Piano World Home Page Forums Our Most Popular Forums Digital Pianos - Electronic Pianos - Synths & Keyboards 128 note polyphony question

Charles Cohen, yes, you are right : on my comparison I wouldn't find the difference between a 64 notes and a 128 notes rendered polyphony, then I am happy with a 64 notes polyphony digital piano.

But what I dislike is that we can't trust the specifications which are meaningless. We should have a polyphony written in a number of "actual notes".

All specs from all manufacturers are to some extent lies. The specs are still useful if all the competing manufacturer lie the same way, then the number they publish is still meaningful for comparison. It's true of horsepower, mile per gallon, gigabytes, or polyphony.

When was the last time a 1 TB hard drive actually had 1 terabytes? Usually they have 1,000,000,000,000 bytes, when a terabyte is actually 1,099,511,627,776. That means a 1 TB hard drive is typically shorting you by some 10% or almost 100 GB. If every manufacturer does the same thing, then 1 TB from one brand is the same as 1 TB from another even if it is not 1 TB in the real world.

That's just one example. Everything in tech is like that if the company has a marketing department.

The problem is that here we have a x2 factor... (and it would be interesting to see what mean a voice polyphony on a SuperNatural piano).

When I see "note" in a spec I understand "note", not a part of the sound which produce a note.

When we have a 115cv motor, we know it is the power of the engine... what would you think of an engine maker which would sold a so called 300cv engine but only measure the power dissipated by the combustion (and forget to tell you the actual power is 36% of it) ?

You forget to mention the speed of inkjet printers... We had in a time some really fancy figures as if the printers where measured to print blank pages. Now with ISO/IEC 24734, I think the situation is clearer.

Unfortunately they are correct. Terra prefix means factor of 1000^4, so 10^12, according to good old SI.

1,099,511,627,776 bytes = 1 tebibyte = 10 TiB.

If they would talk about 1TiB and provided 1TB they would be pretty eligible for a fine for misleading advertising...

Again, I would be pretty interesting about measuring polyphony for classical four hands pieces.
Not the usual usage I agree, but I bet four hands need more polyphony.

Have you got some pieces of music ?

If I can find the corresponding MIDI files, I can try.

I would suppose that each part of the piece is simpler than the Fantaisie Impromptu I have rendered, then you would not need twice the polyphony. The use of the pedal is important with the polyphony.

I have seen that the CLP150 with 128 notes "Max" differs from other models from the same lineup (CLP120, CLP130) with 64 notes "Max".

They have not the same sound generator. (According to the CLP120 and CLP130 service manual), but the CLP150 has also 480 XG sounds.

When I try with the XG piano sound, I can reach 128 voices... But the "normal" way of playing my digital piano is the default "64 notes" piano.

That is incorrect. Computers are not decimal and nor SI. All units are counted in binary. One thousand bytes (KB) = 1024 bytes in decimal or 2^10 bytes in binary. One MB is 2^20. One GB is 2^30. One TB is 2^40.

BTW, this is a recent practice they switched over to market USB flash storage, the practice of which bleed over to disc storage. I still remember buying hard drives when 120 MB drive had 2^27 bytes and the operating system reported exactly 131072 KB for a 120 MB drive. (Microsoft/IBM DOS reported all disc space in KB.)

The problem is that a kB is near a KiB (2%), then one unit is often used instead of the other. If we get further (MB vs MiB, GB vs GIB, TB vs TiB), it is less true.

Then it seems me normal to use the TB for its actual meaning 1 000 000 000 000 B. k/M/G/T are SI prefixes.

When I read that a network is 100Mbit/s, this means 100 000 000 bit/s exactly. What an OS reports shouldn't make a "case law" about what units means what.

Sorry this is simply wrong. The computer industry has never used SI. 64K has never been 64000. It has always been 65536, going back to the beginning of time.

