Piano World Home Page Forums Our Most Popular Forums Digital Pianos - Electronic Pianos - Synths & Keyboards What good is polyphony?

If the digital has 64 poly, then that means it can play 64 notes at once? Is that right?

So I only have 10 fingers. In a pinch, I might be hitting two keys at once on adjacent notes, so maybe, even tho it won't ever happen, 11 notes at once. Factor in a duet, and you've got 20 notes possible.

Is all this polyphony just overkill? What does pedaling have to do with it?

I've been playing digitals since 1989, hard
playing of the most difficult classical
repertoire, and I don't comprehend the fuss
about polyphony. With "low" polyphony you
supposedly hear notes "dropping out," but
I don't know what this means and have
never experienced it as far as I can tell.

My first digital, bought in 1989, had
16 note polyphony. My neighbor now has
it, and I think it sounds better than
the latest digitals with 128 and 192
poly. My next one, bought in 2005, had
32 poly and an optional 64 poly grand
piano, but I could not tell the difference
and so I always used the default 32 note
grand piano because it was most convenient.
My current piano has 60 polyphony, and
it's not much different from the previous
two pianos. I've tried digitals with
128 polyphony, and the sound is maybe
of better quality but not enough to
make me dump my 60 poly piano and buy
them.

So, I see no problem with getting some
hypothetical $400 to 500, unknown-brand,
economy 32-note poly digital, with non-progressive
weighted action and non-half-pedal sustain
pedal. You could save a lot of money on such
an instrument, and it would play similar
to a digital with 128 or more polyphony,
or your acoustic pianos.

That’s a very good question. One answer is that many musicians want the computer to play with them simultaneously on the same instrument. For example, the computer may play from a score in a music editor, like Finale or Sebelius, or from a previously created MIDI file. The MIDI file might contain several simultaneously playing instruments. Expand on this idea and you can quickly run out of simultaneously playing notes. Myself, I’m not a heavy user of such features. I do play simultaneously with the computer often enough, but rarely using more than two instruments on the computer. So, 64 note polyphony is more than I need. These features are especially desirable if you are recording such performances. For example, I can conveniently record the entire performance directly off the one clean audio output of the instrument. No microphones are involved, so the recording can be very high quality using relatively low cost equipment. When you use your instrument like this you are effectively using it as a sequencer.

I don’t know what pedaling has to do with it, but I’d like to know.

If you don't do such work, I agree with Gyro, 32 note poly is more than you need, even if you play duets with another person on the one keyboard, as I often do with my wife.

Keep in mind that a keyboard advertised as "32 note polyphony" only has 16 note polyphony in reality when using a stereo piano sound (which most people prefer).

It is in this scenario that a perceptive listener can hear things dropping out on more advanced/pedal intensive pieces, or in the scenarios Orez Eno mentions above.

For use as a piano, I would think advertised polyphony of 64 notes is preferable, while higher numbers would be good for multitrack sequencer use. Lower numbers are fine for easier piano music and less discriminating listeners.

pedaling and laying more than 1 voice on your digital will eat out more polyphony, and then if you're even trying to play some big chords and fast passages over such, you'd notice some note drops.

64 polyphony is not even overkill but a minimum acceptable standard for today's digitals. that's why all DP makers have already made the minimum 64 polyphony available on all new low end models.

I guess I thought that the sequencer within my piano accepted each MIDI note instruction as mono and then made it into stereo within its own circuitry. Oh my goodness! I guess my instruments have been using twice as many notes as I thought.

In that case 32 note poly would be insufficient even for the simple stuff that I do. Both my instruments have 64 note poly. I haven’t noticed any hiccups or dropped notes, but I didn’t realize how close to the margin I have been operating.

With 64-voice polyphony, it's pretty much gone in stereo after 3 rapid-fire, 2-handed chords. But the good news is that modern keyboards also use smart voice stealing algorithms that try and figure out which voice you're least likely to miss and drop that one first. And reverb processing that will cover up a bit for dropped voices.

