Comparing digital pianos

[Dave2002]

Right now some of us may be indulging in retail therapy - as there's not so much else to do. Or at least virtual retail therapy - which is cheaper! [i.e. no money is involved!]
This can be harder without being able to get any hands on experience - particularly when comparing things like digital piano keyboards.

I have previously - before the Covid-19 thing got out of hand - tried a few pianos/keyboards, and I thought that maybe a new one might be a good thing to have.
I have watched/listened to quite a number of Youtube reviews. Obviously it's not possible to get an impression of the feel of a keyboard by a video review, but one might get a sense of the sound.

Here is one - https://youtu.be/ujim0BfT_As - but this shows something which I have suspected for quite a while - though maybe it's my hearing.

Basically - yes some of the reviews - particularly for instruments like the Yamaha p125 - appear to demonstrate a greater depth of sound in the low end of the instrument - which might be impressive to some, but my concern is that to me the apparently deeper bass notes actually seem slightly sharp. In this video, the Roland instrument does seem to me to have better tuning at the low end.

So - am I imagining this? Is it something to do with the way notes are sampled, and decayed on a digital piano?

[Jonathan]

I can only comment as someone who used to work in a music shop (albeit years ago) and nothing, no matter how expensive it is, even now, to my ears, sounds as good as a proper acoustic piano.

I did play a stage piano a few years ago at a Christmas function for my workplace and it was terrible.

[Roslynmuse]

I can only comment as someone who used to work in a music shop (albeit years ago) and nothing, no matter how expensive it is, even now, to my ears, sounds as good as a proper acoustic piano.

Agreed. I'm spoilt in my normal work setting at using mainly Steinways and some good Yamahas, but even a basic upright decays and resonates in a different (and more predictable) way than expensive digital keyboards. I'll listen later to the examples Dave has posted re the tuning issue.

[Dave2002]

I can only comment as someone who used to work in a music shop (albeit years ago) and nothing, no matter how expensive it is, even now, to my ears, sounds as good as a proper acoustic piano.

I did play a stage piano a few years ago at a Christmas function for my workplace and it was terrible.

I'm sure you are right - though the acoustic pianos do have to be tuned. We currently have two - and both have "interesting" tuning at the moment, as well as a slightly uneven action in parts. So you have to compare the digital with the acoustic under real world conditions. I might prefer to play a reasonable digital one to an out of tune acoustic one.

Another factor which we have noted in the last year or two is that the acoustic pianos may have a heavier action - nothing wrong with that - except that older people who may be developing problems with their hands might find them more difficult. I believe that many of the digital ones tend to have a lighter touch - though some are heavier than others.

The manufacturers and vendors claim that they have made great improvements in recent years to the sound, and other aspects. A digital piano is probably better than no piano at all. I have heard some played in concerts, and really I thought they were dreadful - which fits in with your views.

Our two pianos are both vintage - and a bit decrepit - a Rogers upright and a Reinhold small grand. Probably both around 100 years old.

[Ein Heldenleben]

Once spent an hour in Yamaha shop in Soho and played their hybrid digital pianos (not the clavinovas ) and was particularly impressed with the grands. But not as good as an acoustic U1 or U3 . Didn’t notice any tuning issues. The digital keyboard ‘ pianos ‘ I wouldn’t bother with unless it’s for rock / jazz / gigging. You’ll soon get tired of the sound. The touch on the hybrids is identical to an acoustic piano. If you are prepared to get a tuner in he / she can adjust the key pressure.

[Roslynmuse]

Here is one - https://youtu.be/ujim0BfT_As - but this shows something which I have suspected for quite a while - though maybe it's my hearing.

Basically - yes some of the reviews - particularly for instruments like the Yamaha p125 - appear to demonstrate a greater depth of sound in the low end of the instrument - which might be impressive to some, but my concern is that to me the apparently deeper bass notes actually seem slightly sharp. In this video, the Roland instrument does seem to me to have better tuning at the low end.

Yes, the bottom notes sound sharp to me too; even on the Roland, which sounds closer to a 'real' piano tuning, the final low A sounds sharp.

[Eine Alpensinfonie]

Right now some of us may be indulging in retail therapy - as there's not so much else to do. Or at least virtual retail therapy - which is cheaper! [i.e. no money is involved!]
This can be harder without being able to get any hands on experience - particularly when comparing things like digital piano keyboards.

