Why not the piano as a reference for bass

To my hearing,the lowest bass of the piano lacks the texture of a stringed bass..It strikes me as the kind of one note,thump thump bass you hear coming from a ricers trunk..
 I will however note that when it comes to physical weight & body,the piano is my benchmark..

@freediver what piano are you listening to that sounds like that?

Personally, I think it is because piano live is amazing but it is difficult to reproduce well, so most systems would fall short.  I have learned that over the years about horns.  I tend to agree with you though.  A good sample of test songs should include horns and piano to test a system’s ability to enjoyably reproduce those instruments.  I don’t listen much to piano, just not my thing, but have really started to enjoy horns - feels odd to even type that because when I first started my system made horn sound terrible.  

Piano goes low but wave length impact too short 

A pipe organ much better there 

Depending on music type 

The shortness of the piano tone is the point. Stopping the overhang in the bass is a major problem for most speakers and the piano is a great test for this.

@freediver 

The piano is a stringed instrument. It is one of the best to evaluate gear. If our gear can't make a piano sound real, we are missing something. I don't know the lowest note on a piano (in hz) but it is quite low. Cello lowest notes are 30 hz, I believe, also a nice indicator of how your system sounds. Pipe organ is probably best for the very lowest notes or some synthesized music as there is pretty much no limit to what digital is able to do. Lowest pipe organ notes are 8 hz from 64 foot pipes but more recordings will include 16 hz from 32 foot pipes. It's the lowest I've heard on a recording (D2D vinyl).. I believe the piano is one of the toughest instruments to reproduce through a stereo system and many do use it as a reference, including myself. Not necessarily for the bass but the bass is indeed quite low. 

I think that the "attack" has a lot to do with it.  Whereas a bass is "plucked" by hand or played with a pick, a piano is struck with a felt-covered hammer and this presents a completely different "leading edge."

Steinway, Baldwin, Yamaha,  Grand, Spinet.....they all sound different

Double bass can go as low as 31 Hz, but only on five-string instruments or when equipped with a low C extension. The lowest note on a standard four-string double bass is typically an E1, which vibrates at approximately 41 Hz. However, some five-string basses have a low B string (tuned to B0), which is around 31 Hz. Similarly, some four-string basses have a low C extension that can reach down to 33 Hz. So double bass is a good instrument as a reference for low bass.

On  the other hand, yes piano can go as low as 27.5 Hz. However, modern piano started to take its present form much later than Beethoven or Mozart time periods. While the specific frequency of the lowest note on Beethoven's piano is unknown, the range was limited compared to modern pianos. The lowest note was typically F1 (around 43.65 Hz) or C1 (around 32.70 Hz), depending on the instrument. So typically one may not hear the lowest note of the modern piano when listening to Beethoven or Mozart's works. And I am not 100% sure how many times one will hear the lowest note in jazz piano either, but I could be wrong.

Hence, in my opinion the double bass is a more reliable reference of the bass than piano considering the how often one can hear these lower notes. One can clearly hear the purring of the double bass in jazz ensembles most of the time right in the middle of the sound stage. It would be interesting to hear from those who know how often one hear the lowest note of the modern piano (27.5 Hz) in classical and jazz music. 

The difficulty in using piano as a reference for bass response is that very few pieces stay down in the low bass for long enough. And the bass part is usually complementary to what's being played in the right hand so cognitively it's difficult to just listen to the bass part by itself. And if it' a grand piano, it usually has a lot of reverberation so the ADSR envelope of the notes is very different to an acoustic or electric bass. But of course, piano is still useful for gauging the bass response of system at frequencies that a string bass does not reach. Synthesisers are arguably even more useful. 

Okay so I didn't  clearly articulate my opinion of the extreme low bass on the piano..YES I know it is a stringed instrument but again I stand by my take on it's lack of texture compared to a plucked or bowed bass..
 I believe @toddalin reply explains exactly why I hear it as one note thump thump instead of the resonating,detailed and expressive bass I hear from say a cello or stand up double bass..

problem with the piano as a particular bass instrument is its relative lack of portability. that aside, unless it is miked closely, the bass fundamental lacks sufficient volume to poke through a dense mix. that said, the Beatles used the left hand piano notes as the bass line in at least one song ["for you blue"], and pianist Jess Stacy used his left hand as the bass line in several songs performed in concert with Benny Goodman at his seminal '38 Carnegie Hall jazz concert. unfortunately in that case the abysmal recording quality resulted in Gene Krupa's booming kick drum and floor tom drowning out most of Stacy's otherwise well-done bass line.