Howard

look at most DP brands and you see many of them higher than 64..usually 96 and 128..Yamaha is still at 64..even in the medium price digitals!

I think there is no general answer how many voices you need. If you play just one instrument at a time and do not play like Jordan Rudess you don't need a high polyphony. But...

One preset on a digital instrument can use more than one voice at the same time, meaning you don't hear one instrument using one of the (i.e.) 64 voices, but you hear 2 or 3 or maybe 4 voices at the same to produce one sound. And you can layer sounds yourself like the obvious piano + strings. The more sounds you add the more voices you use. Playing midi sequences, using arpeggiators, styles, etc can also "steal" a lot of voices.

It's amazing how you (or your neighbor) can compare a 1989 keyboard with 32 note polyphony which possibly doesn't even have a stereo sample to a recent keyboard (2007-ish i assume.) and say that the 1989 version sounds better. Granted some older models could be better but are we comparing a top of the line roland to a casio 100? or are we comparing apples to apples?


Hypothetcal is the keyword Gyro. A non-progressivie action (simply each key has the same weight), non half pedal (used to add increased dimension and expressions simulating not a full sustain but a partial sustain), and most likely being made at the economy level qualtiy is no where near comparable to a higher level digital piano such as a high end Yamaha, Roland, Kawai, or even a Casio. Let alone comparing this type of a keyboard to a Yamaha, comparing it to an acoustic (upright or grand) is quite a complete feat). You can't compare a Ferrari to an old Geo Metro can you?

Am I guessing correctly that polyphony is a moot point if one is using piano software programs like Synthogy Ivory or Sampletekk or Pianoteq and other brands and your keyboard then is being used as a "controller" and not using the keyboards internal sounds? I've read that when doing so polyphony is very large and not a concern.

But then you should consider buying a controller with a good action and not a DP -
On the other hand if you plan to play midi files with something like 8 instrument's tracks using the voices of your keyboard, 32 is not much at all. I do believe that stereophonic voices will use 2 generators (1 for each side) - it's the case for my synth.
Now if you want to have midi tracks playing with you playing the piano with some long sustain parts, 64 will show it's limits. 128, I doubt one can reach the point where notes will be dropped, even if they play 32 tracks midi files.

Now I’m curious. If by action you are talking about physical action, wouldn’t a DP have the best action to begin with? My CLP-230 has very good action. Why wouldn’t I want to use it as a controller to some virtual piano software on a computer using MIDI connection between them, as btcomm suggests? Or are you talking about a different kind of action having to do with MIDI? Or are you saying that because of the type of music that people typically play when playing on a controller, as opposed to a piano? Or, are there features of a controller that my piano doesn’t have and that I’ll need in order to use if as a controller?

I’d really like to know this because I am thinking of upgrading the computer that I use with the CLP-230 in order to make it a virtual instrument. Please stop me from spending money for nothing if that is not a good idea.

I guess I'm one of those guys that buys into the polyphony hype then. Let's say you hold the damper pedal while playing a four-note arpeggio played over four octaves while the left hand plays the root note in octaves, that's 18 notes of polyphony. Assuming you're using a stereo sound (the standard nowadays), this becomes 36 notes of polyphony. Now lets say you play the same thing with two combined two sounds (grand piano and vibes for example), both of which use stereo samples. Now you're already using 72 notes of polyphony! And this is just a modest example. Me personally, I have some setups that use 5 or 6 different sounds, a few of which are stereo (double the polyphony).

Now, since we're mainly focusing on digital pianos here, let me give you another example that doesn't have to involve layering sounds. Instead of an arpeggio, think about playing a scale. If you play a scale over 4 octaves, with holding the damper pedal down, and the left hand playing octave root notes (not such a farfetched situation for a non-beginner pianist), that's already 60 notes of polyphony for a stereo piano sound!

