Regulating brightness

[DoctorAl]

I've recently picked up a cheap baby grand (Challen, 1974, 5' long) as a stop-gap second departmental piano until we can afford something really good. As far as I know it hasn't been played much recently, and was previously in a domestic situation and has probably never been regulated. The hammers have deeper grooves than most I've seen, but I don't tend to come across seriously overused pianos. The tuning seems very stable.

The tone is inconsistent across the range, although fairly even from note to note. The lowest notes are as you'd expect on a baby grand, but then there's a pleasant enough tone until you reach a few notes above middle C when things start becoming muffled. One higher note randomly sings out just as I'd want. The top octave is all thump.

I had the action out today getting rid of thirty years of dust and detritus, and it seems in good order (Schwander). My initial diagnosis is that the hammers are likely too soft/grooved and damping the higher harmonics, but I am no expert.

So: if it is the hammers, are things likely to improve without interference purely from it being played again? Or as there are grooves in the hammers already is it more likely time to get it professionally regulated? (don't worry, I'm not about to get the Dremel out myself!) Can anyone think of other plausible reasons for the muffled treble tone?

thanks,

Al

[mdw]

Bridge unglued from soundboard?

[jackg]

If the hammers are worn, it may be you are getting an uneven line contact between the hammer and each string instead of a point contact, so it could be the problem. One part of the hammer hits the string then another part hits it not so heavily and acts as a damper.
I had the hammers on my upright piano refaced along with an action refurb, made the world of difference. There was just enough felt on them. I asked about three or four techs or tuners for their advice, some said replace the hammers, the man I gave the work to said that they can be refaced. Ex chief tech of main dealer in Bristol.

Regulation is pointless until you address the hammers.

[DoctorAl]

Thanks for your thoughts. mdw, am I right to presume that an unglued treble bridge would result in tuning instability? As everything looks normal, is there an easy test to determine whether this could be the case? Would the isolated brighter note support or scotch this theory?

jackg, that was my thought too. There looks to be sufficient felt on the hammers for refacing, although I am not an expert. My only query with this is that new pianos often become brighter over time, so I wondered if this one, not having been played much of late, might do likewise as the hammers got used to being played again.

Is hammer refacing something usually done on location or in a workshop?

Al

[jackg]

Hammers are voiced with a voicing tool to tone them down or doped to brighten the sound can be adjusted to suit the room. The tech took the action away with him to work on. the hammers are removed and refaced in a group of say 10 ish I think.
I would advise getting an opinion from a local tech or two, if the hammers are worn other parts of the action are likely to be worn.

[mdw]

am I right to presume that an unglued treble bridge would result in tuning instability?

Yes, I see more bass than treble gone but either way you will have other problems to deal with as well.

[DoctorAl]

As there are no other problems yet, and the tuning seems very stable (allegedly three years and two moves, and was in better tune than the 2005 Kemble it's sitting near to while it acclimatises) I'm inclined to think the bridges are fine.

Fortunately it turns out my boss knows an ex-tech and we may be able to get an accurate verdict from someone who definitely doesn't want the job themselves! I'll report back once someone has seen it in person.

Al

[mdw]

we may be able to get an accurate verdict from someone who definitely doesn't want the job themselves!
Al

Trust me if its the treble bridge there wont be many people who will want the job!

[Bill Kibby]

Before you start worrying unnecessarily about major repairs, think. You say the hammers are worn, this has two effects: Firstly, the surface can grip the string, and remain in contact with it longer than it should, so this has a muffling effect. Your tuner should be able to reface the hammers if there is enough felt. Secondly, the hammers will, if they have done that much work, have become harder inside the felt. This will make the treble louder and harsher so, again, of there is enough felt, your tuner will be able to tone the hammers. This is nothing to do with regulating, but there are mechanical problems which might be solved by adjustment. It's pointless going on with the debate, you need to get a proper tuner-technician in to deal with it. If you're in East Anglia, email me.