I still think of Ray Manzarek playing all Doors bass lines on his foot pedals.  Always correct bass, always Awesome.  Still play them occasionally.

Gimme the bass at about the 9 minute mark of Russia on Ice by Porcupine Tree, audiophile nerds.

Actually, no..., Ray played a Fender Rhodes Piano Bass with his left hand.  He never played pedals.

In several of their tracks, he is overdubbed by a bass guitar.

https://youtu.be/Fiq9VDkGVnI

@freediver 

As we all know, a piano is a percussion instrument.

It's Geddy Lee on the Moog Taurus if you want bass pedals in rock.

I understand the Bosendorfer Imperial piano has an extra register at the bottom end of the scale and will play down to 16.5Hz.   I’ve not heard one on a recording, but my College had one in the Hall, and it was mighty powerful when well played!

@Freediver, thank you for reminding me of this.   Now I’ve got to hunt for a recording!

@freediver 

I wasn't trying to give you a hard time. Just struck me as funny that you wouldn't think of a piano as a stringed instrument and I know that you realize that it is. As others point out, the deepest bass notes on the piano are often accompanied by other notes and are often short in duration, unless the sustain pedal is used for more than a second or so. I'm sure we all know all this stuff. Also, pointing out the new Bosendorfer and I think some other makers having the extended bass pianos. I've not heard one yet except on computer video, doesn't quite do it justice. 

This is all interesting reading. 

@guscreek  Interesting question.

Hence, in my opinion the double bass is a more reliable reference of the bass than piano considering the how often one can hear these lower notes. One can clearly hear the purring of the double bass in jazz ensembles most of the time right in the middle of the sound stage. It would be interesting to hear from those who know how often one hear the lowest note of the modern piano (27.5 Hz) in classical and jazz music. 

@toddalin  Terrific answer. Do you play?

Played clarinet from 5th through 12th and keyboards in a garage band in the late 60s early 70s.

Had equipment to die for back then (Hammond, Hohner, Vox, Farfisa, Moog and EML synths), but sold it off to pay for college. 

Another thought on the topic.  You hear basses go down to their low E-string literally all the time, so people have a feel for it (did someone say reference?).

But how often you you hear a piano playing low A?

After seeing Dick Contino I took up the Accordion. By the fifth grade the Clarinet was the only instrument open. I simply didn't practice enough and got the boot. Devastating at that age. Meh...

When I got to High school Paul Jackson soon to be Herbie's Bassist on Head Hunters was playing upright in the school combo. Why he took the time to introduce a freshman / surfer to the Bass took me a while to understand. He later mentioned quarter notes were the first notes I played without any coaching. Sweet man.

B3? My aching back. 

As to the Doors, I would hope that one's system allows them to differentiate the sound of a bass guitar...,

https://youtu.be/ptA39Awo0FE

and a Rhodes Piano bass...,

https://youtu.be/nOJSmXSFCWk

It should also be obvious as to whether Ray is playing a Hammond, a Vox, or a Gibson organ in each cut.

Piano bass limited in bass energy and duration and thus limited to be used in evaluation.  However, if piano bass is individually important, no reason for that particular person to not target piano bass excellence.

Also, bass preferences can differ - some seek bass energy, while others target better fidelity

The late great Oscar Peterson was gifted a Bosendorfer late in life and he used that low register a lot.  If you can find recordings by Telarc you might hear it.  Also the series "Exclusively For My Friends" originally recorded on BASF in the Black Forest has him playing on a Bosendorfer that I believe has those low notes.   There is also a great recording by Ahmad Jamal entitled "Ballades" on Harcourt of Paris that captures the full scale of the piano magnificently.  

Piano is great and offers something Bass fiddle does not!  Check out recording such as Jin Ju playing Schumann Fantasie in C opus 17 (available on Qobuz) 3rd movement, between 2:20-30 min mark, Steinway 1901 Concert Grand Piano D per the liner notes. 

…the Piano can play bass notes quietly (hence the full name of the instrument - piano forte).  While these low notes may seem anti-climactic for some, the low register of a good piano has an attack to it, especially when played softly, that is beautiful along with tone and overtones, and decay of the note.  A fiddle is generally played loud and consistent in attack, and generally all the low notes all the time (so it’s convenient for use in evaluation as well as what the instrument offers in its own right), whereas piano is playing usually higher notes as well and more often.  So you need the right recording.  I’m not saying a bass fiddle can’t play notes quietly but the piano is pretty unique in what it does.  If a system can produce these notes well, it is challenging.  “One note bass” from some drums or techno or pop music is one indicator of bass but misses a lot in sonority and tone.  