Now I'm not saying that everybody will need a ton of polyphony, I'm just saying...it is not that hard to eat up polyphony in a hurry. I noticed dropouts often when I was using a board with 32 notes of polyphony (16 for stereo), so I upgraded. My current board has 64 notes, and I still notice dropouts when I am doing complex layering or using multiple stereo voices :rolleyes: .

Just my $0.02

on my CP33, when I play the church organ sound, if I hold the pedal down and repedately tap the same key, it gets louder with each tap. It's very different from the sound it makes when I hit it once very hard, and that doesn't matter because church organ voice isn't touch sensitive.

My question is why does the organ get louder with each keypress of the same key? I don't have a real church organ to try, but my old Hammond electronic and Conn analog organs don't even have a sustain pedal and my guess is a church organ doesn't either. Is my CP33 trying to simulate more air pressure in the pipes or something?

Is this behavior common? If I hold down the pedal on the grand piano sound and repeat the same key 20 times quickly, where all 20 notes end before the first note would have ended it's sustain, would that be using 20 of my 64 notes polyphony? On a real piano, I imagine by the time the string was struck about the third time, it would forget the action of the first strike, so I don't think my digital should remember 20 notes. It seems to on the church organ sound though. Maybe real pipe organs have a different sustain action and my cp33 is duplicating it. or maybe it's a software bug.

320 note polyphony on the GEM Promega 3.

I was surprised to see the Yamaha DGX-620 was only 32 note poly as are / were alot of the low/mid Casios.

I,m not an organist but I'm pretty sure they do not have a sustain pedal. By holding down the sustain pedal on your DP in organ voice you are producing sounds not possible on a real organ.

What is happenenig is that since the organ note has no decay, the first note is still as loud as when first struck when you strike the same key again. The multiple tones (when in phase) wil be summed by the audio circuitry producing a louder tone.

You're right - sustain on an organ, harmonium etc is only available through holding notes (with your fingers).

The more advanced DPs out there with multiple layers and zones etc allow you to turn off the damper / sustain selectively. So, if you wanted to play organ over piano, you could disable sustain on the organ voice while leaving normal damper behaviour on the piano part.

VL: So far you are right but the software simulation like Ivory gain some tracks, it will not take long for action manufacturers to come with a controller with excellent action like your CLP-230 or better. And that for less than $1k

VL: you already have the expensive instrument - why would you not use it as a controller as well? I will give a bad, excessive analogy: You have a rolls royce, with a big engine and a trailer kit. You can use the Rolls to trail your boat. But if you are on the market only for something to trail your boat, you are better off looking for a truck instead of a Rolls.
VL: No - but tell me about it? Is there a noticeable lag between your CLP and the sounds played from the cotrolled computer software compared to the sound coming out of your CLP when played as a regular dp?
VL: I am not that evil - But how could you think something like that?
VL: if you are looking for using your "controller" for piano playing only - no essential feature that I can think of. But usually controllers have some features that your DP does not have, like Modulation and Pitch wheels for instance. You might not have any use for those.
Sounds like a good idea to me. I don't believe you need to get a computer as expensive & powerful as some gamers need. A good mother board & CPU, excellent sound card, a lot of fast memory and a decent hard drive. But this is OT and you know all about this.
Just IMHO, excellent post form Seanakaforty why polyphony does matter.

Orez Eno ---------- It's a little obvious that most people-including us-don't know much about DP's and virtual instrument software because of the lack of info when questioned. As for someone using a controller instead of a digital keyboard my guess is one would opt for a keyboard since this is mostly what I see with videos on YouTube with guys using their keyboards with software to get a better sound/polyphony. They use a keyboard because they like the action and/or other functions. That's the route I would take but like yourself have a lack of knowledge when it comes to the details of what and how to hook it all up.

that's changed with all new and upcoming new low end models. all Casio new models have 128 polyphony and all Yamaha new low end models have 64 polyphony.

32 polyphony is becoming history as we speak, though such low polyphony DPs are still on the market.

"that's changed with all new and upcoming new low end models. all Casio new models have 128 polyphony and all Yamaha new low end models have 64 polyphony.

