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Stage piano key action and static touchweights


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To contribute some completely objective information on stage piano key action, I've measured static touchweights for several current models. Most of the feel of a piano keyboard is subjective, in the total experience of the dynamic sound response to key force and movement. But there is a completely objective component, easy to measure, namely the amount of force necessary to push the key down to the point of sounding, and the amount of force the key pushes upward from from its lowest position. Both contribute to the lightness/heaviness of the feel, and ease of playing.

 

Here's the method (Reference here): I took 30 nickels and a few pennies to a keyboard superstore (Just Music in Berlin) and measured the downweight for the lowest key, middle C, and the highest key, and the upweight for middle C. I also measured the drop, the distance the key travels from top to bottom.

 

Downweight is measured by stacking nickels (sometimes plus a penny) flush with the forward edge of the key until you just reach the mass necessary for the key to travel far enough down to sound (volume all the way up through headphones).

 

Upweight is measured by holding the key all the way down with a stack of nickels, and removing nickles (sometimes plus a penny) until the key springs all the way back to the top and stays there.

 

Then you multiply the number of coins of each type by their mass in grams to get the total grams in both weights.

 

 

 

A couple disclaimers: there is some variation in how people define the downweights -- for example, the weight necessary for the key to move some distance, ignoring sound triggering. I've defined it as the distance necessary to just trigger the sound, as I think that's the most objective way to do it, and the easiest to copy.

 

Also -- I'll be looking around other keyboard stores while I'm in town this week -- are there any boards I've left out that you'd like to see measured (I'll edit the post as I find them)? I'll be looking for Kurzweils at some point this week, none in this particular store. Any other measurements you think would be useful?

 

I've sorted these by descending downweight mass. Some observations: there is a lot of variation from key to key within each board, and between boards with the same action (for example the Yamaha CP73, the keys were pretty variable across the board). Also, the only fully acoustic action in this list is the Yamaha NU1X, a hybrid board with a real upright action, but no strings. Interestingly it had the lightest action, and also the most sluggish (lowest upweight because of the friction of the moving parts).

 

I think it's great to have this info -- finally some real numbers for comparison.

 

http://www.stewartschultz.com/Music/Selection_999(535).png

 

 

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Interesting info. I"m not sure about what sounds like an assumed correlation between low upweight and perceived sluggishness. One of my biggest knocks on some actions is that they push up too hard against your fingers, but that doesn't necessarily mean they feel "quick." Or to put it differently, my actual grand piano doesn't seem to push up against my fingers much at all, but it feels quick!

 

Related, an interesting additional measurement (but with no easy way to measure that I can think of off-hand) would be the time between releasing a fully depressed key and when it comes to rest at the top of the travel with no further bounce.

 

Others that would be interesting to chart, if you come across them:

Korg Kronos 73 or 88 (it's RH3 like the SV1/Grandstage, but definitely feels different from the SV1 at least)

Yamaha MODX8

Yamaha DGX660 (DGX660 and MODX8 both have GHS like the P125, but they felt pretty different from each other when I tried them next to each other)

Kurzweil PC4 or SP6

Kurzweil Forte or Forte 7

Nord Piano 4

Nord Stage 3 88

Nord Stage 3 76 or Electro 6 HP

Roland FA-08 or Juno DS88 (Ivory Feel G)

Roland FP-10, FP-30, or FP-60 (PHA4)

Roland RD-2000, Fantom 8, or FP-90 (PHA50)

Casio PX5S or PX560 or PX360

 

Maybe this is the best place for a shameless plug! Our now not-so-new new video at https://youtu.be/3ZRC3b4p4EI is a 40 minute adaptation of T. S. Eliot's "Prufrock" - check it out! And hopefully I'll have something new here this year. ;-)

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I notice the Casio PX S has a relatively higher upweight than others.

And all the weights are far more than any decent acoustic piano reveals.

 Find 660 of my jazz piano arrangements of standards for educational purposes and tutorials at www.Patreon.com/HarryLikas Harry was the Technical Editor of Mark Levine's "The Jazz Theory Book" and helped develop "The Jazz Piano Book."