Testing bass response with piano music is a good test- even for integrating subwoofers. 

However it is too limiting and will not reveal other musically important bass qualities that one looks for.  

Great post and comments.  I also wondered about this too. Having access to a Grand and a choir (church) playing weekly, I get to listen to the Grand. I believe based on my hearing, i can get close BUT not the same, no matter what format i use.. Yes the lower registers and overhangs is where there is a noticeable difference.

@toddalin 

Whereas a bass is "plucked" by hand or played with a pick, a piano is struck with a felt-covered hammer and this presents a completely different "leading edge."

If we are talking double bass, in most classical music it is mainly bowed and in a big orchestral piece there might be eight or so playing in unison. There is no other sound like that with as much character!

I find piano recordings to be largely unrealistic- either too closely mic’d or a portrait in miniature but often lacking the gravitas of a big concert grand. I’ve had some large concert sized grands in homes- there is a growl to the lower bass that is not evident on most recordings. I use piano recordings (a few select ones) to judge the attack and decay envelope of a system. I typically use simple recordings of small combo jazz to evaluate how "real" the bass sounds- I’m a big fan of Cecil McBee-- almost every record he appears on has something interesting and I’ve gotten my system to the point where the bass sounds very filled in and dimensional, not just a faint hologram, and you can hear the positioning of the instrument relative to others on the stage as well as its height-- very convincing sounding as a full-sized instrument. This was the result of a bigger room, the use of a pair of DSP’d 15" subs that were dialed in by ear after some basic measurements and a change of phono cartridge that gave me the gravitas that seemed to be lacking using Avantgarde Duos and Lamm ML2s. 

Pianos are percussion instruments according to the Hornbostel-Sachs system of categorizing musical instruments. It belongs to the percussion family because it produces sounds by striking the strings with a felt covered hammers. It is often miscategorized as a string instrument because it has strings. A pipe organ is the better choice for testing bass response. A Pipe organ which is a wind instrument, can produce very low notes, all the way down to 16 Hz, which is lower than what most full-range speakers can reproduce without a very good subwoofer.

alexlewis3

Pianos are percussion instruments according to the Hornbostel-Sachs system of categorizing musical instruments. It belongs to the percussion family because it produces sounds by striking the strings ...

You are mistaken. The piano is classified as 314.122, considered a "cordophone" because they "produce their sounds by means of the vibration of a string or strings that are stretched between fixed points." More info here.

Percussion instruments are classified idiophones.

@richardbrand 

https://youtu.be/XBXUP5GqYJs

I was once tasked with designing a speaker system for amplifying electric piano. So I had to figure out how low in frequency the speaker system needed to go.  Well it turns out that the fundamental of the 27.5 Hz low-A is down in level so much that it is of negligible audible significance.  And, likewise its first overtone at 55 Hz!  In fact a piano's lowest audibly significant frequency is the 62 Hz first overtone of low-B.  So that was my target, and the customer liked the cab enough that he ordered a second one. 

Anyway, my point is, while piano DOES have very low frequency fundamentals, the energy of those fundamentals (and in some cases even their first overtone) is so low in level that, imo, piano is not really a suitable instrument for evaluating a speaker's bass response.

Duke

@toddalin 

https://youtu.be/XBXUP5GqYJs

Yep, that bass is a plucked double bass but on the released track it was 'doubled' by a bass electric guitar, according to the clip.

My point was that there is much more you can do with a double bass than just pluck it.  With classical music you can go to concerts which are not subject to electronic manipulation so there is a real reference for judging reproduced sound quality.  A bowed double bass will make all your drivers work hard, including the tweeters!

One of the interesting things about the piano is that the pianist’s ’touch’ does not alter the harmonics present in the note being struck.  The best example I can give of this is the astonishing recording of Grieg’s Piano Concerto released in multiple surround sound formats by the Norwegian label 2L.no - see GRIEG Piano Concerto - Percy Grainger, Kristiansand Symfoniorkester, R – 2L Music Store

Originally recorded on piano rolls in 1921, the new recording has a full symphony orchestra and a modern Steinway piano, played mechanically!

This is one of those unusual recordings where both the performance and the sound quality are superb.  Percy Grainger was a very interesting character, being Australian, a pianist, a composer, an athlete and a sadomasochist.  His ideal instruments would have been synthesizers, but they were yet to be invented.

