Does the timbre change when you push the pedal down?

dore_m

I have my opinions, and I've seen other discussions about this.

If you play a note on an acoustic, hold the note, and then push the pedal down - does the timbre change?

Del Vento

dore_m If you play a note on an acoustic, hold the note, and then push the pedal down - does the timbre change?

I assume by "pedal" here you mean sustain, but just in case you meant sostenuto or una corda, my answer is "definitely not", because nothing that could have changed the timbre is happening. It equally won't change if the piano has a "soft" pedal (typically on an upright), either by moving the hammers closer to the strings or by putting a piece of felt between the strings and the hammer (actually the latter might marginally change the timbre by selectively screen some frequencies, but we're spitting hair with that).

Now, with that out of the way, if you do mean sustain as I believe you do, the question is what do you mean by timbre? I can definitely hear string resonances if I push the pedal down without any note playing (the "famous slushhhhh"). If I do the same while a note is playing, I can definitely hear the resonances, and hear them stop if I raise the pedal, and start again if I push it again. I've just tried it right now on my grand. I am not sure I'd call that "timbre" though. It's more like "ambience".

And finally, to state the obvious, if the pedal is lowered before the note is struck, the effect is much, much larger. That I can definitely call "timbre". I believe this is due to the much higher harmonic content during the attack which can excite a lot more of the other strings than the sustain can if I lower the pedal at a later time.

CyberGene

If you press the pedal shortly after you played the note, there will be enough energy in the vibrating string(s) to still excite the open strings, so you can hear some damper resonance. That was one of the tests in the DPBSD suite of tests made by Dewster on PW.

dore_m

CyberGene That was one of the tests in the DPBSD suite of tests made by Dewster on PW.

I didn't know about that one. But it looks like I'd have to sort thru 150 pages of posts myself to find that part, unless you know where it is. I was just going to test myself and run a spectral analysis - I've done something like this already with prelim results. But still want other opinions about what their perceptions are.

dore_m

So I made the argument on another forum that the energy that is caused by the impulse can cause the other strings to resonate if the pedal is already down - but if the pedal goes down after the strike, there isn't enough energy to meaningfully resonate the other strings. To test, I recorded a note then pedal down after about 500msec. Spectral analysis didn't show frequencies changing, just the noise floor increasing, exactly like if I separately recorded a pedal up sample and then mixed in the "hsssh" of the dampers going up. If we define timbre as the mix of frequencies/harmonics and their peaks, I didn't see any change.

CyberGene If you press the pedal shortly after you played the note, there will be enough energy in the vibrating string(s) to still excite the open strings, so you can hear some damper resonance.

Now, perhaps I didn't push the pedal down fast enough, and the energy dissipated quickly. I'll have to try it. Granted, I need to tune my piano, and the tuning would affect the effective energy transmission, I'd guess. However, I would also think I should see SOMETHING in the spectral analysis. I'll have to try and see.

Any predictions?

SouthPark

Del Vento (the "famous slushhhhh")

Now I know what many people mean about the slushhhh / wooshhh / shhhhhhh! In the past - I had seen people attempt to describe that, and I didn't make the connection because my interpretation of it is like a rumble or subtle growl.

https://www.youtube.com/watch?v=JK2KGTygynU

dore_m

I did mean the sustain pedal, and I purposely wrote a little ambiguously so that others could interpret in the way they wish. I want to see if there is general agreement in interpretation and answer.

Del Vento

dore_m I did mean the sustain pedal, and I purposely wrote a little ambiguously so that others could interpret in the way they wish. I want to see if there is general agreement in interpretation and answer.

Sounds good. Hope my contribution helps. If you need follow ups on what I said, let me know

MacMacMac

dore_m I didn't know about that one. But it looks like I'd have to sort thru 150 pages of posts myself to find that part, unless you know where it is. I was just going to test myself and run a spectral analysis - I've done something like this already with prelim results. But still want other opinions about what their perceptions are.

