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I have 1925 Steinway L with sustain issues in octaves 4 5 and 6. I acquired the piano 18 months ago and have become progressively more aware as I have been getting voicing done, and also my playing improving after years of not playing much. The piano had fairly new hammers/ shanks/ rollers, but had clearly not had much use since, and never been voiced

I have read some other posts on the subject of sound board replacement with great interest. The interesting thing is that you need to play the right type of music to bring out the problem, and also that it seems to be somewhat randomly distributed. One note of particular problem is E5. If I tune it down to D#, it's fine, and performs the same as D#! Obviously the board has a resonance issue at that frequency.

The board DOES still have 0.143" crown in the middle (measured from underneath). Downbearing non existent below E4, and between E6 and C7, yet these were not the main problem areas.

I had Restorer look at it, who suggested he could set the frame lower to restore down bearing, but that involves fairly major restoration, and might be a waste of money if the board is tired, and putting more stress on old board might lead to further degradation.

So, I had a thought to use some shims under the strings on the bridge, to restore downbearing. I searched around, but couldn't find any reference to anyone doing that, although I do recall reading a post saying that if the board is already struggling, them putting more force on it might just lead to more degradation.

Anyway, I gave it a try, and it has worked very well. I made the shims by cutting up a (few) feeler gauge (s). I used 0.020" for most, with a few needing 0.026. I am not a technician, but I did restore an upright some years ago for a bit of fun, so I have sufficient experience/aptitude to try it out, and tune back up with help of pano tuner app

At least I have a better sounding instrument while I ponder what to do next, as it is still not perfect. Maybe it needs still more downforce, but I am aware that too much is not good, and also I don't want to overload it, given that it is already tired. A new sound board is a big deal, and not easily done in Australia. One restorer is offering to get a board from Bolduc, but he has never done it before, so I need to shop around for another restorer.

Questions :
1) does anyone know how much crown a new/healthy Steinway L board should have?
2) how much downbearing should a new/ healthy Steinway L board have?
3) Has anybody else tried shims?
4) does anyone have experience with Bolduc boards?

I did go to a piano shop here over the weekend and saw/ played a number of "restored" pianos, including Steinway B, Bechstein A and Ronisch. All had absolutely zip downbearing, and none of them sounded better than my L. The model B in particular was useless above 3rd octave. The asking price of $50k is not bad for model B, and it looks fantastic, but a shadow of what it should be sound wise. I could not understand why someone would waste the time and money to restore it. Who would buy it?? I guess someone with to much money who wants it for "show" and not "go"??

The weight of the treble hammers has a tremendous influence on sustain and projection.

The shape of the V-bar does as well.

The strike point as well.

The condition of the bridge as well.

Soundboard condition is important, but it is less so than the above.

Greetings,
If you have the notion to increase down bearing, I would suggest using the nose bolts. Even though the idea of lowering them .020" doesn't particularly alarm me, I still put a dial indicator on the plate, reading the bridge, when I loosen the first crown nut. If the plate doesn't move, I know that the nose bolt is holding it "up",and I then check the others. If all the nose bolts are under compression, I use the dial indicator to lower them by a measurable (and recordable) amount. If the crown nuts allow the plate to rise when I loosen them, I know that the bolts are already pulling the plate "down", and caution is used before I add more stress. It's prudent to loosen the first one just enough to diagnose the direction, then loosen the others to see if they agree. I have encountered odd situations where one nose bolt was heavily loaded and another nearby was under tension. I suspect someone had blindly lowered something, thus, my tentative approach to moving them without some numbers.

On the subject of plates, in 1975, Bill Garlick described the practices of Mike Glazebrook, at the London Steinway dealership's rebuilding Dept. as being rather cavalier about lowering plates with the strings at tension. I prefer to have a gauge so I know exactly how much rise or fall the plate exhibits before I begin changing anything. I have never broken a plate, (unintentionally), and those I have cracked were much more durable than I initially thought. However, breaking a Steinway plate is a sure way to ruin the entertainment budget for the month, so I don't change their loading, casually.
regards,

Ed,
I don't know why I never thought of putting a dial indicator on the bridge to see where the current loading is. I've always loosened the crown and carefully watched what was going on. I like your method much better.

Concerning the OP, while I believe your soundboard has lost function, loose/poor bridge pinning can cause individual notes to lack sustain. Adding the shims probably affected the bridge pins more than the down bearing.

I see a problem here treating symptoms rather than problems, making assumptions rather than checking facts.

Ed M set out several things that are proven to affect sustain, etc. These all need to be assessed.


