Relative Humidity and Piano Tone

Seeker

After a winter that was so cold with so much heat running into my studio and my single Venta humidifier not quite keeping up (I posted something about getting a 2nd and asking a questions about humidistats in the technicians forum here just now), the humidity is regularly no less than 39% and is usually about 45%. Aside from raising the pitch a few cents, what I have noticed is that both of my pianos SOUND better - it's subtle, but the sound is warmer, more open. It was very good before; now it's even better.

Wonder if any of you have noticed this too?

It makes sense to me that this occurs. My string player friends have humidifier inserts for their instruments and hygrometers in the instrument cases. The wood is kept more open, and the sound with it. Why would this NOT be the case with pianos?

I think this can make a discernible difference. It might also be relevant when people buy an instrument that sounded great at the selling venue, but not so great at home. Perhaps relative humidity is something to be checked on both ends of that situation. If the shop is managing theirs well at close to 50%, and your house in the winter is at 28%, I suspect the piano will sound more nasal and closed than it did at the shop - maybe more brittle. Can't say for sure, but wonder if that's probable.

Your thoughts? Observations?

Gombessa

What you say makes a lot of sense, Seeker.

From your description of your winter conditions, I'd suggest that is the ideal RH to keep your piano at - mid 40%s. I have a whole-room dehumidifier and I keep it between 45-47% RH 24/7, 365. What's MUCH more important than that however, is how consistent you can keep it throughout the seasons. I think a piano consistently kept at 60% year round has as much chance of being in better shape than one that bounces from 40-50% through the seasons. But these are things we only have a limited amount of control over, in the end.

Since the humidity affects the rim, the soundboard, the legs, the keyed, action, key sticks, glues, and felts, I think it definitely has an impact on the sound. My thinking is that the most immediately noticeable thing though, is the feel of the action, especially if it gets sluggish or sticky, so that's what people will focus on. But as you described, your piano sounding better at mid-40% RH kind of jives with that being the ideal maintenance humidity for the instrument.

BartK

Oh yes. It does make a difference. For a while I wasn't very careful about monitoring the humidity and it got to a stage where it was chronically too dry (about 30%). The result was that I started noticing some strange ringing sound that I couldn't quite locate. It turned out one of the brackets that holds the lid when it's closed had some loose screws and it resonated when the piano was played. My tuner located it and told me that the low humidity can cause things to go loose like that.

Gombessa I think a piano consistently kept at 60% year round has as much chance of being in better shape than one that bounces from 40-50% through the seasons. But these are things we only have a limited amount of control over, in the end.

Well, ideally yes, but I don't have lab-grade equipment to precicely control the air quality. I have to open the window to let fresh air in sometimes and that inevitably leads to some fluctuations. Usually, much more than 10%.

Seeker

Gombessa Well, I think I've got a solution that while not quite optimal, is going to okay. I found a green house humidistat on Amazon. For some reason, the URL will not display here, but if you're interested search for Inkbird IHC200 humidistat. I tested it with one of the Ventas, and it works perfectly. I've set it to keep 44% as the desired RH with a tolerance of 2.5% below that before supplying power to the Venta. Worked perfectly. So I'm going to get another (humidistat).

I think, that unless we have more of that 5 degree F weather, the 2 humidifiers can handle keeping the humidity within 2.5% of 44%, and that will suffice for all but the most humid of the summer season. It gets VERY HOT and VERY HUMID here in the DC suburbs, and last year, I know there were days when the RH hit 60% despite my having a high end Daikon minisplit that keeps the temperature +/- 3 degrees F year round. So... yes, the pianos will get more humid in the summer, but they both have Damp Chaser Bars on them, and at least the board on the grand will be around 45%, and the Konzert8, being an upright, will have the board AND parts of the mechanism around 45%. So... I think that is going to be good enough. It's going to have to be, because I'm not going to add a dehumidifier on top of all the other machinery I'm tending in the studio. I barely have room for everything in there as it is, and I don't know where I'd put it, and it would certainly, unlike the mini-split, be noisy. So... that's the deal for me.

As for little sounds that disappear with distance, yes, indeed, that is true. The problem for me comes when making my recordings. Right now one of my favorite spots for my microphone is behind and above my head, so the mic essentially here's what I do. Moving it to the speaking side of the instrument, and back a few feet is a possibility that I may try, but for the most part I find the first position best.