I can’t let this go without mentioning the Australian designed and built Stuart and Sons’ Concert Grand Pianos, some of which extend the ’standard’ 88 note keyboard to 108 keys with the lowest note a subsonic 16-Hz

@audiokinesis 

I was once tasked with designing a speaker system for amplifying electric piano

No doubt the electric piano was attempting to sound like a real piano?  When I play the lowest note on an acoustic piano, the amount of sound energy output is pretty directly related to how quickly I press the key.  There is no artificial limit, and no shortage of sound either.

The key mechanism is mechanical, not some electronic switch or sensor.  And the whole piano resonates

@richardbrand , my investigation into the loudness of the fundamentals and first few overtones of the lowest piano notes was based on the spectra of those notes played on a grand piano, as I figured that would be applicable to amplified electric piano.

I presume the electric piano was "attempting to sound like a real piano".  My  customer said that he used the same model electric piano as Elton John.  He mentioned it to me but I don't remember the specific model.  I think it was a Yamaha. 

@audiokinesis 

Thanks for the clarification!

I don’t agree that the low notes on a modern grand piano (piano-forte or soft-loud) contain so little energy that they do not merit being reproduced.  Bosendorfer and Stuart keep extending the keyboard downwards!  I don’t think Beethoven would have agreed either - he was very quick to extend the range he wrote for when gifted pianos which went further up and down!

There is of course a fundamental difficulty in judging sound quality against amplified sources - there is no original to compare to.

Anyway, I use soft piano music to judge atmospherics and double bass for bass impact ... but the main thing is to enjoy your music

@richardbrand wrote: "I don’t agree that the low notes on a modern grand piano (piano-forte or soft-loud) contain so little energy that they do not merit being reproduced.  Bosendorfer and Stuart keep extending the keyboard downwards!"

Just to be clear, I’m not saying that the lowest notes on a normal grand piano contain so little energy that they do not merit being reproduced. 

I’m saying that the lowest fundamentals (and sometimes the corresponding first overtones) of the lowest notes of a non-Bosendorfer grand piano contain so little energy that they do not merit being reproduced in a live music setting. 

I don’t know whether this is a grand piano or not, but it shows the spectra of the lowest notes starting with A0.  Pause it after each note and look at how much energy is in the fundamental and first overtone:

piano sound spectrum - YouTube

Anyone else interested in why piano might or might not be a good instrument for evaluating a speaker’s bass response is invited to do the same.   There’s just not a whole lot of true low bass energy. 

@audiokinesis

piano sound spectrum - YouTube

From the comments, the guy who posted that video had no idea what microphone was used, let alone what piano or where the microphone was positioned! 

What I do find interesting is the low modes that are excited when high pitch notes are played.  As I wrote above, the whole piano resonates - after all, it is filled with more than 88 tuned resonators and felt can only damp so much.

Sure the low notes also carry a lot of harmonics, which is why the piano sounds like a piano and not like a pure pipe organ. Agreed, many people may not hear the fundamentals of low notes, and few indeed will directly hear the 16-Hz fundamental of a 108-key Stuart piano's lowest note.  Few subwoofers will even go close with any sort of accuracy. Same goes for the 8-Hz fundamental of Sydney Town Hall's organ with its 64 foot long Gravissima pipe.  You can't hear it but you can certainly feel it!

I have always used well recorded piano compositions as an analytical tool for determining system. I will attempt to explain how I use piano recordings as an analytical tool.  Rather than concertos and symphonies, it is best sonatas.  I have some sonatas that, rather than solo piano, add a violin.   That is in my opinion the best analytical tool.  So how and why? …

Crossover and Driver Integration:  The piano, as others stated, is a singular instrument covering a broad frequency range.   Problems with speaker driver integration and crossover design, or issues with ragged frequency response of electronics become easily evident by using well recorded piano recordings.  As an example, in my past, I had hybrid Apogees.  The lower piano registers were slow and smeared compared to the wonderful midrange and highs.  
 

Dynamics:  While not the best test for percussive crescendos or rock dynamics, the piano by definition as a percussion instrument, is one of the best instruments to use for analyzing system dynamics, especially microdynamics.  While I agree in part with @audiokinesis that the fundamental and first overtones do not have the same impact as other instruments, well recorded closed miked piano will have strikingly vivid first wave percussive impact.  The real value is in analyzing the microdynamics of secondary harmonics and how ppp notes are developed in a composition.  
 