Ok what's Yamaha's problem? why won't they make the jump up to 128?

Isn't that signa's point? That's how I read the post. Yamaha doesn't see the need to go beyond that.

Did I read you wrong, signa?

well they lost me as a customer..until they do
I would've bought a Nocturne for 1399.00 on sale
but its only 64 poly..I think they need to be knock off there pedestal..and then they'll see the light..

I was wondering that myself. I mean, Yamaha is a big name. Doesn't it bother them that they are being passed up by Casio on this?

That's the point, Yamaha is a well known brand, back to the rolls royce analogy. Say you were looking at a basic Ford Coupe (not to bash ford i own one =) and saw that a brand new rolls was only an extra $400 dollars, what would you buy? Granted the ford might have better gas mileage, or a bigger trunk, or Sync, but you'd buy a rolls because of the name, that's why a lot of people buy a lower quality yamaha over a higher quality casio

Vincent L.
Many thanks for taking the time to answer my questions in such detail. I really appreciate it.

I see from your responses that the choice of conventional “controller” versus “piano” is often an economic one. It’s good to hear that there are no technical obstacles that I don’t know about. Of course it makes no sense for someone to purchase a $2500 piano when they know ahead of time that will be using it only to generate MIDI instructions. In my case, I already have the piano and I’m looking for a way to improve it. However, as btcomm pointed out, at this point I know zip about setting up a virtual instrument. So I guess I have a lot of pretty naïve sounding questions. Your responses have helped remove a lot of doubts. Thank you.

Incidentally, a salesman at my local Guitar Center store told me it couldn’t be done based on his experience that he had never heard of it being done. He claimed that most probably a DP does not generate all the required MIDI instructions that the software will be looking for. I suspect he really didn’t know much more than me about virtual pianos.

And, of course, I don’t think you’re evil. But yes, and I know it sounds naïve, but I was beginning to wonder if the type of music played might be an important factor. I’m glad to hear it makes no difference.

Good question. At this point I don’t know for sure because I have not yet setup a virtual instrument. However, I do use piano keyboard entry in my music editor (Finale) and the response seems very instantaneous. I realize that is not a measurable test, but it is encouraging.

I believe my next task down this road is to install some public domain virtual instrument software on my current controlling computer and see if I can get it working. I saw a thread recently that provided a link to a related site. I will try to find that again. A public domain virtual piano may not make my instrument sound any better, but it will give me the technical confidence to go forward with this idea.
The product called Akoustik Piano requires a minimum 1.5 GHz system, but they recommend 3 GHz. Yup, that’s getting pretty close to a game machine, without the high capability graphics of course. Yup, I was surprised also. Synthogy’s Ivory has similar requirements.

Apparently some virtual piano products operate in two modes, a full-blown mode with all the features and high quality tone, and a watered down mode that basically operates and sounds like an old upright at your local bar (yes, I’m exaggerating). I’m told the software is smart enough to decide on-its-own which mode to run based on available system resources. Well, it’s nice to hear that the software may work on my mediocre computer, but I can’t see spending $200 to $400 on software that my machine isn’t strong enough to take full advantage of.

By the way, my current controlling computer at the CLP-230 is an old 800 MHz machine. Obviously it needs to be replaced. In fact, I notice that Finale gobbles up 100% CPU when doing a playback of a score. And that’s just a music editor, not a virtual instrument. But obviously my intentions to run a virtual instrument will greatly affect what kind of computer I replace it with.

For your information, the reason all these ideas have been swimming in my head has to do with the new Yamaha 3xx series of Clavinova pianos to be introduced this year. Many people have already expressed interest in upgrading. But then I started thinking, why do that when for less money I can purchase a new computer bundled with virtual piano software that may sound just as good as the new Clavinova's?

I guess this is the start of a whole new adventure for me. I thank everyone in this thread for this tangential sideline conversation away from the initial subject of polyphony.

