Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum hollow phantom tone at the bass break

I'm not hearing the phantom tone. The most distracting thing to my ears is the out-of-tune unisons. Second is some strong harmonics. Could you be hearing an upper harmonic as the phantom tone? (Like when you play B2, what pitch is the phantom tone? F#4 would be telling.)

Not a tech, but what I hear on B and the notes above is different from what I hear on the notes below it. The B and C sound really strange to me.

IMO it would be beneficial if you post another video with playing each note longer and and a couple of times. Also this time you might also mute and play single strings so that out of tune unisons get out of the discussion. Just an idea.

Ed McMorrow - The customer complains about it not sounding right. Oddly enough she cannot hear the phantom tone but knows something isn't right.

Gene Nelson - I tried thumping the underside of the key bed in several places but got nothing. A couple months after this originally happened I could make the phantom sound change a little by applying pressure with a screw driver on the bridge next to the bridge pins of the affected strings. I could not find anything loose or unglued but thought I would try a screw at end of the bridge. That had no affect so I put a small diameter bolt and nut through the bridge and sound board to rule out any possibility of something loose but it had no affect. I left the bolt in it. I took a picture of it but have not been able to attach it. The you tube posting apparently is for videos only.

I was hoping the suggestion would give a clue as to the origin of the sound your hearing and would be somewhat similar to the noise I hear on the audio you posted - it still sounds like key bed related noise as opposed to soundboard related. Sometimes a softer front rail punching can help.

There is no backscale on a Yamaha GA1
Ian

To Gene N. - I tried thumping several differrent places on the bottom side of the key bed but got nothing.

Some months back I had tried compressing the bridge end with a screw but got nothing so I then put a small diameter bolt clear through with a nut just to rule out any issues. The bridge and bridge cap were not loose but I could make the tone different by applying pressure at the bridge end with a screw driver and since I couldn't find anything else wrong I gave it a shot just in case. This is a link to a picture of the bridge end
http://s000.tinyupload.com/index.php?file_id=86604267638082851317

To Ed M. - Yes the customer is complaining but oddly enough the customer doesn't hear the phantom tone she just knows it doesn't sound right.

What I hear is that the hamer(s) are not faced square to the strings I have the same problem on my 53" upright at more or less the same position. I may resort to buying and fitting new base hammers of the type which have sides cut so that they align at the same angle as the over-strung strings.

This is a test. For some reason my last two posts over the last two weeks do not appear in this thread.

I can see them now. I will try making another video after the New Year. Thanks everyone. Merry Christmas & Happy New Year.

When you pressed on the bridge end you added impedance to the bridge end. Go under the piano and see if the beams will allow you to roll up and insert a sock or springy rag to press up on the bridge end from below. This is a way to voice down the "boom" at the end of a tenor bridge.
This is a short-scaled piano, and the low plainwire notes suffer the most. It is a design flaw which, once you hear it, you can't quite overlook it.
Also explore needling down the hammers of these low plainwire notes. (First test with the una corda to see if that helps.)
It is possible to replace the low tenor notes with wound strings, which may help smooth the transition across the break and make a better inharmonicity curve.

Definitely the back scale !

It has taken longer to get back to this than I had anticipated.
I tried applying some upward pressure on the sound board just under the bridge end with the heel of my hand since it was in an open space. I could change the phantom tone a little but it didn't help it any.
I have tried all of the suggestions listed so far but nothing has caused the tone to go away. I have made another video of the phantom sound, but it doesn't come out as strong in the video as it does in real life, this is the link https://youtu.be/OPhmuRAZQX4
Any new thoughts or suggestions would be appreciated.

Just went through the entire thread and listened to both videos....

First of all, this isn't even a question that can be asked until basic maintenance is done. It sounds horrible. This is due to:
1) Piano has severe design limitations.
2) 17 years old and probably hasn't had any real service -- either in new piano prep or in ongoing alignment, regulation, voicing, etc.
So, until those accumulated routine maintenance issues are taken care of, it will be difficult to locate anything else.

What I notice would be traceable to strings un-level (not mated to hammers) and grooved hammers that are hitting the strings with the sides of the grooves.

Once that is dealt with, then you could experiment/search for such things as...
--adding mass to the end of the long bridge
--looking for glue failure of some point of soundboard to rim joint
--crazily enough, I have encountered bass bridge aprons on the cheap Yamaha grands that have the grain of the apron running parallel to the length of the bridge. A split can open up in the apron right near the bridge body that is hard to see (especially under the accumulated dust and gunk) unless you look VERY carefully with good light for that possibility. The fact that the tonal weirdness is growing would be a clue that maybe such a split is opening up further.

Minor nitpick. Terms like G3 or C4 refer to pitches according to tuning aids. Actual notes are properly named as C-28 or E-44, etc.

Hope you get to the bottom of this.

I agree with Keith about the maintenance on the piano. Until that is done, there is no point in speculating about what other problems it has.

I also agree with Keith. You need someone who KNOWS What they are doing to work on this.

Pwg

This piano had the normal new piano breakin of being tuned every 3 months for the first year, it also had a damp chaser installed within that first year. Since that first year it has been tuned twice a year and sometimes three times. The owner is a piano teacher. It has the original strings, hammers and dampers. It has had a full regulation with hammers reshaped within the last 12 months (after the phantom tone appeared hoping that would fix it). It has been kept very clean with no accumulation of dirt and dust on the sound board. It is true that the hammers are not positioned square with the direction of the strings at the far left end of the treble bridge which is where the phantom tone is evident. The hammers hit the strings at an angle but they do strike the strings evenly. I pulled the action out again today just to recheck and the phantom tone is still there with the action out using a guitar pick on the individual strings and also by simulating a hammer strike. The phantom tone does not seem to have anything to do with the action.

I have re-read the entire thread on this to see if I missed anything. I am going to try adding weight to a bridge pin of the lowest treble bridge note with a small vice grip to see if it changes anything. Other than that the only thing I haven't tried that has been suggested is check for a loose sound board to rim joint. I am not sure how to do that so some advice would be appreciated. Thanks for your help.

Did you verify for a possible hidden crack in the bass bridge apron adjacent to the bridge?

kpembrook - thanks for your suggestion. I actually found a crack or possibly a seperation in the bass cantilever bridge. It is almost impossible to see. I am including a link to the video I took of it.
https://youtu.be/-vuq65atK9I
The strange part of the location of the crack in the bass cantilever bridge in refrence to the notes that have the phantom tone is that the hitchpins of the strings of note A37 are closest to the center of the crack. The notes affected by the phantom tone are A#26 through E32. The note most affected by the phantom tone is B27 but the hitch pins for it are at the end of the treble bridge which is beyond the end of the cantilever bridge. With the crack being closest to A37 I would have thought A37 would be the most affected but it sounds fine.
Any suggestions for how to fix this crack? Thanks