 

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Many thanks for the work! When I'm reading discussions/ reviews of keyboards, I'm often left confused about subjective terms to describe action such as light, heavy, fast, slow, etc. As a result, it's great that you're making a systematic effort to alleviate the subjectivity by quantifying the parameters.

 

I would encourage you to continue your work and to incorporate as many other keyboards as possible into the data set, perhaps starting with the ones suggested by AnotherScott. It would perhaps also be useful to incorporate more acoustic pianos into the data set as well as semi-weighted keyboards.

 

Gigs: Nord 5D 73, Kurz PC4-7 & SP4-7, Hammond SK1, Yamaha MX88 & P121, Numa Compact 2x, Casio CGP700, QSC K12, Yamaha DBR10, JBL515xt(2). Alto TS310(2)

 

 

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Thanks for the work and the comparisons!

 

I have to wonder which stage pianos and/or controllers out there would supply similar action to the most realistic NU1X in a compact format. Yamaha, with all its resources, seems to send different actions out there simply to see what buyers will settle for. If they made it a priority to design a compact DP action that replicates the specs of their own NU1X, their mass-manufacturing could make it feasible to include realistic piano action in every 88-weighted DP, at a spectrum of price points.

 

The chart is telling me to avoid them all, at this point.

 

 

____________________________________
Rod

Here for the gear.

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Yamaha, with all its resources, seems to send different actions out there simply to see what buyers will settle for.

 

Agreed. The difference between the CP 88 and the CP 73 is amazingly large.

 

In Yamaha's defense, the CP88 is marketed for players wanting a more realistic piano feel, while the CP73 is marketed as having a faster and lighter, more electric-piano like feel at a significantly lighter weight.

 

What stood out to me from the data is how the graded-weight action of the Kawai MP11SE was heavier in the middle of the keyboard rather than the lowest end. I wonder if that's an anomaly in the particular keybed tested, or is reproducible across instruments? Very strange. I also wonder if the grand piano/seesaw-like design of the Kawai wooden key actions might feel different to the hands compared to the end-pivot designs of most other keybeds. Different inertia despite a similar touch weight, perhaps?

 

Overall, I think "action geeks" will find this information fascinating and want more data (count me here), while others will just trust their hands and shrug at the numbers; both appropriate for their own adherents.

 

I think the pivot length and key weight numbers are valuable to have, and like AnotherScott would be curious to see the speed of the action measured in some way as well. It'd be a resource for the community to have a spreadsheet available somewhere as a reference.

 

edit: the CP73 is also marketed as having a balanced (i.e. even) action; interesting to see the variation across the keybed. Quality control issue? Perhaps just takes a bit of time for a new action to "bed in"?

 

It's also interesting to note the difference between the Nord Grand and the Kawai MP7SE. Perhaps lightening and evening the touch weight across the keybed is the primary modification requested by Nord to the Kawai action?

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Interesting info. I"m not sure about what sounds like an assumed correlation between low upweight and perceived sluggishness. One of my biggest knocks on some actions is that they push up too hard against your fingers, but that doesn't necessarily mean they feel "quick." Or to put it differently, my actual grand piano doesn't seem to push up against my fingers much at all, but it feels quick!

 

Well since f = ma or a = f/m, the return speed depends on both the upweight and the mass of the key. Maybe that's why the high end Yamahas (esp the P-515) have such high upweights, to balance the mass of the solid wood keys. I guess you could consider that the main advantage of a hollow plastic key: faster return for a given upweight.

 

Related, an interesting additional measurement (but with no easy way to measure that I can think of off-hand) would be the time between releasing a fully depressed key and when it comes to rest at the top of the travel with no further bounce.

 

Actually that would be the easiest thing to measure of all: just take a video of a released key, playback slow with a stopwatch. I'll absolutely do this today, this is gonna be great. Thanks for the suggestion :-)

 

Others that would be interesting to chart, if you come across them:

Korg Kronos 73 or 88 (it's RH3 like the SV1/Grandstage, but definitely feels different from the SV1 at least)

Yamaha MODX8

Yamaha DGX660 (DGX660 and MODX8 both have GHS like the P125, but they felt pretty different from each other when I tried them next to each other)

Kurzweil PC4 or SP6

Kurzweil Forte or Forte 7

Nord Piano 4

Nord Stage 3 88

Nord Stage 3 76 or Electro 6 HP

Roland FA-08 or Juno DS88 (Ivory Feel G)

Roland FP-10, FP-30, or FP-60 (PHA4)

Roland RD-2000, Fantom 8, or FP-90 (PHA50)

Casio PX5S or PX560 or PX360

 

The store has most if not all of these (except the Kurzes) -- will take another look today. Really want to find those Kurzweils to measure.

