ooops...? David Ilvedson, RPT Pacifica, CA 94044 ----- Original message ---------------------------------------- From: wbis290 <wbis290 at aol.com> To: caut at ptg.org Received: 5/10/2009 3:34:55 PM Subject: Re: [CAUT] Semantics >Hi Gary, >I think that at some point this whole discussion has become one of being >unbelievable. I have been an RPT for thirty nine years and have seen things like this >the whole time that I have been a member. There are times when people seem to >get too technical and over state things. Sometimes it is from a good amount of >knowledge and sometimes I think that it is just talk to hear one's self. We had a >member of the Guild who makes soundboards give our chapter a talk on the science >of soundboards. This gentleman was invited to go in with Baldwin on studies of the >soundboard. After much research, it was discovered that the science of >soundboards was mostly guess work. What looked good in theory and research was >always thwarted by the fact that each individual piece of wood reacted differently >than what was expected. In short too many people are trying to reinvent something >that has worked great for years regardless of what terms are used. >God bless >Bill Balmer, RPT >University of Findlay and Ohio Northern University >In a message dated 05/10/09 16:08:08 US Eastern Standard Time, >escapement at comcast.net writes: >Reading my post back after submitting, I realize I might come across as a >bit stodgy. Not my intent. >I have a great deal of respect for the contributors here--I have learned a >lot about piano technology and tuning in the last month or so reading this >list (and pianotech). >It's not my intent to offend anyone here and I should have prefaced my post >with my initial thanks for all the contributors. This list and pianotech >are a godsend to me and I appreciate all of you and the vast knowledge here. >I also appreciate your generous spirit. >But I honestly find this issue a bit confusing. >Gary >-----Original Message----- >From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of >Escapement >Sent: Sunday, May 10, 2009 4:48 PM >To: caut at ptg.org >Subject: Re: [CAUT] Semantics >I'm new to the piano tuning world but I do have a background in computer >science and have worked with signal processing. I just read through these >posts and have to admit I was thrown for a bit of a loop when I read that >it's now agreed that the soundboard should be called a "transducer." >My understanding of a transducer has always been that it is a device that >takes one form of information or energy and converts it into another form. >(Like the speaker example given where *electrical current* is converted to >physical vibrations through the electromagnetic voice coil). The speaker >isn't a transducer because the voice coil vibrates the membrane -it's a >transducer because it takes the *electrical current* in the wire and >converts it to vibrations *(sound)*. In the same way that a microphone is a >transducer because it takes *sound* and converts it to an *electrical >signal*. >But with the soundboard I don't see this conversion. My understanding of >how a piano works is that the vibrations in the strings are coupled with the >vibrations in the bridge/ soundboard. But it's vibrations to >vibrations-sound (though very slight) to sound (much louder). I suppose you >could call the piano itself a transducer in that it (along with the player) >takes the information on the music page and converts it to sound. But >calling the soundboard a transducer seems odd to me. >I agree that technically, the soundboard doesn't amplify the string energy, >per se, but it does make the sound louder because it is far more efficient >at taking that little bit of energy and converting it into sound energy. >My understanding of the soundboard is that it is a *resonator*-that it >reinforces and emphasizes the sounds generated by the strings, that the >strings and the soundboard work together to make the sound. It is this >*resonance* that increases the sound output of the piano. >But I don't see the big deal in saying the soundboard amplifies the sound. >Though it doesn't amplify the energy, acting as a *resonator* it does take >that energy and (a great deal more efficiently) converts it to a much >*louder* sound. And we measure loudness by *amplitude* of the sound/sine >wave. So, saying the sound is "amplified" by the soundboard seems >reasonable to me. >I mean, are we supposed to say that the soundboard "transduces" the sound to >higher amplitude? Is that really more instructive than, "the soundboard >helps to amplify the sound?" To me, it just sounds confusing. Again, my >understanding is that the soundboard acts as a resonator and reinforces the >sounds made by the strings to increase the sound output. to make it louder. >to amplify the sound. >I don't see a transducer in the soundboard. >When you strike a tuning fork and place it against a table, don't you say >the table amplifies the tuning fork? Would anyone really argue with this? >Would you really say the table becomes a transducer? Would it be more >correct to say that the table resonates along with the fork and increases >the sound output? The table isn't a transducer. the fork vibrates, the >table vibrates (resonates). And part of the definition of a resonator is >that it "amplifies" vibrations (but again, in the sense described above). >With respect, >Gary Hodge >PTG - ASSOCIATE MEMBER >-----Original Message----- >From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Fred >Sturm >Sent: Saturday, May 09, 2009 10:22 PM >To: caut at ptg.org >Subject: Re: [CAUT] Semantics >On May 9, 2009, at 3:46 PM, David Love wrote: >> However, why can't one say "the volume of sound produced >> formerly limited by the inconsequential mass of the vibrating string >> alone >> is increased when the energy is transduced to the soundboard whose >> greater >> mass and area allow for the greater movement of air". Substitute the >> colloquial meaning of amplified for increased and I don't think the >> physical >> world as we have come to know it will cease to exist or all soundboard >> science will be endangered. > Yes, a "larger volume of sound" is produced by a vibrating string >coupled to a soundboard than is produced by a string vibrating but not >coupled to a soundboard. But I would ask you to read Del's posts >carefully. It doesn't really matter that an uncoupled string makes >sound. The driver of a speaker's membrane makes negligible sound. The >sound is produced by the vibration of the speaker membrane. The >speaker membrane isn't increasing the sound of the driver. It is >producing sound in response to the driver's vibration (the driver's >vibration causes the membrane to vibrate, which moves air molecules). >This is very much analogous to what happens with a string and a >soundboard assembly. > This doesn't mean that someone who thinks that a soundboard makes a >string sound louder is stupid. It does mean that someone who holds >that opinion is ill-informed. It is a natural and even logical kind of >misinformation, which is why it is so widely held. It doesn't help >that advertising folks for piano manufacturers have been spreading the >misinformation. > In any case, it is important to understand the mechanics. And this >ties back to the original topic, which had to do with the theory that >string vibrations could be coupled, through accujust hitchpins, to the >plate, and could make the plate vibrate/resonate in some way. If we >want to try to see if the analogy between a stake driven into the >earth, abraded by a hoe, and a string terminated on a vertical pin, >driven into a hole in a mass of cast iron, has any validity, well, it >helps to have some knowledge of the mechanics/physics involved, and to >use words carefully in describing what happens. > All the hurt feelings and notions of disrespect and anger are very >much beside the point, and waste a lot of our collective time and >energy. Let's lose those arguments, okay? > >Regards, >Fred Sturm >University of New Mexico >fssturm at unm.edu
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