It's here:

https://forum.pianoworld.com/ubbthreads.php/ubb/printthread/Board/6/main/98840/type/thread

vagfilm

My 2 cents... By "note timbre" it must assumed a spectral signature that is specific to that note. As @Del Vento said, if the pedal is pressed while the note is held, you are adding a piano-wide effect of freeing the strings on top of the played note. If you can somehow Fourier decompose/separate these two sources from the overall spectrum, my bet is that this second component would be exactly the same for any played note. Thus, since it is not note specific, it may be argued that the "piano" timbre may change, but there will be no change in the "note" timbre.

dore_m

All very interesting answers, and pretty much in agreement....

Khuja Wangtishvili

Yes of course. Every 6 year old who ever played the piano knows it.

dore_m

Khuja Wangtishvili Every 6 year old who ever played the piano knows it.

You just insulted my 13 year old who has been playing since 6. I doubt a 6 year old could express this.

And there are plenty of people who disagree over on that other forum.

SouthPark

Pushing the sustain pedal gets into that string resonance territory, right? The 'undampened' strings getting some energy into them - potentially excited by whatever acoustic energy is hanging around.

vagfilm

SouthPark potentially excited by whatever acoustic energy is hanging around.

Absolutely no experience with acoustics (so take my comments with a very large pinch of salt) but I truly doubt that a single decaying note past the hammer attack retains enough energy to excite newly undampened strings. I bet money that the "slussshhh" of releasing all 88 strings (or sets of strings) is the same as releasing 87 strings plus one held and decaying (well, maybe A0 after FFF strike has some effect 😀...). The mechanical disturbance of the string caused by lifting the damper is probably larger than whatever sympathetic effect may be transduced by the bridge or soundboard... You need free but resting strings for optimal sympathetic resonance.

dore_m

So mostly I hear "no" to my original question, with descriptions about why. I'm waiting for a "yes" with a description.

SouthPark

vagfilm Excellent points you make. The string resonance condition …..with the extra spectral content occuring after one or more notes is struck and held with their keys remaining depressed, followed by pushing down the sustain pedal …… is an effect I assumed happens, based on the discussions out there. Although, the exact interactions, degree of interaction ….. and how loud etc one or more notes need to be, taking into account geometry and surrounding environment, string diameter/weight etc ….. that's probably a hard one.

SouthPark

It probably depends on perspective or point of view. If the individual note sound with one key depressed (prior to sustain pedal pressing) creates one sort of sound, and then pushing the sustain pedal (with key still pushed with finger) leads to a noticeable change in sound due to a set of open strings resonance, then the 'notes' timbre could be considered to change.

A matter of perspective.

vagfilm

... But that perspective would lead to say that the timbre of any note changes when you play a second note... Does is it make sense?

SouthPark

vagfilm Yes ….true. If a second note is played, then one approach is to consider playing that second note by itself. Not both notes at the same time.

With both notes at the same time …. and interaction among themselves and with other strings, then that moves toward the piano timbre situation you mentioned ….. that's if linearity/superposition doesn't hold up … and probably doesn't.

dore_m

MacMacMac It's here:

I did find the thread. What I was referring to is the exact place in the thread that describes the phenomenon. It's 150 pages to sort thru, and I'm really looking for proof of the timbre changing, not just a description, although a description would be nice.

MacMacMac

dore_m I did find the thread. What I was referring to is the exact place in the thread that describes the phenomenon. It's 150 pages to sort thru, and I'm really looking for proof of the timbre changing, not just a description, although a description would be nice.

I saved the entire thread as a Word document. Actually three Word docs.

They'd be easy to search … much easier than scrolling through a vast batch of web pages.

If you want them let me know.

SouthPark

If they just have a nice mic system setup, then recordings on various acoustic pianos will likely answer that real quick. That's probably what they did already. As in play the key firmly …. hold it, and keep the key (single note only) held with the finger and don't let go, then after a few seconds … push the sustain pedal with foot for 3 seconds, and then remove foot from sustain pedal. Then stop recording. Then analyse spectral content versus time.

dore_m

SouthPark If they just have a nice mic system setup

Simple for me to do. That's why I'm asking for opinions first. I can publish my findings here, but I wanted some predictions.