<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML xmlns="http://www.w3.org/TR/REC-html40" xmlns:v = "urn:schemas-microsoft-com:vml" xmlns:o = "urn:schemas-microsoft-com:office:office" xmlns:w = "urn:schemas-microsoft-com:office:word" xmlns:m = "http://schemas.microsoft.com/office/2004/12/omml"><HEAD> <META content="text/html; charset=utf-8" http-equiv=Content-Type> <META name=GENERATOR content="MSHTML 8.00.6001.18928"> <STYLE></STYLE> </HEAD> <BODY lang=EN-US link=blue bgColor=#d6dab1 vLink=purple> <DIV><FONT size=2 face=Arial>Del,</FONT></DIV> <DIV><FONT size=2 face=Arial></FONT> </DIV> <DIV><FONT size=2 face=Arial>It could be the waves returning to the player from the room. If the waves interact all kinds of things can happen. Each room will have it's character as well. Once those waves hit the air who knows what is happening. Refelective sound is very complex.</FONT></DIV> <DIV><FONT size=2 face=Arial></FONT> </DIV> <DIV><FONT size=2 face=Arial></FONT> </DIV> <DIV> <DIV><FONT size=2 face=Arial>Dan Berg</FONT></DIV> <DIV><FONT color=#008000 face="Arial Black">Berg Piano Services</FONT></DIV> <DIV><FONT size=2 face="Arial Black">407-884-1814</FONT></DIV> <DIV><FONT color=#0066cc size=2 face="Arial Black"><A href="http://bergpiano.com/">http://bergpiano.com</A></FONT></DIV> <DIV><FONT size=2 face=Arial>Your Home For Piano Help</FONT></DIV></DIV> <BLOCKQUOTE style="BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px" dir=ltr> <DIV style="FONT: 10pt arial">----- Original Message ----- </DIV> <DIV style="FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: black"><B>From:</B> <A title=del@fandrichpiano.com href="mailto:del@fandrichpiano.com">Delwin D Fandrich</A> </DIV> <DIV style="FONT: 10pt arial"><B>To:</B> <A title=pianotech@ptg.org href="mailto:pianotech@ptg.org">pianotech@ptg.org</A> </DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, March 18, 2011 3:14 AM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [pianotech] What is bloom,</DIV> <DIV><BR></DIV> <DIV class=WordSection1> <P style="LINE-HEIGHT: 15pt; MARGIN-BOTTOM: 9pt" class=MsoNormal><SPAN style="FONT-FAMILY: 'Cronos Pro','sans-serif'">Yes, well, I continue to wonder just what it is that we’re actually hearing. Below is an idealized illustration of what is happening at, and following, hammer impact. (It’s a little more idealized than I would like but I don’t have any of my own on this computer. This one is borrowed from the Five Lectures website.)The hammer strikes the strings at about 3 sec. There is a chaotic spike immediately following (the period of chaos is typically a bit wider than shown here). The sound immediately begins to decay at some fairly rapid rate but, for this note, at around 5 sec. the rate of decay changes. <o:p></o:p></SPAN></P> <P style="TEXT-ALIGN: center; MARGIN-BOTTOM: 12pt; MARGIN-LEFT: 0cm; MARGIN-RIGHT: 0cm; mso-margin-top-alt: 12.0pt" class=MsoNormal align=center><B><SPAN style="FONT-FAMILY: 'Cronos Pro Light','sans-serif'"><IMG id=Picture_x0020_4 alt="Description: Description: Fig 1. Typical decay of a piano tone as illustrated by the sound pressure level versus time (Eb3 = 311 Hz). The decay process is divided into two parts; an initial attack part with a fast decay (prompt sound) followed by a sustained part with slow decay (aftersound)." src="cid:B10E9FFF9C4C482C80686E78D8A24857@BergInternet" width=301 height=223></SPAN></B><B><SPAN style="FONT-FAMILY: 'Cronos Pro Light','sans-serif'"><o:p></o:p></SPAN></B></P> <P style="LINE-HEIGHT: 15pt; MARGIN-BOTTOM: 9pt" class=MsoNormal><SPAN style="FONT-FAMILY: 'Cronos Pro','sans-serif'">From what I’ve been able to figure out, the knee (at around 5 or 6 sec.) is where the strings vibration pattern changes from a predominately transverse motion (perpendicular to the bridge) to a more random, or rotational pattern. The note is still dying out but at a slower rate. It continues thus until the sound dies out or, as in this illustration, the damper drops.