Detail Retrieval:   Well recorded piano is an excellent test for detail retrieval including, harmonic decay, the sound of the hammers vs the strings vs sound board, as well as how the notes decay into the venue.  Piano recordings can easily discern engineering techniques such as close miking vs far miking.  A well designed audiophile system should be able to discern these attributes of well recorded piano.  Here, combined with my discussion on dynamics, is where the piano is excellent for bass analysis.  Analyze bass note first wave (fundamental impact). Is it sharp and striking.  Analyze how it decays and the sound of all the secondary harmonics.  Determine if you can discern the hammer strike from the string sound and sound board.  This is an excellent test for comparing equipment.    
 

Imaging:  Closed miked piano recordings will be able to develop an image that shows the position of the mike relative to the keyboard.  Image palpability will be evident.  
 

In conclusion, piano recordings are an excellent analytical tool in general, and for bass as well.  Yes, you will need to use other records of other instruments to analyze bass impact, but these others are not as good for bass detail and especially for bass integration.  
 

Apologies for my usual pontifications and typos in advance.  

@richardbrand 

Have you witnessed the 64 foot pipe? I've always wondered what the experience would be like. You probably never hear/feel that pipe by itself so maybe hard to describe. I'm sure you do feel it but it's hard to imagine hearing nothing at the same time. Am I making any sense? Just curious about this and have started conversations before about what we can hear/feel below 20hz. I have read that in some instances, some people are able to hear down to 12hz. I heard 17hz on my system with a test record, rather subtle but there. Nothing below that and nothing felt, probably just exceeded system capabilities. Played louder, I might have heard something, hard to say. Anyway, fun stuff. 

Thanks All!  I could not be more pleased with the results of this thread.  Great facts, expressed practical experience combined with differing informed opinions.  Throw in the consistent civility to top it off.  I look forward to reading  posts as more seem to keep coming. 

@billpete 

Have you witnessed the 64 foot pipe?

Alas no!  I am slightly friendly with several organists in Sydney but none has hinted when that 64 foot monster might be exercised.

Mostly I hear church and cathedral organs, and the refurbished beast in the Sydney Opera House.  Olivier Latry, the organist from Notre Dame in Paris, featured in Saint-Saens Organ Symphony and Poulenc's Concerto for Organ, Strings and Timpani - one of my personal favourites.  The next day we went to his organ masterclass at the Opera House.  It is amazing how each student had a USB stick with their personal settings for the organ configuration.  I'd like to build a relational database representing that organ and its multiplicity of parts.

I have heard a piano recital given on a Sturt and Sons concert grand piano, but not the full 108-key model.  The Australian Broadcasting Corporation released video and CDs of Beethoven's Piano Concertos played on a Stuart piano.

@audiokinesis 

I’m saying that the lowest fundamentals (and sometimes the corresponding first overtones) of the lowest notes of a non-Bosendorfer grand piano contain so little energy that they do not merit being reproduced in a live music setting. 

I want to try to nip this idea off, here and now!

Just try this little experiment.  Find yourself a mechanical (not electronic) piano and play the lowest key.  You will hear the fundamental note, plus overtones.  To discover what the first overtone sounds like, move up one octave and play that key.  If the two notes sound as if they are the same frequency, then you cannot hear the lowest fundamental.  But my experience on a Kawai upright piano is exactly the opposite, the lowest note is clearly an octave lower and is clearly audible.  Just in case somebody suggests that the fundamental one octave up is also inaudible, hop another octave up and repeat.  They cannot all be inaudible!

Why an octave? An octave is just double the frequency and in Western music there are eight white piano keys spanning an octave (which is why the Latin for eight features in its name).  There are seven white keys and five black keys before each octave pattern repeats - 12 notes in all.  When Pete Townshend said he chose his double bass for the session, he doubled his pay by doubling this on an electric bass guitar 12 notes higher.  Had me a bit confused but he was just playing one octave up, something very common in orchestral pieces where cellos double the basses, the picolo doubles the flute and so on.

The physics of the fundamental vibration of a string are well known.  The vibration frequency depends on the length of the string, the mass of the string and the tension in it.  The fundamental frequency is where the entire string between its fixed ends moves in the same direction.  But there is another mode, where the middle of the string remains stationary, and the two halves move in opposite directions.  This is the first harmonic, and it is an octave up from the fundamental.

And there are even more vibration modes, where there are four, five, six and so on stationary points in the string.  By and large these modes do not sound pleasing.