 

On that note: any forum members who want to get out a roll of nickels and try this with their own boards (on the list or not), go for it, we can compile a very useful database.

 

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Many thanks for the work! When I'm reading discussions/ reviews of keyboards, I'm often left confused about subjective terms to describe action such as light, heavy, fast, slow, etc. As a result, it's great that you're making a systematic effort to alleviate the subjectivity by quantifying the parameters.

 

Yes, exactly why I did this! Wouldn't it be great for us if the manufacturers reported these measures as part of the spec list for every board they advertise?

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I have to wonder which stage pianos and/or controllers out there would supply similar action to the most realistic NU1X in a compact format. Yamaha, with all its resources, seems to send different actions out there simply to see what buyers will settle for. If they made it a priority to design a compact DP action that replicates the specs of their own NU1X, their mass-manufacturing could make it feasible to include realistic piano action in every 88-weighted DP, at a spectrum of price points.

 

The chart is telling me to avoid them all, at this point.

 

 

It's interesting isn't it? Acoustic uprights tend to have lighter action because the strings and soundboard are vertical, so the hammers don't have to work against gravity. This is why people want the heavier grand action, to keep their fingers strong enough to play a Steinway or Bosey if needed or available. Raises the question: do people who practice on acoustic uprights have weaker hands than those practicing on grands?

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In Yamaha's defense, the CP88 is marketed for players wanting a more realistic piano feel, while the CP73 is marketed as having a faster and lighter, more electric-piano like feel at a significantly lighter weight.

 

Isn't it interesting that Korg went the opposite route, namely kept the heavy weighted action for its SV1-73, whose weights are almost identical to the Yamaha CP4!

 

I think the pivot length and key weight numbers are valuable to have, and like AnotherScott would be curious to see the speed of the action measured in some way as well. It'd be a resource for the community to have a spreadsheet available somewhere as a reference.

 

Unless there's an engineer who disagrees, I'd say the best estimate of key weight will be the product of the upweight and the return time (since m = f/a). I think we'll find that product is highest for the boards with wooden keys, and that it's a good predictor of the total weight of the keyboard.

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Related, an interesting additional measurement (but with no easy way to measure that I can think of off-hand) would be the time between releasing a fully depressed key and when it comes to rest at the top of the travel with no further bounce.

 

Actually that would be the easiest thing to measure of all: just take a video of a released key, playback slow with a stopwatch. I'll absolutely do this today, this is gonna be great. Thanks for the suggestion :-)

Cool! ANd maybe you could also take note of the amount of bounce as well. I'm thinking, initial time to return to top (even if there's subsequent bounce) and then *also* time to final rest after any bounce (so the two times may or may not be identical, i.e. if there's no perceptible bounce vs. some bounce).

Maybe this is the best place for a shameless plug! Our now not-so-new new video at https://youtu.be/3ZRC3b4p4EI is a 40 minute adaptation of T. S. Eliot's "Prufrock" - check it out! And hopefully I'll have something new here this year. ;-)

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I have to wonder which stage pianos and/or controllers out there would supply similar action to the most realistic NU1X in a compact format. Yamaha, with all its resources, seems to send different actions out there simply to see what buyers will settle for. If they made it a priority to design a compact DP action that replicates the specs of their own NU1X, their mass-manufacturing could make it feasible to include realistic piano action in every 88-weighted DP, at a spectrum of price points.

 

The chart is telling me to avoid them all, at this point.

 

 

It's interesting isn't it? Acoustic uprights tend to have lighter action because the strings and soundboard are vertical, so the hammers don't have to work against gravity. This is why people want the heavier grand action, to keep their fingers strong enough to play a Steinway or Bosey if needed or available. Raises the question: do people who practice on acoustic uprights have weaker hands than those practicing on grands?

