Piano World Home Page Forums Our Most Popular Forums Digital Pianos - Electronic Pianos - Synths & Keyboards Dual vs Triple sensor technology - PianoManChuck

No moving parts, so no wear and tear. Don't have to clean them.
And more precise.

The Yamaha hybrids (AG and NU1) use optical sensors.

Let me rewind the clock to the time I was 4 years old...

ZZzzzz.... And this was clearly edited down to 10 minutes! Presumably the part where his fetal ears perceived the first tinkling of piano while suspended in utero ended up on the cutting room floor.

He says very few DP manufacturers have triple sensor technology - yeah, only Roland, Yamaha, Kawai, Casio, etc., etc. have the nuclear secrets hard drive.


Exactly.

I'm not sure why he was saying the timing between various and sundry sensor events would be useful, particularly on the way to key down. They could be, but I kind of doubt if any DP manufacturer actually does this.


It's actually the opposite. You want the middle and bottom sensors to be quite close to each other and as near the bottom as possible so that any variation in the velocity is averaged over a smaller interval of travel and final velocity is best measured. Timing available on even a fairly asthmatic processor is usually more than sufficient to resolve and measure events from closely spaced sensors.

You want the top sensor as near the top as possible, or at least sufficiently far away from the middle sensor, so that trills don't damp.

So why not put it in the other DP's too ??
I would see this as a plus for the manufacturer.

Once again ... it's all about cost.
Rubber buttons are cheap to build and cheap to assemble.
Consider that the same type of rubber buttons are used in TV remote controls ... even in those that sell for $10.
They're very inexpensive, and they work well.

Yeah, your probably right.

I'm just not really seeing the upside, really - it maybe cooler tech and all - which sometimes is an end in it's own right - but would it be a comprehensively better solution for the end user?

There's nearly always something that can be gummed up or affected by calibration or dust when optical stuff is used. There's also going to be repetitive vibration.

If it was cost neutral - which I doubt - then is servicability and MTBF definitely superior?

Here's a followup video comparing triple sensor between Kawai VPC1 and Casio PX5S:

I tried a test similar to what PianoManChuck does, with the repeated and very small lift of the key, on my AP-245 - which should have the same action as the PX5S (common action on the current PX and AP Casio series), with triple sensors.

At first I couldn't get it to miss notes, but if I consciously tried to defeat it by only lifting the key by the smallest amount possible, I got missed notes - but I had to actively try and do so, whether I'd find that in normal playing I'm unsure - doubtful, even.

Then I tried the same test on my real piano (an upright) - this was the big surprise to me. It was almost exactly the same as my AP-245 - in fact I'd say it was slightly easier / took less effort to defeat my real piano.

Accepted I've only ever played grand pianos on truly very occasional instances, is there much difference in that sort of response between an upright piano, and a grand?

The strange thing is, the VPC1 is double the price of the PX-5S in the U.S., but Thomann (Germany) offers the VPC1 with the Ivory II American Concert D, at approximately the same price as the PX-5S, when considering what Ivory II ACD costs.

I've often thought I would have loved Kawai VPC1 instead of Casio PX-5S, but then again the piano voices of the PX-5S are quite good, it has great organ sounds, guitars, harpsichords and so on. It does have it's advantages to be free from hooking a laptop (or a smart computer) to your digital piano.

It's good to know that the tri-sensor technology of Kawai's VPC1 is superior to that of Casio's flagship, assuming this test is scientific. Regardless, the VPC1 seems a pretty advanced MIDI controller. That is of great importance, at least to European consumers.

In the second video PianoManChuck spends ages talking about how the VPC1 plays legato better. I think this is because it transmits note-off velocity, which most instruments don't, and has nothing to do with triple sensors.

My own experimentation shows that the note-off velocity is calculated by the time between the release of sensor 3 and sensor 1, so sensor 2 is not needed for this feature. If you wanted a realistic calculation of note-off velocity, you'd need a 4th sensor close to sensor 1, to sense the point at which the dampers first touch the strings. Currently, if you release the key halfway, pause, then release fast, it registers as a slow note-off velocity, whereas it should be fast since it's only the velocity that the dampers hit the strings that should matter.

I spent ten minutes watching that video and came away with the thought that the video could have been done in several minutes.

I was curious to learn just how many sensors my N3 or CP5 has.

No where in the specs of either keyboard is that specific information posted. Should I assume that any keyboard worth its salt has three sensors?.

I should add that when I play these keyboards I never feel that I am limited in any way.

N3: AFAIK, yes, (or at least, it emulates double-escapement, which is really what we're trying to achieve with the 3rd sensor), but there have been reports that it does NOT allow "playing off the jack".

CP5: I don't think it does.

Greg.
p.s I haven't watched any of the videos yet.

Would the difference of arm angles not favour a more controlled response for the Kawai?

The N3 has a 'continuous' sensor at the hammer, let's call that two, and another sensor under the key. I am not sure if the timing information from the key sensor counts in the sense of a third sensor in this discussion.

Certainly the N3 key action allows you to repeat a note without fully lifting the key, more so than on an NU1 which only has the hammer optical sensor. But then you would expect that anyway since the N3 is a grand (style) action and the NU1 an upright (style) action.