One more thing.  A string can also vibrate along its length, and that vibration can be picked up.  Usually the sound is horrible, like a violinist’s finger sliding on the string.  When bowing, it is important that the bow remains at right angles to the string to avoid longitudinal resonances.  It is said that violinists take about five years to learn how to use the left hand to get the right notes.  The next five years is learning how to bow properly.

So can piano be a useful guide to loudspeaker bass reproduction?  Absolutely.  I will take four speakers I am familiar with as examples.  The first is the market-leading bookshelf speaker from KEF – the LS50.  Its bass output has a 3-db roll-off at 79-Hz, which is well over an octave above the 31.5-Hz fundamental of a standard piano’s lowest note.  You won’t get much of its first harmonic either!

Staying with KEF but spending maybe eight times as much, we get the slightly bigger bookshelf KEF Reference 1.  Its 3-db bass rolloff is at 45-Hz so you will not get much of the fundamental but the first harmonic should be all there.

My third speaker is a full-range electrostatic from Quad – the ESL-2905. I cannot find its 3db rolloff but it is flat to 45-Hz and 6db down at 31-Hz.  No real need for a subwoofer here.

Finally to a subwoofer – the 18” servo controlled Velodyne DD-18.  This has a 3db rolloff at 14.1-Hz, more than an octave below that fundamental.  Good for a Bosendorfer or Stuart concert grand.

The Velodyne fleshes out the Reference 1 beautifully, and takes a bit of the bass load off the Quad, which otherwise has little need of a sub.

@richardbrand wrote:  "To discover what the first overtone sounds like, move up one octave and play that key.  If the two notes sound as if they are the same frequency, then you cannot hear the lowest fundamental. But my experience on a Kawai upright piano is exactly the opposite, the lowest note is clearly an octave lower and is clearly audible."

I don’t think this is the proof you think it is, and I hope you don’t mind me posting a somewhat counter-intuitive contrary opinion.

Even if we cannot hear the lowest fundamental, those two notes will NOT sound as if they are the same frequency because the interval between the harmonics is TWICE as wide for the key that is one octave higher.  The ear/brain system PERCEIVES the missing fundamental by inferring it from the  interval (or spacing) between the harmonics.  Please Google "missing fundamental", as this perceptual phenomenon is very much in play at the far left-hand end of the piano keyboard.

A few years ago the local Yamaha piano dealer rented our local concert hall, The Kravits Center, in West Palm Beach, for an entire weekend to promote pianos.  A concert pianist was hired to demonstrate and compare the entire range of instruments from the mighty C9 on down.  The most impressive range to me were the upper end of the Clavinova range.  These are electronic instruments voiced to clone the sound of Yamaha C7 and C9 Concert Grands.  The keyboards are dimensioned and weighted to mimic the full sized instruments as well.  Some very accomplished pianists tried them and verified the claim.  I have perfect pitch and in terms of tonality and dynamics at least in the hall going from one to the other, the sound was indistinguishable.  That was on day one.  By day 3, the C7 was going ever so slightly out of tune which gave it away in favor of the Clavinova.  The C9 held firm.

@billstevenson 

I went to a violin / piano recital at the Sydney City recital hall last week, where in the 20 minute interval, a piano tuner came on stage to work on the concert grand piano in full view of those who did not need a beer or a bubbly!  That’s pressure ...

It would be interesting to learn if Yamaha bothers to synthesize the fundamentals for the lowest notes, or just creates the harmonics.  And to learn about the transducers (speakers) they use to produce the sound.  These extra variables are why I suggested doing your own experiment on a genuine mechanical piano.  It is no use listening to recordings through loudspeakers especially if the speakers are in your laptop.

In my sleep last night, I thought of another reason why the piano is an excellent sound reference.  It is because the sound produced from a single key depends only on how quickly the key is pressed, and the piano itself.  The ’touch’ of the pianist is irrelevant because the hammer mechanism is decoupled from the key mechanism.

That is unless the pianist reaches inside and manipulates the strings ...

@billstevenson 

At the risk of stating the bleeding obvious, electronic pianos contain sound systems, with all their faults and idiosyncrasies.  At least some of Yamaha's Clavinova range contain cone drivers and use piano wood for the pulp

Drawing from our experience in building both acoustic pianos and high-end speakers, Yamaha CLP-785/795GP speaker cones use pulp from the same spruce wood used to make acoustic piano sound boards. The result is a more natural, piano-like attack to the sound that is more piano-like when you play the keys.