Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Dull and thuddy tenor hammers

I have a tall upright with new Abel hammers on. The piano sounds good except in the low tenor (last 6 strings or so, C3-F3) steel wire area just before the cross over into the bass.

The hammers have had some needling to the cushion area. The strings when plucked sound quiet good.

Sound advise will be much appreciated.

Thank you.

Are you sure it's not the strings? I've got two pianos (110 years old and 170 years old) both with some steel wound strings in the tenor. They sound awful. The copper wound that carry on down are fine. Maybe your answer will be my answer.

Well, the last plain wires have usually the lowest tension of all, and it creates an impedance problem with its SB area, because is on the corner side and too stiff... Strong needling their cushing hammers will mitigate that "muak" sound but they'll sound too dull and the break with the powerful copper bass ones (with are very much tensioned and located usually more centred on the SB) will be more accentuated. As always the most conflictive part in any piano...
All the best,
Lluís

This formula works for me:
Check the sound for all dynamic levels. If it is tubby at piano but has good power and tone at forte, I would harden the hammer felt slightly near the strike point. If tubby at piano and forte with poor power or tone, I would strengthen the shoulders of the hammer. Then possibly near the strike point as needed.
Use a lacquer or keytop solution that is thin and can penetrate deep in the shoulders if you go there.
I like keytop - especially on the strike point area because it is partly reversable.
Also, before you put chemicals on the strike point you can try ironing the felt carefully.
You will need to experiment.

I use ground plexiglass in acetone for the dope mixture. I like the more subtle way it works compared to other materials. Its much harder to over do it with the plexiglass and you can always put another dose on if its not enough. Ari Isaac uses the same mix on his incredibly nice hamers when he voices.

As Has been said, be absurdly (my spellchecker did that. I meant absolutely but absurdly is just as good) -certain it is not the strings. Have you seated the termination points, all of them? Even the ones not in the speaking length including the hitch pin amd tuning pin coils. Sometimes, even on a good piano, a little dullness develops on some notes in that region. I just seat the tuning pin coils to clear it up immediately without disturbing a good tuning. Your problem may not be so simple.

When you pluck the strings the sound should be brighter than the sound you'd expect from being played with the hammer. Pluck a string on the last good sounding note and compare it to its neighbour, the first bad sounding note. difference??? Listen closely. Closely. You can switch hammers on those notes temporarily to compare.

There are many safe things to do before resorting to chemicals, an act you might regret when you find the true cause. Even acetone has a drying time that is deceptive. If you are only going to see the piano for an hour or two, think twice. The result after half an hour is different from the result the next day.

Yes, I'm talking of fine work. What do you aspire to? If you can't hear the difference between a hammer problem and a stringing problem you haven't the experience to use chemical hardeners.

Fit hammers to strings, ironing, first cold burnishing then hot if necessary. Is the hammer an appropriate shape? A single needle from the back of the hammer parallel to the moulding about 3/8" from moulding going in about an inch will bring the yone up Tapping down the felt on the strike surface. Do the non invasives first and you will get a better sense of what is in the stringing and what is in the hammer. Action regulated?, hammer travelled? Any two or three of these operations could make a bad note into the best note on the piano.

If the problem is in the strings, putting hardeners in the hammer will compound the problem.

In all piano work, don't create difficulties or problems for the next tuner. The next tuner might be you.

I also have a tall (54"), upright 1956 English made" Brock", I believe he originated from Holland.
I also have the tubby sound, but mine comes from the first three pairs of wound copper bichords at the begining of the base bridge. All the strings on the long treble-tenor bridge are plain steel and have much more power than those on the base bridge.
I have bought one pair of Ari Isaac strings and there is a marked difference so I'll probably buy at least two more pairs.
I did once find a post by Del Fandrich where he suggests adding some weight to the end of the base bride; I presume this might also apply to the end of the tennor.
I also presume one would fit said weight onto the bridge by using, at the back of the sound board, one of screws which secure the bridge to the sound board.

The weigh will mostly buy you some sustain and lower the explosive character of the attack. I did not find them doing anything on the spectra, just an enveloppe change for the longer, less open too, slope.

Hammers can help to some point if you can obtain a similar attack and dwell on both sides , feeling the energy of the strings in the keys is usually not difficult in that portion of the scale. (similar tinkling in the fingers at mf with a totally decontracted finger once the note have spoken)

Then regulate the spectra without loising too much energy.

Check the shank tone as well, a bad shank may kill a note easily

Btw it is normal to have bad basses on a 1956 piano. If worth all the basses can be changed.

As Lluis has said, that area is where the percentage of breaking point (PBP) is usually the lowest, often below 30%. This leads to inharmonicity problems, tubby-ness, poor tone, and a pronounced tonal break going down into the bass section. When this is the case, messing with the hammers merely amounts to trying to mask the situation - it does not affect the root cause.

I would check the tension on those unisons using scaling software (shareware is fine). Much has been written on this site about how to improve the tenor break. I advocate restringing the lowest plain wire unisons using a softer wire with a lower breaking strength, such as Pure Sound. At pitch, the strings' PBP will be in a more reasonable zone. This can mitigate the tonal problems in a fairly non-invasive, easily reversible way.

Have you checked to see that all three strings are phased together by the hammer strike? Have you checked the pinning of the hammer flange? Even a jack that is loose on one side will bias the hammer motion askew on a forte blow. Is the spacing such that the hammer is tipped significantly to the side so that forte blows make the hammer wobble or deflect enough to destroy unison phasing?

Yes Ed for your last sentence... too much shank flex and the tone will never be clear at that place.

Thanks to all for your replies.

I am away now for the next two weeks, so i will only be able to run through the piano when i get back.

The piano is a circa 1902, Schiedmayer and Soehne upright. It has a brass flange rail. From what i recall the center pinning is fine. Strings are level, hammers mated, strings tapped onto bridge. I think it may be a SB issue down in the low tenor.

Once again, many thanks for all the input.

Mark, your last post sparked my interest. Brass flange rails are very uncommon in German pianos. When you get the chance, would you mind taking some pictures and either posting them or sending them to me off-list?

I would look very closely at the bridge.

Good thought.

A bridge separating from the soundboard would present itself as quieter notes.

Problem splitting would be noisy.

Sometimes the end it the long bridge touches the plate. It's been a long time but I think i remember the presenting symptoms included dull notes with reduced sustain.

It is not uncommon for the tension on those notes to drop off dramatically. This is part of the design. Raising the tension by using thicker strings will help somewhat, but it also may be desirable to lower the tension on some of the higher strings to even things out. Low tension causes a drop in volume and a sort of boomy sound.