<o:p></o:p></SPAN></P> <P style="LINE-HEIGHT: 15pt; MARGIN-BOTTOM: 9pt" class=MsoNormal><SPAN style="FONT-FAMILY: 'Cronos Pro','sans-serif'">In all the samples I’ve recorded and studied over the years I’ve never seen the sound level increase after hammer impact and that first chaotic wave pattern. They all end up looking like some variation of this. More ragged and uneven sometimes but they follow this generally pattern. <o:p></o:p></SPAN></P> <P style="LINE-HEIGHT: 15pt; MARGIN-BOTTOM: 9pt" class=MsoNormal><SPAN style="FONT-FAMILY: 'Cronos Pro','sans-serif'">It leaves me wondering if what we think we hear as “bloom” isn’t at least partially—perhaps predominately—psychoacoustic. Our ears—or our brain’s interpretation of what our ears detect—quickly become accustomed to that rapid drop-off following the chaotic hammer impact and, when the waveform gets to the knee and the decay rate slows (sometimes dramatically) we interpret the change as “bloom.”<o:p></o:p></SPAN></P> <P style="LINE-HEIGHT: 15pt; MARGIN-BOTTOM: 9pt" class=MsoNormal><SPAN style="FONT-FAMILY: 'Cronos Pro','sans-serif'"><o:p> </o:p></SPAN></P> <P style="LINE-HEIGHT: 15pt; MARGIN-BOTTOM: 9pt" class=MsoNormal><SPAN style="FONT-FAMILY: 'Cronos Pro','sans-serif'">ddf</SPAN><SPAN style="FONT-FAMILY: 'Comic Sans MS'; COLOR: navy; FONT-SIZE: 11pt"><o:p></o:p></SPAN></P> <P class=MsoNormal><SPAN style="FONT-FAMILY: 'Comic Sans MS'; COLOR: #632423; FONT-SIZE: 10pt">Delwin D Fandrich</SPAN><SPAN style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #632423; FONT-SIZE: 10pt"><o:p></o:p></SPAN></P> <P class=MsoNormal><SPAN style="FONT-FAMILY: 'Comic Sans MS'; COLOR: #632423; FONT-SIZE: 10pt">Piano Design & Fabrication</SPAN><SPAN style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #632423; FONT-SIZE: 10pt"><o:p></o:p></SPAN></P> <P class=MsoNormal><SPAN style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #632423; FONT-SIZE: 10pt">6939 Foothill Court SW, </SPAN><SPAN style="FONT-FAMILY: 'Comic Sans MS'; COLOR: #632423; FONT-SIZE: 10pt">Olympia, Washington 98512 USA<o:p></o:p></SPAN></P> <P class=MsoNormal><SPAN style="FONT-FAMILY: 'Comic Sans MS'; COLOR: #632423; FONT-SIZE: 10pt">Phone  360.736.7563 — Cell  360.388.6525</SPAN><SPAN style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #632423; FONT-SIZE: 10pt"><o:p></o:p></SPAN></P> <P class=MsoNormal><SPAN style="FONT-FAMILY: 'Comic Sans MS'; COLOR: #632423; FONT-SIZE: 10pt"><A href="mailto:del@fandrichpiano.com%20"><SPAN style="COLOR: blue">del@fandrichpiano.com </SPAN></A></SPAN><SPAN style="FONT-FAMILY: 'Comic Sans MS'; COLOR: #632423; FONT-SIZE: 10pt">— </SPAN><SPAN style="FONT-FAMILY: 'Comic Sans MS'; COLOR: #632423; FONT-SIZE: 10pt"><A href="mailto:ddfandrich@gmail.com"><SPAN style="COLOR: blue">ddfandrich@gmail.com</SPAN></A></SPAN><SPAN style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: navy; FONT-SIZE: 11pt"><o:p></o:p></SPAN></P> <P class=MsoNormal><SPAN style="FONT-FAMILY: 'Comic Sans MS'; COLOR: navy; FONT-SIZE: 11pt"><o:p> </o:p></SPAN></P> <P style="MARGIN-LEFT: 36pt" class=MsoNormal><B><SPAN style="FONT-FAMILY: 'Tahoma','sans-serif'; FONT-SIZE: 10pt">From:</SPAN></B><SPAN style="FONT-FAMILY: 'Tahoma','sans-serif'; FONT-SIZE: 10pt"> pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] <B>On Behalf Of </B>Dale Erwin<BR><B>Sent:</B> Thursday, March 17, 2011 5:20 PM<BR><B>To:</B> pianotech@ptg.org<BR><B>Subject:</B> Re: [pianotech] What is bloom,<o:p></o:p></SPAN></P> <P style="MARGIN-LEFT: 36pt" class=MsoNormal><o:p> </o:p></P> <P style="MARGIN-LEFT: 36pt" class=MsoNormal><SPAN style="FONT-FAMILY: 'Comic Sans MS'; COLOR: black; FONT-SIZE: 10pt">Del<BR>  Understood. I can't measure it empirically either. Fortunately we can hear it.<o:p></o:p></SPAN></P></DIV></BLOCKQUOTE></BODY></HTML>