I have previously - before the Covid-19 thing got out of hand - tried a few pianos/keyboards, and I thought that maybe a new one might be a good thing to have.
I have watched/listened to quite a number of Youtube reviews. Obviously it's not possible to get an impression of the a feel of a keyboard by a video review, but one might get a sense of the sound.

Here is one - https://youtu.be/ujim0BfT_As - but this shows something which I have suspected for quite a while - though maybe it's my hearing.

Basically - yes some of the reviews - particularly for instruments like the Yamaha p126 - appear to demonstrate a greater depth of sound in the low end of the instrument...

I bought a Yamaha P115 three years ago, along with a stand and pedal set, to use as an accompanist at venues without a piano. It’s remarkably good value for money, but I agree that the bass is artificially boosted. I can’t think why this was done.

Regarding hybrid pianos, I decided to sell my beautiful Steinway Model K when my circumstances changed and I had to move into a terraced townhouse. I replaced it with the best hybrid piano on the market; the Yamaha AvantGrand N3x. This involved some considerable swallowing of pride, following my comments about “fake” pianos, but it’s quite superb to play, and really feels (and looks) like a real grand piano. But if I could, I would still prefer the real thing.

[Dave2002]

I bought a Yamaha P115 three years ago, along with a stand and pedal set, to use as an accompanist at venues without a piano. It’s remarkably good value for money, but I agree that the bass is artificially boosted. I can’t think why this was done.

The current rough equivalent of the P115 is the P125 - which I have been considering. I have also thought about the Casio PX-S1000 - one of which I bought last year. That one does have a number of advantages, it's very slim and compact, and can run off battteries and the sound is probably as OK as most of these things are.

After reading some of the replies above I thought I'd actually go back to tinkling on the Reinhold piano I mentioned. That's arguably a real piano - though one piano tuner thought it was dreadful and started commenting on the action and other flaws. Maybe it's not great, but another friend who's quite a good pianist tried it and when I said we were thinking of getting rid of it she said "Don't do that - it's got a really nice sound". Anyway I quite enjoyed feeling my way around it again - though the one or two notes which are really out of tune are a problem - which no doubt could be fixed eventually. So even an old acoustic piano can possibly be better in some ways than many of today's low to mid range digital "pianos".

If I decide not to bother with yet another digital piano that's going to give me another problem - what to give as a present! Current possibilties include a compost bin ...... !!!!

[ardcarp]

I personally dislike digital 'pianos' though I concede that they have advantages e.g. for itinerant musicians or in flats, where the real thing just isn't possible. However I've always wondered about their life-span. I know nothing about electronics. But I know a few people that have proper pianos which are still playing and sounding good after 100 years. Not many things one buys last that long!

[rauschwerk]

I personally dislike digital 'pianos' though I concede that they have advantages e.g. for itinerant musicians or in flats, where the real thing just isn't possible. However I've always wondered about their life-span. I know nothing about electronics. But I know a few people that have proper pianos which are still playing and sounding good after 100 years. Not many things one buys last that long!

30 years ago I bought a Technics PX-107 (as used for practice purposes by Peter Katin, late of these boards). It served me well for most of that time, but then it packed up and I was dismayed, as by that time Technics had abandoned the musical instrument market. Luckily, I tracked down a repairer in Guildford. I sent the printed circuit boards to him and he repaired them: apparently they were corroded! Now the action is getting noisier, but I can live with that as my serious piano playing days are drawing to a close. I imagine that pianos like this could be engineered to last a lot longer than 30 years but no doubt that would increase the price many times.

A digital instrument is just the job for easy transposition if you accompany singers a lot, as I once did. I used to take it on gigs: it was often a lot better than the pianos in the churches and halls I visited.

[mikealdren]

Interesting comments on pitch inaccuracies because that's one area where digital pianos really ought to be perfect and never change. I wonder why they are not, have you tried asking Yamaha?

[Cockney Sparrow]

Sorry to ask a question, as a very uninformed person on the merits of pianos. Isn't reproduction of Bass frequencies by speakers something of a challenge - IIIRC a large bass cone is needed, really, if the best bass reproduction is needed. Or perhaps the best, most neutral sounding headphones are being used?

I presume Yamaha, for example, should be able to produce a decent amplification/dac to the the speakers/headphones......

[ardcarp]

it was often a lot better than the pianos in the churches and halls I visited.

I agree with you there, as I suggested in my reference to "itinerant musicians" above. Digital pianos certainly have their uses. I'm quite intrigued as to when the expression 'stage piano' came into use to describe electronic instruments. I first heard it about 3 years ago from one of my daughters (who teaches music). At first I thought she just meant the piano that happens to be on the stage!

