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peter_schwartz wrote:

Kevin Nolan wrote:

peter_schwartz wrote:No, you can't equate MIDI velocity steps to dB.

Actually I think you can because the volume level increases with velocity relate directly to loudness of a piano.

Sorry Kevin, but no, you can't. First of all...

1) which piano are we talking about? A studio upright? A 6' grand? 7' grand? 9' grand? Which maker? My point here is that there is no standard for piano by which gradations of loudness are measured. Similarly, there are no standards for calibrating loudness on dB meters for which a piano of any kind is used.

2) what you and I perceive as volume increases in acoustic instruments are not just volume increases. They're increases in volume AND harmonic content (brightness). The ear, being more sensitive to higher frequencies than lower frequencies, will translate (in your mind) a brighter sound (with increased high frequency content) as "a louder sound". So if we played a low C on (any) piano at mF and then again at forte, you and I might agree that the forte note sounds 2x louder. But on a meter it wouldn't show that. It might be 1.5 times louder. That's because the extra brightness produced by striking the note harder gives us the perception that the sound has increased in volume by 2x. But if taking about dB's, it hasn't increased by 2x.

3) The resolution of MIDI velocity itself has zero -- I repeat, zero -- bearing on the dynamic range of any sound. If you're interested to know why, post back and I'll explain.

Peter - I'm fairly sure you're wrong on this. Let's forget about quality for a minute and just on what MIDI Velocity value increase means for, say, a sampled piano - the VSL one for example.

I'm sure that when VSL sampled this piano, they sampled each of the 128 velocity levels at a different loudness across the piano's loudness range. In other words, greater actual keyboard stroke velocity maps to the piano loudness. So they are mapping 128 MIDI Velocity values to what the piano has been designed to do louder over 128 steps from (probably) pppp to fff (or ffff) ie - sound louder. So although MIDI velocities are a linear scale, they map to the logarithmic scale of loudness -including the harmonic increases, ( as you say - part of what it means to be louder). It has nothing to do with the kind of piano or about you and me - loudness is not a percpetive scale per say - it' a straight forward difference between sound pressure levels and is independent of the listener. You are correct in indicating a perceptive element to this however, in that we can perceive something to be loud even if its volume is low (as in replayed at low volume or if heard at great distance - attributes such as envelope and harmonic brightness can tell us that it is being replayed at a loud level for that instrument even if we do not hear it loud there and then). But this is not directly related to our issue here - because even if you play back the VSL sampled piano at low volume on headphones, the 128 MIDI Velocity levels still match to the loudness levels originally sampled, giving you the correct sense that the loudness dynamics of the piano have been correctly captured.

In essence, it's the worldwide accepted standard of what a piano is and what a quiet and loud piano means that they have mapped that to MIDI velocity levels. They certainly have not mapped the 128 MIDI levels to linear sound pressure increases, so i thas to be a map of loudness.

This is related to why, for example, we can perceive an orchestral mock up as being validly loud if it uses samples of instruments sampled loud (and when replayed even at low volume) and why a sample orchestral mockup can sound wrong even at high volume if it's meant to sound loud but uses samples of instruments that were originally sampled quiet. This is particularly important to brass samples - you cannot achieve convincing brass mockup performances by playing soft samples loud - you need to sample the instrument at many loudness levels and attach each one to a velocity or CC controller level. Hans Zimmer did this famously for his brass in his original LSO sample set where the French Horns 'open up' louder as you move the modulation wheel - where different sampels at different loudnesses are invoked (I know this because I got temporary use of a version of his original orchestra sample set once !! )

It's also, by the way, why the SY77 and SY99 RCM synthesis is so incredibly acoustically convincing - by convolving FM with samples, you can use the harmonics in the FM sound to harmonically brighten a PCM sample as you hit higher velocities or change CC values, making it sound louder in a very acoustic way - it works fabulously on brass and woodwind instruments (the SY99 French Horn is amazing in this way). Here, albeit in the pure synthesis domain, loudness as we understand its associated characteristics (such as harmonic brightening) can be implemented through RCM synthesis and with loudness mapped to MIDI Velocity values! I haven't gotten into it enough yet but there may be a chance that MOD-7 can provide for this too.