 

Like many people here, I play grand pianos for a living. I have yet to find a DP/controller action that isn"t too heavy or too light, and I have demoed them all. So Yamaha markets their CP73 as 'faster, lighter.' Well of course they do! Marketing 101.

 

To the notion that people want heavier grand action to keep their fingers strong enough - maybe it does that, but at the expense of joint & muscle pain, split skin, while I could play a real grand all day. And although it has nothing to do with strength anyway, the analogy of lifting weights is better expressed in lower pounds + more reps = mo betta

____________________________________
Rod

Here for the gear.

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In Yamaha's defense, the CP88 is marketed for players wanting a more realistic piano feel, while the CP73 is marketed as having a faster and lighter, more electric-piano like feel at a significantly lighter weight.

 

Isn't it interesting that Korg went the opposite route, namely kept the heavy weighted action for its SV1-73, whose weights are almost identical to the Yamaha CP4!

 

I think the pivot length and key weight numbers are valuable to have, and like AnotherScott would be curious to see the speed of the action measured in some way as well. It'd be a resource for the community to have a spreadsheet available somewhere as a reference.

 

Unless there's an engineer who disagrees, I'd say the best estimate of key weight will be the product of the upweight and the return time (since m = f/a). I think we'll find that product is highest for the boards with wooden keys, and that it's a good predictor of the total weight of the keyboard.

 

I was referring to the up and down key touch weight, not the actual weight of the keys, but the mass of the key would affect its momentum or "inertial feel."

 

There's much more to the feel of action than just the physics and touch weights; those equations assume a frictionless system. The design of the key's pivot and the nature of the resistance/friction built into the mechanism are also big factors in how the board feels under the fingers. An acoustic grand or wooden/teeter-totter action like in Kawai's wooden actions might have a somewhat high initial touch weight to get the key moving, while having relatively high inertia and very low friction/resistance once it's started. A short folded action in a mid-priced DP might have the same touch weight to start moving, but have constant friction and resistance all the way down due to the design of the weighting mechanism and pivot and therefore feel very different, more sluggish and less authentic.

 

From a design standpoint, it seems clear that the design of Kawai's wooden key actions makes a lot of sense if you can accept the weight penalty. The long pivot point, teeter-totter style pivot design, and actual solid wood keys seems like it takes a much more straightforward approach to emulating a grand piano action. I am still waiting to see when Kawai can put the GF2 into a slab piano, maybe an MP12 or VPC2. I also wonder if the VPC, when it's upgraded, will get the Grand Feel Compact action rather than the GF2. I hope not, as if they're making their most piano-like controller, it should have their best, most realistic action.

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Since I happen to have the two instruments handy, I might as well add what I can. It's a tricky test for a lot of reasons, potential lack of standardization being the main one. Having the stack of coins fractionally further back or leaning slightly out or in made enough of a difference that I tried to be quite rigorous regarding a straight stack, even with the outside edge of the key and not creating friction with the adjacent key. Upweight was also tricky because there's a huge difference between slowly removing coins until it's back in a fully upright position, and fully depressing the key after each removal to see if it returns to a fully upright position from there. I chose the latter. I also measured the stack of coins each time rather than assuming an average weight, since mine weren't uniformly pristine specimens.

 

I did not measure key travel as I don't seem to have anything handy that I'd claim was precise enough for the job.

 

Kurzweil Forte 8 (Fatar TP/40L)

 

Low key (down / up) - 105 / 64

Mid C (down / up) - 90 / 44

High key (down / up) - 86 / 45

 

I'm pretty sure the high measures for the low key are some byproduct of the way the edge of the keybed differs from the more uniform situation of having adjacent keys on each side. Perhaps there's something brushing the key lightly on the exposed side? Unclear. The next lowest natural key seemed more in line with Mid C and the highest note, which makes sense since this isn't supposed to be a graded action.

 

Shigeru Kawai SK-7 Grand

 

Low key (down / up) - 91 / 42

Mid C (down / up) - 90 / 44

High key (down / up) - 86 / 45

 

I thought it was worth adding at least one true acoustic grand action in the mix, and I was only mildly surprised to see that it matches up with the "light" Fatar hammer action. It's one of the many things I love about this particular piano. The very mild grading is potentially interesting, and variation in upweights is small enough that it could have more to do with my technique than any actual variability.