The fundamental difference is, 1 kg = 1000 g but 1 Kb = 1024 bits. You simply have to accept it as the fundamental of computing.

When I say that 100Mbit/s is 100 000 000 bit/s, I mean that the 100baseT data link has a 125MHz clock (The MHz from the SI unit system).... and since 4 bits are exchanged every 5 clock signals, we have 100 000 000 bit/s.

We have also 9.6kbaud for 9600baud and so on. The 64Kbit/s (ISDN) is also 64 000bit/s (which explains that the voice over ISDN is 8 bits at a 8kHz sampling frequency).

Then in data computing, we have some Mbit which are 10^6 bits and some other which are 1024*1024 bits. This explains the introduction of the Ki Mi Gi Ti prefix which makes things clearer. However, we still read about 4GB memory modules which are in fact 4GiB.

We still have both conventions.

We even have some weird convention : a 1.44MB floppy disk is twice a 720KiB floppy disk. Then the MB from 1.44MB is neither a real MB nor a MiB !!! Here it is 1000*1024 B.

I was actually there in 1998. There reason there is now the different terminology you so clearly pointed out is because of marketing, which is what I was saying. Some vendors that sat on standards bodies, my company included, wanted to be able to change the then accepted standard engineering terminology in order to market something smaller and call it bigger. That's why in 1998, gibibyte was made and GB was aligned to SI. I'm not saying the terminology is wrong even I objected to it back then, and still do. I'm saying consumers were robbed. The motivation was pure marketing, but we made it official for marketing purposes.

It's just like the number of speakers in a DP. It is now convention to count every single speaker cone as speakers even though we never did that before DP came along. How many speakers are here? http://revelspeakers.com/productdetail/~/product/salon2.html. If I was a DP maker, I would say 6 even though it has always been just 1. Just like some sales person on the Internet claiming how there is actually over 100 feet difference between a 5.5 foot and a 6 foot piano because there are 220 strings in a piano. I don't know how people get away with stuff but they will do whatever it takes to claim a higher number to the consumer.

I, too, dislike disreputable specs ...But MOST specs are "junk", so I find it best to ignore them.

And it's easy to do that. All you want from a piano is:
- Good feel. There's no spec for that. Let your fingers be the judge.
- Good sound. There's no spec for that. Let your ears be the judge.
- Some people care about size and weight. Let your eyes and your back be the judges.
- Appearance. Eyes, once again.

It seems to me that there is no need for ANY specs. So whatever specs are touted, I can just ignore them.

I tend to agree. As a musical instrument, specs are pointless. However, I think knowing size and weight is important. It was really helpful to know when I bought my piano that it weighs 704 pounds along with WxHxD, so I could provide an appropriate space with floor that's strong enough to accommodate it. Everything else is unimportant. The marketing literature could say whatever, but the proof is in the playing. From the specs, I would have never guessed that I would prefer the AvantGrand N2 to the N3, for instance.

Some functions can be nice to have (record to WAV, AUX-IN...) and the specs can be useful to spot models which have them. But you are right, to judge a piano, we must consider only its actual use

But I am a little curious and like to know what is under the hood (I have also the service manual). But this doesn't interfere with my judgment.

I have checked a bit further. As far as I see there is only one area where 1k = 1024, and that is semiconductor storage capacity -- for memory integrated circuits and microprocessors (L1/L2 caches). Also see JEDEC 100B.01 standard from 1997.

As hard disks are different technology, they were never compliant to JEDEC...

I wonder if SSD drive sizer are JEDEC or SI compliant... However, JEDEC only specified GB but not TB... and in their newest standard they also moved into the direction of using GiB and TiB, to avoid confusion.

I partly disagree: specs are still somewhat useful.
Especially if you can know certain models of the same manufacturer share the same keyboard and/or sound engine or not

We have a whole timeline of the use of SI vs IEC prefixes : https://en.wikipedia.org/wiki/Timeline_of_binary_prefixes