[CAUT] muting center string

[A440A@aol.com]

Bob writes:

<< Ed Foote wrote about tuning unisions by tuning the
outside strings by ETD then dropping in the center
string aurally.  

My question is do you have a way of muting the center
string only so you can listen to the two outside
strings alone before tuning the center string? >>

Greetings, 
   This ain't the first time I haven't been very clear about what I was 
doing!  mea culpa
In tuning a trichord unison, I tune the bass side string to stop the lights 
on a SAT while I have a wedge mute between the center and treble side strings. 
Then I move the mute to be between the center and bass side string and tune 
the treble side to the SAT.  THEN, before completely withdrawing the mute, I 
keep it against the untuned middle string and listen to the pair, (bass and 
treble side) strings.  
     I want to hear a totally dead unison between the two.  If they are, I 
then take the mute all the way out and pull the center string sharp before 
letting it down to a point where the unison sounds clear and full.  
If they aren't, I recheck them against the SAT. If they still stop the 
lights, I will go ahead with the center string, trying to merge all the phasing 
together.  There are three different relationships involved in the trichord, ie, 
left/center, right/center, left/right.  Putting them together in a consistant 
fashion is what makes the sound I am looking for. 
    If I use the SAT for all three strings, the majority of the unisons will 
be fine, but there will be a certain percentage of them that sound 
differently.  This will make those few stand out.  By letting my ear make the final 
overall decision on each note, I feel that I can leave a set of unisons that are 
more consistant, and consistancy is what the pianist reacts to.  As an example,  
I once tuned an entire piano with 1 cent purposefully left in the unisons, 
all on the sharp side.  Each one had a slight, but noticeable "movement" in 
there, but the overall impression to the customer was that the piano was 
beautifully in tune!  However, he remarked later that the tuning didn't seem to "last 
as long".  I ascribe this to the fact that the unisons were already at their 
limit of tolerance and it didnt' take them long to move into objectionable 
territory.  
   I might add that I tune with a lot of tension in the top string, and on 
checking up on my work, (many of these pianos are tuned numerous times a year)  
I find that a string that does move will just as likely go sharp as flat. So, 
it is to my benefit that I start the unisons off as close to together as 
possible. 
Hope this helps, 
Regards,  
Ed Foote RPT 
http://www.uk-piano.org/edfoote/index.html
www.uk-piano.org/edfoote/well_tempered_piano.html