Acoustic: Shigeru Kawai SK-7 ~ Breedlove C2/R

MIDI: Kurzweil Forte ~ Sequential Prophet X ~ Yamaha CP88 ~ Expressive E Osmose

Electric: Schecter Solo Custom Exotic ~ Chapman MLB1 Signature Bass

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Having the stack of coins fractionally further back or leaning slightly out or in made enough of a difference that I tried to be quite rigorous regarding a straight stack

 

If that's the case, and if you use the edge of the key as a guide, then the answer's very sensitive to the distance between the pivot point and the end of the key. Which makes sense I guess if the edge of the key is what players use as a reference to decide where to touch the key. Still, I'm not sure that's the most useful measurement. Might be more useful to have key dimensions and torque as separate measurements.

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"Static Touchweight (TW)

Static touchweight is a term that encompasses three concepts: ⢠Downweight: minimum force required to depress the key ⢠Upweight: maximum force the key will overcome as it returns to the rest position ⢠Balance weight: the average of downweight and upweight forces These weights or forces (discussed below) determine the perception of action as heavy or light during soft playing. Together with action regulation, touchweight is of great importance for control in soft dynamics.

Static and Dynamic Touchweight Static touchweight, defined above, describes static forces required to depress, release, and balance the key. The finger, however, depresses the key with a wide range of forces (technically, kinetic energy), attempting to accelerate it at different rates. The resistance the finger experiences during rapid accelerations in loud playing is caused by inertia, and is referred to by some technicians as dynamic touchweight. This is discussed under 'Inertia' below.

Downweight (DW) and Upweight (UW)

Downweight is the weight on the front of the key needed to make the key sink slowly from a point approximately 4 mm below its rest position. The reason for measuring at the 4 mm dip is to overcome the friction and leverage at the top of key travel, where they are highest (see 'Friction Changes During Key Travel' and 'Leverage Changes During Key Travel' below). The ideal downweight ranges from about 50 grams in the bass to 46â47 grams in the treble, with 48 grams being a good target for the middle section. A downweight over 55 g (57â58 g in the bass and 54 g in the treble) will be perceived as heavy, especially when combined with high front weight (inertia). A downweight of 45 g or less will feel lightâit is acceptable only if the up

weight is at least 20 g and the front weight (explained below) is under the recommended ceiling. Variations from note to note should be within ±2 g. Upweight is the maximum weight on the front of the key that the key will lift on its own. As stated above, upweight is related to downweight (and balance weight) more or less linearlyâincreasing one increases the other by the same amount. On a piano with fairly new, well-lubricated action parts and a downweight of 48 g, the upweight should be 23â24 g. A high upweight feels springy and responsive, whereas a low upweight makes the action feel sluggish and slows repetition. As with downweight, variations from note to note should not exceed ±2 g.

How to Measure Downweight: For both white and black keys, place weights on the front of the key (Figure 460) so that the center of the weights is 13 mm in from the front edge. This is the standard measurement position (SMP). If the action is in the piano, keep the damper pedal depressed. Push the key down approximately 4 mm. The least amount of weight that makes the key slowly drop from that point is the downweight. Upweight: Hold the damper pedal depressed and depress the key to the point of increased resistance (7â8 mm). Starting with about 20 grams, place the weights on the standard measurement position and release the key. Adjust the weights until the key barely returns to the 4 mm point. Alternatively, measure downweight by slowly depressing the key, and upweight by slowly releasing it with a tension gauge, as shown in Figure 461. Enter and plot the downweight and upweight values on the Touchweight Worksheet (page 277). For now, ignore the balance-weight areaâyou will learn how to calculate balance weight below.

Friction (F)

The difference between downweight and upweight is caused by friction in the keyboard and action parts. Given the same downweight, the higher the upweight, the lower

Touchweight "

 

http://www.pianosinsideout.com/action.pdf

 Find 660 of my jazz piano arrangements of standards for educational purposes and tutorials at www.Patreon.com/HarryLikas Harry was the Technical Editor of Mark Levine's "The Jazz Theory Book" and helped develop "The Jazz Piano Book."