Gombessa

BartK Well, ideally yes, but I don't have lab-grade equipment to precicely control the air quality. I have to open the window to let fresh air in sometimes and that inevitably leads to some fluctuations. Usually, much more than 10%.

Yep. There are things we can do (whole-house, room, at-the-piano) and then there's real-life. My family prefers to keep the window open a few hours a day to let fresh air in. I'm not going to prohibit that for the sake of an instrument sitting in the room, even if I do end up staring at a monitoring setup just a little bit and lamenting the RH going up 20% in the course of an hour 🤣

Edit: This thread prompted me to check my monitor, and lo and behold, my oldest wireless piano hygrometer finally ran out of batteries. Looks like it's been offline for 6 days. I installed it August 6, 2022, so wow, I'm super impressed. One set of batteries and it lasted over 2.5 years, transmitting temp/RH 24/7!

ShiroKuro

@Seeker I definitely notice that my piano sounds better when the humidity is between 35% and 40% and it sounds noticeably worse when the RH reading is 30%. I think it impacts the hammers (as I wrote in a different thread here not long ago)

One other thing that's relevant is that if the piano is tuned when the room is at 40% RH, then it will sound better at the RH. ...

brdwyguy

Interesting, agree Shiro, my piano just hit 42% for the 1st time this season (Winter)
and this is with a Venta Room Humidifier ( Opinion: way over priced for a piece of plastic that doesn't work very well )

Anyway, I just called my tech who is the Dampp Chaser Rep for our area and ordered one - I'm tired of filling the Venta Humidifier every 12-24hrs or so. It will be installed next Tues, can't wait.
I realize the Damp Chaser needs filling but I doubt it will be as often.

Suggestion/Opinion: Don't spend the money for the Venta, just get the Damp Chaser System for your piano, ESPECIALLY if you have a High-End Grand!
Done!
brdwyguy

pseudonym58

You can really go overboard with this stuff. It's obvious that you have to keep the room within certain parameters to avoid eventual damage to the instrument. Other than that, when you consider the kind of materials that a piano is made of, it's going to vary slightly every day, having to do with relative humidity, barometric pressure, temperature, etc.
I recently read a book where the author became totally obsessed with the sound of her piano in her home, having half a dozen technicians replace the hammers, do all sorts of other work, in a desperate effort to recreate whatever it was that she felt she originally heard in the shop where she purchased the instrument. It was painful to read as it was obvious that she was torturing herself.
I've sat down to play the piano at times where I've wondered "Is this really the piano I chose for myself?"
But the next day it's fine, or whatever problem or unevenness was irritating me is greatly diminished or not present at all.
I think a person that can't accept the fact that a piano is going to vary somewhat due to complex interaction of environmental factors is probably better off with a high-end digital piano.
My technician has indicated that 9 times out of 10, a perceived twang or sharpness to a note is the slightest imperceptible shifting of a unison. He demonstrated that for me once by fixing a sharp sounding note by means of correcting a seemingly good unison.
Silliest of all, perhaps, is the situation that happened to me once: a certain note in the treble range to me had a more prominent-sounding key action-linkage, a slight thud where something was out of whack. My wife never heard the difference between that note and the notes around it, so I decided to stand up while I was playing the keyboard. Just that extra 2 ft eliminated the thud. Now I routinely just ignore it as if it's not there.

pianoloverus

pseudonym58 I recently read a book where the author became totally obsessed with the sound of her piano in her home, having half a dozen technicians replace the hammers, do all sorts of other work, in a desperate effort to recreate whatever it was that she felt she originally heard in the shop where she purchased the instrument. It was painful to read as it was obvious that she was torturing herself.

If the book you're referring to is Grand Obsession, then the problem was that the tech who originally tuned the piano for the showroom from which it was purchased used a special tuning he called a Schubert tuning. Unfortunately he didn't pass that information along to the buyer so that when she had it tuned the normal way by other tuners it sounded different. The problem was solved when this was discovered.

pseudonym58

Ron Koval wrote on Piano World in 2014:

"Like any of the differing stretch approaches to setting equal temperament on a piano, the effect can vary based on the listener. To most, there won't be any difference heard, or it may be a very subtle change. To the author of the book, the effect the tuning had on her was enough to go looking for again; to find the tech that had been doing the tuning for the piano store...

An aural tech can approximate the result by just favoring 4ths over 5ths when setting the temperament - and then expanding out favoring double octaves over single octaves."

Elsewhere, I read that another name for that particular tuning is "well temperament".