Orez -------- I just found this link that might help shed a little light on the subject.

http://www.pianoclues.com/2008/03/15/how-to-use-virtual-instruments-with-your-digital-piano/

sort of my point, and i feel the same way as all of you that Yamaha doesn't bother to upgrade the polyphony for all its models, but Casio is definitely making a run lately, and Yamaha was forced to upgrade to at least 64 polyphony. think about that DGX620/YDP625 has only existed for a couple of years? and now the new 64 polyphony replacement DGX630/YDP635 is on its way. that's how much Casio has been pushing Yamaha, i think, even though Yamaha has always been considered with better quality and technology in DP making over Casio. things are changing obviously...

>>
My first digital, bought in 1989, had
16 note polyphony. My neighbor now has
it, and I think it sounds better than
the latest digitals with 128 and 192
poly.
<<


OOOOOOOOOOKayyyyyyyyyyy...

If you compare a 1989 Clavinova to a 2007 Clavinova CVP-407 and STILL think the old one sounds better, then more LOL to you.

Many thanks. This confirmed the computer requirement, so today I bought a DELL, 3 GHz processor, 4 GB memory, with Windows XP Pro. Cost = $1900. It's a low end game machine. It has a separate graphics card (not shared memory archecture) which will relieve graphics display processing workload from the main CPU, making more CPU cycles available to run software. I know, it’s over twice what I paid for my YPG-625 and almost as much as I paid for my CLP-230. But for a number of reasons I had to upgrade the controlling computer of the CLP-230 anyway. Also, this is probably my last chance to buy an XP machine instead of Vista. I just purchased a Vista machine a few weeks ago and it is terrible. If it wasn’t for this conversation about virtual instruments, I most probably would have bought an under powered machine for less than $1000 to replace the one currently at the CLP-230, and then I would have regretted it when I came around to buying virtual piano software. Computer should arrive next week. I will probably purchase an E-MU 0202 USB Audio Interface to meet the latency requirement for a virtual instrument.

This may have been said, but . .

When you layer a sound, say, add strings, you've chopped your polyphony in half.

When you hold the sustain pedal, each note that is sounding subtracts from total polyphony.

If you have a lot going on, the first sound played will disappear as new sounds are played.

Tone generators (one each for each degree of polyphony) are one of the most expensive parts of the circuitry inside the instrument.

64 seems to be the going amount.


Click on the Roland link below to hear what 256-note polyphony sounds like.

Also, reverb or echo can use up polyphony on older units. I believe that most reverb now is an after-polyphony process.

You can still upgrade a computer that has Vista to Windows XP. Notice I said upgrade. Although, you could lose a few Vista specific functions such as mini LCD screens, etc. I only recommend this if you have a back-up Vista disc in case anything should happen. Happy Pianoing

That is so funny. My own definition of Windows is, “A million lines of undocumented source code that no one can figure out, never mind fix.” Thanks for the suggestion. The machine I’m using to write this message is still running Windows 2000 Pro, and I won’t upgrade.

Or you could find a windows 98 disc =)

Could you please clarify how reverb would use polyphony? I'm not aware of any synths/keyboards dating back to 1989/90 that used any polyphony for reverb (it would be possible to use repeated notes at lower and lower velocities for echoes that would use polyphony, but not aware of any synth that did). They use DSP chips for reverb downstream from the tone generator, so no additional polyphony is involved. If I'm wrong on any of that, please enlighten me.
Clyde

BTW, I believe Windows XP is unable to manage more than 3 GB of memory. So even if your system has more, it won't recognize this.

Don't know whether Vista has this limitation.

Vista 64 bit does not have that limitation. I'm currently running 6 Gb ram (2x2 Gb and 2x1 Gb) on my V/64 bit machine.

Yikes! I just bought a new computer with XP and 4GB of memory. My capacity to make mistakes and blunders continues to amaze me. The computer should arrive next week. I’ll report back then whether I can see only 3GB.

