Very very amazing videos! But I notice two things. First, (referring back to my previous post), in the A#14 video I am not really aware of ever seeing a wave for the fundamental. Does one actually exist? Second, there is something funny going on in that you can actually see the waves on the two strings go out of sync (phase) with each other. String length differences? Slightly out unisons? Compare to the tri-chord video where the three strings are dead on in sync (phase) for the entire time. In any case, very amazing video. Thanks Stephen. Geoff Sykes Assoc. Los Angeles -----Original Message----- From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On Behalf Of Stephen Birkett Sent: Sunday, August 14, 2005 10:23 PM To: Pianotech Subject: Re: string termination >I don't plan to hear or measure anything. I only want to look and >see what is happening to the string. A commendable objective Carl. To whet the appetite a bit take a look at the high speed images I have on my website...some strings, dancing dampers, and bridge pins. These were simply taken for interest and to test out the system, and definitely not under controlled circumstances, so they won't answer the detailed carousel (aka merry-go-round to those on the other pond-side) of questions about strings and terminations. They do show the complexity of the situation and the difficulty of making causal generalizations. There is a plan to tackle this question as part of our grand scheme of things here. First we have to learn how to be creative with the equipment, so we can get multi-directional synchronized images and see what's going on in 3-D with only one camera. My plan is to isolate single variables that can affect string motion (e.g. see Ron's long list), maintaining all bar one which gets adjusted and the effect on the string monitored. Needless to say this requires a precisely repeatable key actuation so comparisons at successive times are meaningful, but that one we have licked already. The ftp server on my usual website is out of action at the moment, so best go to the mirror site I have. The high-speed stuff is at http://fortepianos.com/high%20speed%20imaging.htm Note carefully the instructions given for getting your system set up to play these. The compression is extreme (each video starts raw at 500MB and compressed to about 5MB) to make them manageable files, so you'll need to get the correct video codec installed if you don't already have it. Stephen -- Dr Stephen Birkett Associate Professor Department of Systems Design Engineering University of Waterloo Waterloo, Ontario Canada N2L 3G1 E3 Room 3158 tel: 519-888-4567 Ext. 3792 fax: 519-746-4791 Piano Design Lab E3-3160 Ext. 7115 mailto: sbirkett[at]real.uwaterloo.ca http://real.uwaterloo.ca/~sbirkett _______________________________________________ pianotech list info: https://www.moypiano.com/resources/#archives
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