Hi Dale. Very late in on this one... but just so. I've listened to both fans and anti-duplexers both front and back and taken both as seriously as I can. My own judgement is that if the things are appropriately adjusted, then the sound of the instrument is most definitely enhanced. Really cant see how anyone can come up with any other conclusion myself. Well... I can understand that some may not like the contribution the finely adjusted front duplex makes... but then to each their own. I like it. As far as your experiment is concerned. You didnt mention whether any attempt was made to <<tune>> the rear duplex and if so what you did. I know tuning the rear duplex is a hot item... but I recently conclusively confirmed that the thing is most definitely <<tuneable>> and in fact the tension on these lengths is more stable then the speaking lengths as long as your usual tuning technique does not involve large movements of the tuning pins. As for getting the front duplex working well... and appropriately adjusted... I again recommend Ed McMorrows book. He does explain in easy language the basic physics of how the thin capo profile works to allow the string to flex about the termination. This is essential to a good functioning duplex. Otherwise its hard to avoid getting all kinds of what most folks would call string noise. Cheers RicB Duplexers AS a follow up to my original post Last night we had a roundtable discussion at our chapter meeting regarding my experience as listed below. As you can imagine, in a group of independent piano technicians there were a variety of opinions & intelligent conjecture offered. My contention was that if the duplex scale is such a great invention it should produce a noticeable effect upon the listener & content of the sound emanating from any piano with a duplex scale should be enhanced. The short version is that Bob Davis suggested an experiment which, any one with a roll of masking tape can do. Our test subject, was 1953 Steinway B with an original board,new strings & action. The voicing is in the range of what many people would find acceptable. We enlisted one of members to play the same piece of music after taping off the three rear duplex bars. As he played we took of the tenor area tape. The clarity sustain & flavor of the piano tone was greatly more appreciated by all present and of all areas & most pronounced of the 3 individual sections. We then did the same thing with capos section 2 & 3. Similar result in capo 1. Capo 2 was less obvious but still preferred.(i.e. .increased sustain,clarity & color. We taped off the front duplexes as well & a similar outcome was observed though not nearly as pronounced. One thing to note about the front duplexes and that is that on this 1953 B the draft angles are significantly steepr than most B I've encountered & bleed thru is not an issue & sustain is good. Also lightly pressing your finger on the front duplexes really kills the sustain as it apparently limits the rocking of the string across the capo string contact area. In our follow up assessments I was surmising that the more efficient & strong the tone of a sound board is the greater the duplex effect may be. So try it yourself & see if it's just smoke & mirrors. Whether it is a desirable affect....... is your call. I personally like it. Dale
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