Why not the piano as a reference for bass

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

@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. 

@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. 

@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.

@mahgister wrote: "Could you please name one or two even three albums of piano very well recorded...i want to buy them...

"It is very important because as you i think piano sound is a judge in my system/room..."

You might consider "Red Descending" by solo artist Seth Kaufman.

Seth was a medical student in New Orleans when I first heard him play at a Barnes & Noble. He blew me away so I bought his album, "Circling Noon".   When his new (at the time) album came out, "Red Descending", I bought it because I was already enjoying "Circling Noon" immensely.  Loved it, still do.

Then I got a chance to hear him live again in a real venue, and the Yamaha grand piano he was playing sounded to me just like the one on "Red Descending"  (I had been listening to the album over Sound Lab electrostats).  After the performance I asked him about it, and he said YES, it WAS the same piano!  He'd gone to the trouble and expense of having his piano crated and trucked from New Orleans to the recording studio in Los Angeles for recording the album.

Not that I am any expert on piano recordings, but apparently "Red Descending" is a good enough recording that a non-piano-player could tell with pretty high confidence when he heard that same piano again. 

Duke

@mahgister , I particularly like "Repercussion". At one point about halfway through Seth stands up and leans forward and plucks the strings with his fingers.  I didn’t realize that’s what was going on until I saw him perform it live.  It had never occurred to me that plucking the strings of a piano is a thing. 

Aside from that, "Repercussion" gives me chills every time I listen to it. 

https://www.youtube.com/watch?v=nMI_SsJN6Zg

(In case it's not obvious, yes I absolutely use solo piano music for evaluating speakers and for showing them off... but I'm showing off "see, that sounds like a real piano" instead of "listen to that amazing bass".)

Duke

Thank you, @mahgister!  Very glad to hear Seth Kaufman's music speaks to you too!