[Bryn]

https://en.wikipedia.org/wiki/Stage_piano

[Dave2002]

Interesting comments on pitch inaccuracies because that's one area where digital pianos really ought to be perfect and never change. I wonder why they are not, have you tried asking Yamaha?

There might be several factors in an explanation. One might simply be that we all perceive pitch sightly differently. Most musical sounds are not siimply one single fixed frequency sinewave. A typical modern piano will have three strings for the bass notes, and hopefully they will all be ore or less in tune - otherwise there'll be beat effects. However, I believe that changing the frequencies of each string slightly can give a weightier sound, but it can't be overdone to avoid the strings sounding very out of tune. Additionally there will be cabinet resonances within the instrument.
So effectively each note is not quite a pure and simple sound (which would actually be rather boring) but a composite - and it's not unreasonable to expect that different people might experience a slightly different sense of pitch on the same note. Also the pitch sensation may depend on how loud the sound is - I think it's very complicated.
OK - that's one possible factor.

Another is the way that digital pianos function. They mostly use sampled sounds from other instruments, such as acoustic pianos. Typically the recordings are done both with and without abience (sound from the surroundings of the instrument). Sometimes sounds from several pianos are merged together to provide the base set of samples. Sometimes frequency correction is also applied to the sampled recordings - ostensibly to make the pitch more accurate. This is done by mathematical algorithms, and different manufacturers may use different algorithms - or rely on different recording studios to do this work.

That process only leads to a very approximate piano sound, however. The sound of an acoustic instrument changes depending on how hard each note is struck. So rather than using a simple code - based on the 88 keys of a standard piano - which would be of the form Key(A4) - play Sample (A=440) - which would only require 88 processed samples, digital pianos also take into account the apparent loudness and decay of each note. This can be done by expanding the sample range - for example recordings of each note in different modes - Struck very hard, Struck hard, Struck moderately hard, Struck moderately, Struck fairly lightly, Struck very lightly etc.

Also the recordings could be done with the pedals down thus giving extra resonance if the sustain pedal is depressed, with a longer decay, and a quieter sound if other pedals are used.

If all the combinations are used, then there will be very many samples recorded.

Then the playback of the digital samples has to be coupled to the actual keyboard used on the digital piano, which must be capable of detecting the velocity/force with which each key is pressed. So this is now getting quite complicated.

There are cheats which digital piano makers can use - and certainly have used in the past. First, it's possible to shift the pitch of a sample in real time, so some instruments have done this. Rather than record all the sounds for each key on a piano, only record some of them, so for example, record the sound for middle C, but if a C sharp or B is needed, then simply shift the sound of a C sample up or down a bit.

That reduces the data required somewhat, a factor which was certainly important in the past when computer storage was more limited and expensive.

Another "cheat" is to somehow blend the constructed sound, so if a piano maker has only recorded middle C and the G below, then to get a B flat that could be obtained either by taking the middle C sample and shifting it down two steps, or take the G sound, and shift it up 3 steps.
Some designers might decide to blend both those two generated sounds - in some proportion.

That still only gets the piano design a bit further - and probably most good electronic pianos don't try to economise on samples so heavily these days.

The next step is to start linking the different volume levels - but if that is done crudely that leads to a very grainy sound - with unpleasant jumps in dynamics. That is where another real time adjustment is brought in, with adjusting the volume level of each note to give a smoother change from loud to soft tones.

For very long sustained notes - which you'lll note can't really be done on a piano - but can be done on instruments like organs, a long sample might not be recorded, but rather parts of the sample will be looped - very possibly at different levels of volume.

Lastly (for the description here - but there might be other tricks used) - digital piano makers thought that users could notice some of these tricks, such as looping samples, so they introduced techiques such as round robin sampling, in which different samples are used for each occurrence of a key press. They might indeed be cycilc round robin sampling, but perhaps even better is to use randomised sampling.

So by all of these methods the digital piano makers manage to produce something which is a moderate approximation to a piano sound, and which is linked to a touch sensitive keyboard which hopefully is sufficiently sensitive and accurate that many people will be reasonably happy with the results.

On top of all that the there is the analogue amplification and speaker output to consider - which also make a difference to the sounds. Just consider the sound of different - some very good - recordings of pianos, played through different "hi-fi" systems.

I'll leave it there for the moment.