I don't care who you are, how smart you are, how many pianos you've "rebuilt" or any of that. It is IMPOSSIBLE to get an accurate assessment of the downbearing situation while the piano is strung. It can't be done. The only person who knows is the person who actually put the piano together and set the bearing. And if that was not VERY recently, forget that too.

You are chasing unrealities if you do not remove all tension and allow the board to acquire its unstressed profile. Then measure your actual DB with the strings out. That is the ONLY to know what you have. Otherwise you're guessing.

I suspect that the actual reason why you think there is improvement since you added shims is due to something entirely different.

Pwg

The root of the problem with the Steinway L that you are having, is the rib scale. Two things, first unlike most other manufacturers, Steinway uses Sugar Pine rib stock, whereas the others use Spruce rib stock. Not a terrible idea as long as it is engineered (which Steinways are not). That introduces the second problem. After the ribs are glued on, they are hand planed to their final dimension, and as you can imagine, that can leave every piano with a different scale, even on the same model. I have attached a simple graph of two actual rib scales (side by side) that shows the weakness I often talk about in the top sections by comparing their Section Modulus. Section Modulus basically tells the designer that the beam is the correct size and thus has the required strength.

I have further demonstrated (in my Chladni videos), that the sand goes up into the top sections of Steinways at the boards fundamental frequency. It doesn't in Baldwins or Mason and Hamlins.

If you are going to replace a board in the future and you want that nice new Steinway sound. Choose either Sitka Spruce or Adirondack Spruce for the panel, and Sugar Pine or Eastern White Pine for the rib stock. And if you want an engineered Steinway L rib scale PM me and i'll provide you with the data.
-chris

I second McMorrow and Pwg’s thoughts. There are other factors which affect sustain and are easier to address.

What type of hammers does it have? If it has Steinway hammers, they probably need a little hardening at the crown.

http://www.overspianos.com.au/

Right there in Melbourne.

Great technician, designer, builder.

Thanks Ed - do you really adjust the nose bolts with strings installed?

Thanks Ed

I repeat I have the same symptom of random notes, across octaves 4 5 and 6. There are a few instance of clusters of 3 or 4 notes, but I also noticed that as I added shims to the more obvious problem ones, I have become more sensitive to detecting others. So, having got the smell of success with a few, I have kept going adding more.

I should also emphasize that I started this little journey trying to validate the suggestion from a restorer to lower the plate. It certainly seems to work, but as per my original posting, not sure if this might be just a band aid that will fail again in a few years.

I have read plenty on this forum about hammer weight. Easy to try, just swap a hammer from higher up the keyboard. Did NOT address my problem.

V-bar has been inspected by 3 technicians who have already worked on my piano. No one had called it out. I wouldn't have thought shim would address that. V-bar looks healthy, no rust. Techs also tried moving the strings on the vbar, in case of contact problem, but no change.

Strike point adjustment available on the right hand cheek block has been adjusted for optimal performance on the last octave. Strike point adjustment by moving the key frame without cheek blocks showed no improvement elsewhere. Please remember I have random problem across 3 octaves. Strike point problem would be clustered at least - as it was with the last octave - which was definitely not optimal in the first instance. BTW last octave has very much higher downbearing, and after technician did some shaping of the hammers, that last octaves rings sweet as. Almost TOO good.

The bridge condition is excellent, and inspected by all three techs who have worked on my piano. No evidence of wonky pins. Soundboard and strings look excellent (and btw pin block is tight as - very good tuning stability).

They are Steinway NY hammers. As per original post, they looked new, and barely had string indentation, so obviously not used much since install (and BTW all three techs commented that new hammer install looks VG). I was surprised to find a hammer the other day with a date of 2002 stamped on it. I had expect them to be no more than perhaps 5 years old.

Anyway tech nr 1 did initial voicing, and boy did he nearly destroy my piano. Absolutely needled them to death. Then I found another Steinway specialist tech (tech nr 2) who has lacquered them back to life, and did as much as he could with voicing to try and address the problem. Obviously the sustain problem is more prevalent when the hammers are voiced brightly (and I prefer the brighter sound of NY Steinway over Hamburg).

"rings sweet as. Almost TOO good"
What on earth does that mean?
Nick

Hi Nick - "Almost TOO good" = a bit disproportionately bright.

Yes, I will. Steinways with crown, low bearing, and weak sound arouse my curiosity. I do it with the dial indicator telling me what is happening, so I am somewhat informed about the stress before I do something. I wouldn't be doing this on an impression made with flat hammers and loose pinning, etc, but when all seems up to snuff except the acoustic response, I go looking beyond hammer shape and strike point.

