<HTML>.      Del   I think we said the same thing using different words although it would have been helpful if I'd used the word rib in relationship to rib/ or board crown. I was responding to the earlier post speaking directly about rib curvature so I didn't think further clarification needed. Anyway, now no one should be unclear. >>>>>Dale Erwin <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px"><BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">        Dittos Terry.     I Know of no on using less crown in the treble. At least many are using 60ft. thru out and many of us increasing radius into  the treble. I think the confusion is that a 60 ft. curve on a 40 inch rib appears to have proportionally more crown (7-8 mm) than a 15 inch rib with a 25 ft. curve ( 1.5mm) when observed visually. >>>>>Dale Erwin>>>>>>>> </BLOCKQUOTE> Dale & Terry, Let's define our terms here. When talking about increasing or decreasing crown we're generally referring to the amount of visible curvature in the system -- a particular rib or the whole board. So an increase in crown means the system has more visible curve and a decrease in crown has less. It's the radius of the curve that is changing. Now, if we're talking about radius then a rib cut to a 40' radius has more crown than does a rib cut to a numerically larger 60' radius. Regardless of length. We use ribs of smaller radius (larger crown) in the treble and ribs of larger radius (smaller crown) in the bass. At least I think that's what Terry was referring to? Del </BLOCKQUOTE> </HTML>