In any case this is not the central debate - rather I still believe the point is valid that thousands of gradation steps in velocity sampling and available MIDI velocity levels are needed to deliver superior nuanced pianos that will approach achieving 'acoustic tone' in playing. That nuance has to be captured digitally because we notice it in the real world and 128 levels doesn't even begin to approach the required resolution, even with smoothing algorithms and velocity cross fading - those are not sufficient.

Kevin.

kevin, kevin, kevin. And: Kevin.

Are we so carried away by the need for supporting our own thesis,

that we don't remember page 1 of the "Manual for Snappy Answers to Silly Newcomers in Synth Forums"?

id est:

"no, you moron: MIDI has NOTHING to do with the audio domain"?

Loudness is a concept belonging to the audio domain.

There's NO effing correlation between midi velocity and loudness.

Ozy - I've just edited my post above yours and again - the 128 MIDI levels is just a map - but it IS a map to loudness when it comes to sampled pianos in particular. Pehaps with synthesizer sounds your right, but with sampled pianos it has to - it's the only means of dynamic articulation. Read my (improved) post again. I'm 100% confident of this point (but as pointed out it's not the central point to this thread).

IMO it would be nice to have more than 128 steps of resolution in my piano sound. Yes as velocity increases the piano gets louder but more importantly the tone begins to change. Controlling amplitude is simple but physically resolving those tiny shifts in tone beyond 128 increments across 88 notes seems impractical from a sampling POV.

Devnor wrote:IMO it would be nice to have more than 128 steps of resolution in my piano sound. Yes as velocity increases the piano gets louder but more importantly the tone begins to change. Controlling amplitude is simple but physically resolving those tiny shifts in tone beyond 128 increments across 88 notes seems impractical from a sampling POV.

so now we're saying that "128 steps of velocity is enough, and the problem is 128 levels of sampling".

my comment is:

a) welcome. I've been saying for days that the problem lies in sound engines, not just in keys (albeit the analogue-to-midi conversion flexibility issue is interesting).

b) forget about 128 sample layers: physical modeling will get there LONG BEFORE technology allows for 128 sample layers.

(of course at this point of the phantasy we are talking about 128 layers PER NOTE. what's the purpose of sampling each micro-step, if you then transpose a C to a C# which is played with a totally different key?).

It's one of those cases were you don't go on adding layers of steel plates to your wooden steam boat with 60 feet guns and bigger and bigger steam engines to make it slowly move.

You build from scratch a diesel cruiser with 10 feet missiles.

Devnor wrote:IMO it would be nice to have more than 128 steps of resolution in my piano sound. Yes as velocity increases the piano gets louder but more importantly the tone begins to change. Controlling amplitude is simple but physically resolving those tiny shifts in tone beyond 128 increments across 88 notes seems impractical from a sampling POV.

Just to be clear... it's 128 increments available across *each* of the 88 notes. And they don't all get sampled. Each note is sampled 8 times; the other 119 levels are interpolations. (I know, that adds up to 127, not 128, but zero=silence.)

(If you're talking about keyboards other than Kronos, notes are typically sampled only 1 to 4 times rather than 8, and usually most notes don't get sampled at all.)

StephenKay wrote:

Scott wrote:I think I have an actual answer here, instead of all this guessing.

On page 372 of the Korg M3 parameter guide, it shows that the M3, at least, supports both kinds of velocity mapping. A velocity curve can be applied either PreMIDI or PostMIDI, that is one of the programmable parameters.

Since Korg supports that on the M3, I assume they will support that on the Kronos.

This was discussed about 5 or 6 pages ago....

Indeed it was! I should have just pointed ozy to your post!

(It's funny, when you read a comment that you think is wrong, you always look at the following posts to see if it's been addressed, but you don't think of looking at the earlier ones...)

Kevin Nolan wrote:Peter - I'm fairly sure you're wrong on this...

Yes, I'm wrong and you're right. No point in my replying to any more than what I quoted above, because to do so would be futile, being that you're so right and all.

Wait... like a shadow person in my midst, there's one thing I couldn't help but see out of the corner of my eye -- (damn peripheral vision!) -- your repeated use of "128 MIDI Velocity values". So I'll comment on that because here's something that cannot -- cannot -- be disputed.