There is a significant advantage to re-installing the plate and a new pinblock so that the plate can provide the proper bearing pressure at a neutral amount of flex. it leaves a wider margin for lowering or raising bearing after the board is loaded. Plates are actually quite flexible, as anyone that has unbolted an older Steinway plate from the case and seen how much it rises at the tail knows. I have also seen soundboards that didn't "fall" evenly under string tension, with sections that had good bearing when un-strung approaching flat under tension, and flat sections not moving at all, etc. An older piano guy, years ago, held that plates need to be flexed to some degree, to maintain the entrainment of the string vibrations. It is a rare Steinway plate that just lays there on its contact points when the strings are off and the rim bolts are loosened. I have measured almost 1/2" rise at the tail of the plate when it was still attached to the pinblock! Either they warp after the build, or the builders bend them into place during the initial fitting..

When the piano is strung and in tune, sustain and power considerations can be made aurally as the plate is moved up or down .020" or so. (Be mindful that dropping the plate and strings will push the soundboard down some , so using the board to index the indicator means the plate may actually drop more than indicated because it is chasing the soundboard as it goes down. In some situations, the piano's voice was noticeably improved, but not always. I have pounded on unloaded boards like drums, and then listened to the strung piano, and cannot make a correlation of a "booming" board and a big sound. I can think of several outstanding pianos whose boards were unremarkable while in the shop being thumped. And a Chickering I had sounded like a bass drum, yet when strung, had little sustain, even after monkeying with the bearing.
Regards,

Here is a link to some audio recordings I prepared (with a little cut and paste using audacity). Each audio file has 4 repeats of before and after shim (the first note played is without shim, then with shim, then without shim again, etc).

Before and after shim recordings

As is often the case, hard to capture in a recording - the improvement is certainly more dramatic live. The D6 recording is perhaps the most obvious to my ear at least. When I listen to these recordings myself, the sustain does not appear to be that noticeably different, but the attack is strong/dissonant, which perhaps makes the sustain appear less.

In comparison to pianos I tried at local shop on the weekend, with NO downbearing at all across the whole bridge - especially notable Steinway B - these pianos did NOT display the strong/dissonant attack I am experiencing on my L, but rather just very weak non resonant sound.

Also some photos of the bridge.

Steinway L 1925 Bridge photos

Ed F. said:
"I have pounded on unloaded boards like drums, and then listened to the strung piano, and cannot make a correlation of a "booming" board and a big sound. I can think of several outstanding pianos whose boards were unremarkable while in the shop being thumped. And a Chickering I had sounded like a bass drum, yet when strung, had little sustain, even after monkeying with the bearing.
Regards, "


There is a little bit of false conclusions here that I would like to address. Ed F. is basically comparing apples to oranges. In this case, it would be mass and stiffness.
The first scenario described would be the relationship of the mass in the board to the rim. Adding the plate adds enough mass to the system to allow the focus of energy back into the board. This can only be fixed by reducing the mass in the new board. But what happens too often is the old board just gets copied.

The next scenario described is the Chickering. The deep bass tone of the fundamental frequency, if too low can indicate the enough loss of compression ( even if there is still crown). This could mean that setting downbearing, no matter how lightly could overload the board. This could be particulary true with Chickerings as often their rib scales are poorly designed.
-chris

Thanks Ed - that approach does makes sense to me. It is certainly a common practice to re-cap a bridge, which I guess is at least partly directed towards restoring downbearing (as well as fixing bridge pins).

I assume you do all four crown bolts, or do you focus mainly on the two in proximity to the treble bridge - which is the primary problem area?

What is the longer term prognosis for this approach - or for that matter any approach which applies more pressure on an old sound board. Can we expect the old sound board to handle renewed pressure for at least (say?) another 20 years? I am certainly not happy with how it is (or at least how it was without shims), so I am not precious about preserving something that is not what it should be.

sorry - I incorrectly wrote above "... all four crown bolts", instead of ".....all 4 nose bolts" - or are the two on the left most side of the frame called something else?

I'm only going to give this warning once more:

You are "playing with fire" if you start messing with nosebolts to address this issue.

1) You do not KNOW "where" the plate is right now.

2) You do not KNOW what the actual DB situation is...you are guessing.

3) You are ASSUMING that any change you realized by shimming under the strings is due to increased DB on those notes.

4) You have increased the stress on the bridge pins laterally significantly. This is not good.

5) You are contemplating doing an operation that has the potential for catastrophic consequences and you are doing it with advice off the internet from people you don't know and that have never seen this instrument.

I am frankly surprised that you are being advised in this way and I do not want any part of it. I hope it works out for you.

Pwg