--it might have let the user control how repetitions sounded, and how soon a repeated note replaced the first sounding of the note. In any case, the feature seems to have disappeared from Roland's settings for more recent keyboards.
In any case, the feature seems to have disappeared from Roland's settings for more recent keyboards.
Probably they weren't convinced, too
Well, I take that back. The same feature is in Roland's new piano, and the same description of it appears in the manual. It's distinct from the "Touch" feature, which is listed on another page.