There aren't 128 velocity levels. Really now, can we at least get THAT right? How many times does it have to be repeated in this thread that there are 127? Or, do we need an authority to come online, like Dave Smith himself to settle the argument once and for all? On second thought, nah, why bother, because you'd probably tell him he's wrong too. (And if you don't know who Dave Smith is, look him up).

Now someone might say, "127 or 128, what's 1 level of velocity between friends?" Well, it makes all the difference in the world. If you (and others) can't get THAT right then what's the point of having this discussion at all?

ozy wrote:
b) forget about 128 sample layers: physical modeling will get there LONG BEFORE technology allows for 128 sample layers.

Will get there?

http://www.pianoteq.com/

I see where both ski and Kevin are coming from (and btw zero is a level so ya I count 128 too. Let's not be so quick to bite off that last - uh - bit - of that last - err - byte)

rrricky rrrecordo wrote:I see where both ski and Kevin are coming from (and btw zero is a level so ya I count 128 too. Let's not be so quick to bite off that last - uh - bit - of that last - err - byte)

I'm sure you're just saying to take the p!ss because you can't really be serious, can you?

I mean, you're not really being, like... you know... serious, right?

OK, all kidding aside. Seriously, you didn't really mean that... you know, the thing about a velocity of zero being a level. Or did you?



Wait...

Wait...

Oh I get it. Man, you really got me with that one! That's just... yeah, you got me alright. You got me good! See, I thought you were being se...ri.......ous....
















Zero is NOT a level in MIDI velocity. Zero is a reserved value for those implementations where a note on message is used as a note off message.

What? Me serious?

http://www.planetoftunes.com/sequence/statdata.html

That link provides no information about velocities of zero.

[ insert game show buzzer sound here ] Sorry, please try again.

Ok

From this page...

http://web.physik.rwth-aachen.de/~harm/ ... ibnin.html

...this feller claims that "Because a data byte starts with a 0 in the binary number, 01101100, there are 128 possible values."

Or levels?

I just wrote a song I call "It's a Bit Quiet". It only has two notes, a C ## and an E bb (you should see the key signature... and the time signature - fuggeddaboudit, it's off the hook!) The two notes go way up to a value (level) of 1, but all those frikkin rests are represented by a value (level) of... well, why don't you tell us all, Peter?

Dingdingdingdingdingdingding... Tell 'im what he's won, Johhny!

Dingdingdingdingdingdingding... Tell 'im what he's won, Johhny!

********************************
"He's won this beeeeeyooooooteeeeful MIDI... WORKSTATION!!!
Yes, that's right, he's won the grand-daddy of all workstations, the Korg KRONOS!
Yes, it's the KRONOS, a 16 part multi-timbral workstation featuring nine incredible sound engines,
an E-Z-KLEEN velocity-sensitive 88 note weighted keyboard,
and enough parameters to keep a musician so busy that they'll forget that there's an outside world!
Yes, it's the KRONOS, by Korg!"
********************************

Wow, what a prize, eh?

But then SOMEONE (ahem) just had to go look a gift horse in the mouth, and what they discovered -- much to their abject HORROR -- was that you can't play a note really really really really really really softly and achieve a velocity value of zero.

Oh, the humanity! Ripoff! Price gouging! It's Korg up to their old tricks again! They're always trying to get one over on us. There oughta be a law! It's all Korg's fault!!

Or is it?

Let's find out! Here's a quote from the MIDI Bible, Chatper 0, Verse 127:

And it came to pass that all MIDI devices were to respond to Note-On commands with a velocity of zero as though they were Note-Off commands.

And now it's time to put some thought into this...

Think about it: let's say that Note-On messages were actually capable of generating a velocity of zero if you played really soft. That note would never sound because, as you just read above, ALL MIDI DEVICES respond to Note-On commands with a velocity of zero as though it was a Note-Off command.

Ta. Da.

Next!?!!?

Peter, your way of conducting a discussion is untolerable!

You keep repeating trivial facts,

as if being factually wrong would necessarily change one's mind about perfectly legitimate personal opinions!

That's against forum etiquette.

Never, ever, let reality mess with good theories.