 

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No wonder playing a digital piano is so tiring, you have to press a lot more weight.

 

A grand piano, with its repetition lever and no reliance on springs to release the hammer; pianists can play faster on a grand piano.

 

 Find 660 of my jazz piano arrangements of standards for educational purposes and tutorials at www.Patreon.com/HarryLikas Harry was the Technical Editor of Mark Levine's "The Jazz Theory Book" and helped develop "The Jazz Piano Book."

 

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No wonder playing a digital piano is so tiring, you have to press a lot more weight.

 

A grand piano, with its repetition lever and no reliance on springs to release the hammer; pianists can play faster on a grand piano.

Yep. Try playing Billy Joel"s Angry Young Man on just about any digital keyboard.

 

I would like to apologize to anyone I have not yet offended. Please be patient and I will get to you shortly.
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The experienced difference between overcoming inertial forces and playing something with fixed resistance exerted by springs is so dramatic that I'm always amazed there's any kind of market for the latter outside extremely lightweight synth actions. I've always found the TP/8Piano action to be an insulting and exhausting surface to play on, and yet there are those who don't seem to mind. Kurzweil used them for their 76-key actions before the Forte, if memory serves, and Sequential went with it for the Prophet XL, which I wouldn't trade my Prophet X for under any circumstances.

 

Part of the reason I took the time to run this test on a couple of instruments here is that I'm looking for a new master controller for a second studio space and wanted an objective measure of what I like as a reference point. So please, keep those additional measures for other options coming! I'm currently torn between leaning all the way in on keyboard action with something like a VPC-1, and trying to balance controller features and synthesis potential with action.

Acoustic: Shigeru Kawai SK-7 ~ Breedlove C2/R

MIDI: Kurzweil Forte ~ Sequential Prophet X ~ Yamaha CP88 ~ Expressive E Osmose

Electric: Schecter Solo Custom Exotic ~ Chapman MLB1 Signature Bass

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Thank you Lady Gaia -- I added your numbers to the chart.

 

Today I measured all the Steinways at the Steinway store in Berlin, and the rest of the weighted hammer action boards at JustMusic.

 

I also included an additional number, the "distance to hinge" that is an estimate of the horizontal distance to the apparent hinge point indicated by the geometry of the key travel distance. I measured the travel distance at the end of the key, and 14cm in from the end. The difference divided by 14 is the slope of the key when it is depressed all the way down. The travel distance at the end of the key divided by the slope is equal to the "distance to hinge" number.

 

I also videotaped the key return for all these boards, but I'm not sure this is going to be useful -- the return speed is so fast that all you can do is count the frames as it springs to the top, and for the first 10 boards I looked at, the number of frames was 3, maybe plus-or-minus a half a frame. So it appears any differences in return time are too small to be measured by video frame counting.

 

Anyway, here's the full chart so far (including Lady Gaia's numbers). I've sorted descending by the average of the three downweights. This chart is now also in the updated OP -- but some explanations are here as the OP text can no longer be edited.

 

http://www.stewartschultz.com/Music/Selection_999(537).png

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No wonder playing a digital piano is so tiring, you have to press a lot more weight.

 

A grand piano, with its repetition lever and no reliance on springs to release the hammer; pianists can play faster on a grand piano.

Yep. Try playing Billy Joel"s Angry Young Man on just about any digital keyboard.

 

Springs aren't at all necessary in a DP action -- my Roland RD 700 has no springs at all, just plastic keys and metal weights on a hinge in a plastic chassis. Nothing but gravity brings the key back to resting position.

 

I have no idea what DPs use springs -- if anybody else knows, I'd sure like to hear which ones use them, and why.

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I was referring to the up and down key touch weight, not the actual weight of the keys, but the mass of the key would affect its momentum or "inertial feel."

 

There's much more to the feel of action than just the physics and touch weights; those equations assume a frictionless system. The design of the key's pivot and the nature of the resistance/friction built into the mechanism are also big factors in how the board feels under the fingers. An acoustic grand or wooden/teeter-totter action like in Kawai's wooden actions might have a somewhat high initial touch weight to get the key moving, while having relatively high inertia and very low friction/resistance once it's started. A short folded action in a mid-priced DP might have the same touch weight to start moving, but have constant friction and resistance all the way down due to the design of the weighting mechanism and pivot and therefore feel very different, more sluggish and less authentic.