I'm not sure of it being a windows xp problem, but infact a motherboard problem

32-bit computers can address only 4 GB of memory unless you resort to trickery. Hardware devices require a part of this space and that's why Windows doesn't let you use the full 4 GB. (In fact, Windows takes up about half the available space for itself, although you can change it to use less.)

As DPs move to more advanced physical modelling they will use more polyphony. An example is sympathetic resonance: hitting a single key no longer just uses two voices - it also triggers notes on all the harmonics. This means each key pressed might need at least 8 voices for the next 3 harmonics

With enough keys pressed, at some stage all strings will be resonating. Does this mean the highest polyphony that you will ever need on a DP is 88x2 = 172 voices?

This question was asked, but never really answered. A polyphony limitation is only applicable to a specific piano, correct? If you use a module or software piano, that limitation is gone?

To make a more concrete example, the Casio PX-320 has 128 note polyphony and costs $700. The older Casio PX-310 has only 32-note polyphony. But it only costs $400. So the 310 is more limited than the 320. But if using it only as a controller, it makes no difference, correct?

Yes, I'm about 99% sure that is the way it works. The polyphony possible is based on the receiving synth engine, not the MIDI controller.

Absolutely correct, it is whatever the polyphony limits are of the receiving synth engine. You could of course use a synth for a controller and if you also used it's synth engine for sounds (i.e. local control on) in addition to your receiving synth module/software, then the synth used as a controller can run out of polyphony for it's own generated sounds but will not affect the receiving module/software polyphony. I hope I made that clear enough, let me know if I did not.
Clyde

My old old keyboard has 8 generators and was easy to fill up, esp. on 'Pipe Organ' setting that used 2 generators for each key. Easy to have more than 4 keys on, esp. when changing chords. The suppressed tones were unpleasant to hear.

So from what I gather is that ; when it comes to total polyphony being used ; the formula is this: Total Polyphony = layers + features + voices + styles + midi sounds + stereo + chords + individual notes
I might have missed something. How many years now that polyphony has been a feature on Dps? And no company as yet has NOT decided to add to their tiny screen display; "Amount of Polyphony Presently being used in this song " = 47 ? !@!@!$%^%#@!
or " You have presently gone over the polyphony limit, would you like to proceed?" Yes or NO ?

I think the manufacturers have not addressed a readout of how much polyphony is being used is due to the fact that for the average user it is not really an issue. Most people that run out of polyphony do so because they do not realize how to use their equipment properly. I can play all day long on my 32 note polyphony synths and never have an issue, even when using several different sounds at the same time. Based on posts I see in many different forums the biggest issue arises from over use of the sustain pedal. How many notes do you need to sustain while continuing to play new notes? Twelve? Twenty four?? At what point do you have a garbled mass of sound rather than music? I see posts from people all the time that complain they are running out of polyphony when their synth/DP has 128 note polyphony, I think they just need to learn how to use their gear properly. How much polyphony is enough? 256 notes? 512 notes? How much additional are we willing to pay for adding the hardware/software resources to allow monstrous amounts of polyphony?
Clyde

Orez, Even 2 gigs of RAM should be enough for a sampled piano. Some developers are recommending a hard drive that spins at 7200rpm. You might want to check the specs on your new machine.

Re running a software piano, unless your new machine is already spec'd with a soundcard which has a broad dynamic range, you'll need a third-party sound card and either quality external speakers or/and studio-quality headphones, to experience the true quality of your software piano.

When auditioning demo tunes, my ears prefer ones which do not include a lot of reverb and which do include exposed notes played slowly. Demos of the "Let me pump you up" variety may make a strong first impression, but that kind of instrument would quickly get on my nerves.

If I understand correctly, polyphony is constantly changing throughout a song. So your first example doesn't seem very useful. The second example seems downright awful. You expect the synth to stop in the middle of a song to ask?

Pianoteq, a software piano, does this. I was a little surprised to see that I easily managed to play about 48 tones at the same time just by banging out a few chords. Nothing too fancy.