Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Yamaha U3H: add felts to unused string lengths?

Sorry for the use of incorrect technical terminology. What I mean is the part of the strings close to the support pivots. I have seen mostly in Grands that there are felt strips interlaced with strings to prevent those unused string lengths to resonate.

On my U3H there are not such felts and I wonder if they could be added to reduce somewhat the brightness of the sound. I am mostly happy with its sound but of course if there is any resonance on those strings, it may be undesirable, right?

Thanks for any hint!

Probably having a competent technician (not just a tune-and-run person) voice the piano would be most likely to provide the results you are looking for.

The piano was manufactured according to a design and apparently the designers felt the understring felts were not necessary. Putting felt or stringing braid in "might" have some small effect but I wouldn't expect much.

Beyond that, there are options to use acoustic foam to reduce sound output.

Thanks, now I know they are called "understring felts". Well, I thought of it yesterday, as the damper pedal did some noise and I opened the low cover to put some graphite on the pivot point. So, while inspecting the arp and the nice construction of the piano, I played some keys and carefully touched the understrings to find some of them resonated with some notes. The sound of the U3H is nice, on the bright side, but not too harsh. It was just a thought, I will probably try it anyway, as there is not much to lose

Are we talking about up between the tuning pins and the speaking lengths? Just behind the counterbearing?

If so, and there is no understring felt and no stringing cloth of any sort, and you have three segments of wire all different lengths vibrating freely (if this is what we're talking about), then muting these will in fact change the sound of the piano possibly significantly. I have found this to be an annoying problem on Kawai K series uprights. It is a background zinging ringing sound that ought to be muted.

If this is not what we're talking about here, then disregard my comment.

Peter Grey Piano Doctor

Yes, that is what I was referring to. So I could be right and muting them could get rid of unwanted resonances?. That is a good thing to test then!

On a further note, how would you mute those areas?. Is there any picture you could link of the correct way to use stringing cloth on an upright?. Thanks!

No wait a minute EB5AGV. I think you are talking about the BOTTOM end of the strings in this Yamaha U3, because you talk about taking off what's properly called the bottom door or kneeboard, to lubricate the pedal mechanism.

So I think you are talking about the length of string between the bridge, and the hitch pin below. Yes? By what you call "support pivots", I think you mean hitch pins - where the bass strings are secured on with loops, and the plain wire strings loop round them and go back up again for the next string. Yes?

The felt or thin braided cloth that weaves between the strings here, is sometimes called "stringing braid". "Understring felt" is at the top of the piano near the tuning pins (in a grand piano at the keyboard end, near the player).

I would not feel inclined to mess about with stringing braid in a U3 that hasn't got it. They are well designed and well made pianos. Better, I think, to talk to your regular technician about voicing.

Hi David,

Thanks for your comment. And sorry for using the wrong words to describe the piano parts. I will try to learn for next time!. Yes, you describe exactly the string area I checked. I was also going to check on the upper side but, of course, for sure YAMAHA knows better than myself... I am an engineer, but in Telecommunicaton. I enjoy working on mechanics though and when I got my U3H in February 2020, soon I noticed that there was a problem with most of the keys, as the escape mechanism didn't work as expected and sometimes it prevented the keys to work. I studied the mechanism and found that the capstan needed regulation, lowering them, so the jack could work as expected (it didn't return to its resting place sometimes). It was a curious thing as the adjustment was off very uniformly. I read a lot on that subject and watched several videos before doing the adjustments. And, well, I got it working as it should. I guess the change in temperature and mostly in humidity from the studio where the piano was, to my home, had modified the adjustment.

All in all, my point here is that my mind is used to look for solutions to problems. So, as I am not sure which part of the metallic sound of my U3H is just as it should be and what is perhaps due to other causes, I found curious that the strings seemed to resonate even on the length between the bridge and the hitch pins.

I think one of the problems for me is that I am too used to VSTs and the real thing has quite a lot more of subtleties which could be mistaken by problems by my untrained ear.

So, well, I guess the best is to leave the U3H as is and figure out, by listening to other pianos (it is not easy nowadays), if my unit needs voicing.

Thanks you all and sorry for the rambling!

I never felt the need to mute those strings on my U3 (although my current K800 come with them already muted off)but, really, it is cheap quick and non-destructive to mute those strings so why not try it and see if you prefer the tone that way? The U3 designer may have thought doing so was not an improvement but that doesn't mean your ears might not disagree. Even if the metallic sound you dislike originates somewhere else you may still prefer the strings muted, or not, but in that case the muting is easy to remove.

I even have already the felts to do it ...

Next weekend I will decide what to do

Don't worry about not knowing the 'right' names for parts! There are quite a few differences for names of parts between USA and English piano nomenclature. Though the UK, not having any piano factories left, probably doesn't have any right to insist on names!

You will learn names of things as you go along, I am sure.

Being Spanish doesn't help either!

You've made me realise - I don't think Spain ever had a piano industry, did it?

Yes, years ago there were plenty of small manufacturers in Spain. In fact, you can buy pianos of that era for peanuts, even some times get them for free. I think the latest vanished on 1960s as imports began to be easier.

I have found some interesting information:

Spanish piano manufacturers

Looking for images of U3 pianos I see that some have the stringing braid and some do not. I wonder if it's a matter of destination region? Anyway it certainly can't hurt to put the braiding on there and see if it helps. My guess is it will solve your issue.

Please, could you link to one of those images with stringing braid?. Thanks!