 

From a design standpoint, it seems clear that the design of Kawai's wooden key actions makes a lot of sense if you can accept the weight penalty. The long pivot point, teeter-totter style pivot design, and actual solid wood keys seems like it takes a much more straightforward approach to emulating a grand piano action. I am still waiting to see when Kawai can put the GF2 into a slab piano, maybe an MP12 or VPC2. I also wonder if the VPC, when it's upgraded, will get the Grand Feel Compact action rather than the GF2. I hope not, as if they're making their most piano-like controller, it should have their best, most realistic action.

 

The measured weights are a result of both gravity and the friction of the system, so should be informative whether the mechanism is a teeter-totter or folded design.

 

I wonder if inertia really is a problem -- if it was, then why add lead weights to keys, as Steinway does? The big D-274 that I looked at had three lead weights in most of the keys, tapering to two in the middle and one at the top. You can expose them by pressing a neighboring key. Amazing -- adding weights to the near end of the pivot makes them require less force to move the hammer to a threshold speed, but certainly increases the inertia. If there is a weight penalty Steinway doesn't seem to believe in it.

 

Absence of the need to strike a heavy string with a minimum force is a big advantage, giving way more freedom in designing the key mechanism -- there's no need to weight your keys, you can make the action as light as you want, you don't have the same space and geometry requirements, etc. You'd think it would be possible to use that freedom to create a design that would satisfy everybody :-)

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The experienced difference between overcoming inertial forces and playing something with fixed resistance exerted by springs is so dramatic that I'm always amazed there's any kind of market for the latter outside extremely lightweight synth actions. I've always found the TP/8Piano action to be an insulting and exhausting surface to play on, and yet there are those who don't seem to mind. Kurzweil used them for their 76-key actions before the Forte, if memory serves, and Sequential went with it for the Prophet XL, which I wouldn't trade my Prophet X for under any circumstances.

 

Part of the reason I took the time to run this test on a couple of instruments here is that I'm looking for a new master controller for a second studio space and wanted an objective measure of what I like as a reference point. So please, keep those additional measures for other options coming! I'm currently torn between leaning all the way in on keyboard action with something like a VPC-1, and trying to balance controller features and synthesis potential with action.

 

Damn! They had a VPC-1 on display at JustMusic, with some sound module connected, but I didn't bother to check it out! Guess I'll have to go back :-) They also have Studiologic controllers there (Stage and Grand).

 

I'm intrigued by people mentioning springs in this thread, does the TP/8 have springs?? I never considered the possibility that DPs would have them until now -- I've taken apart my boards many times (Privia and Roland RD-700) for repairs, and there is nary a spring in sight.

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I'm intrigued by people mentioning springs in this thread, does the TP/8 have springs??

 

I can't say categorically whether all TP/8 variants feature springs, but some of them most certainly do and my guess is that this is uniformly the case for all TP/8 designs:

 

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I'm intrigued by people mentioning springs in this thread, does the TP/8 have springs??

 

I can't say categorically whether all TP/8 variants feature springs, but some of them most certainly do and my guess is that this is uniformly the case for all TP/8 designs:

 

Aha, yes, that's a semi-weighted board, not hammer action, so makes sense, springs really provide the only "weight". I don't think they use springs for their hammer action boards. Some apparently do though, for example the Medeli LK action (used in Kurzweils) was a hammer action with springs, as shown here (1:05 mark):

 

 

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Aha, yes, that's a semi-weighted board, not hammer action, so makes sense, springs really provide the only "weight". I don't think they use springs for their hammer action boards. Some apparently do though, for example the Medeli LK action (used in Kurzweils) was a hammer action with springs, as shown here (1:05 mark):

 

I can't tell much from that video. But semi-weighted boards do have weights, separately from springs. Unweighted boards have springs without weights (or may not have springs at all, some use just the tension of a plastic hinge). As for hammer action boards, I know Korg's RH3 has springs... they are leaf springs, though, i.e. not the coiled kind illustrated above. Do most or even all hammer actions have such springs as well? I don't know.

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