position of aperture in soundboard - IV kit

[fretman314]

I ordered up my IV kit without sound hole and now need to put one in. Can anyone give me guidance as to where either F-holes should go or a single oval sound hole. I've not quite made my mind up yet which to go for! In the mean time I small try to print out a 1-to-1 picture as guidance. There have been several posted on threads, but not many with a full frontal view.

[sblock]

I ordered up my IV kit without sound hole and now need to put one in. Can anyone give me guidance as to where either F-holes should go or a single oval sound hole. I've not quite made my mind up yet which to go for! In the mean time I small try to print out a 1-to-1 picture as guidance. There have been several posted on threads, but not many with a full frontal view.

Not sure why can't you use the many pictures available online as your guide. Anyway, for f-holes on a Gibson F5 style instrument, the inside points in the middle of the f-holes should, ideally, line up with the position of the bridge. For an oval hole, the top edge of the hole in a Gibson A4 style instrument is generally positioned immediately under the 22nd fret. Does your kit have 12 or 14 frets to the body? This matters!

[fretman314]

Thanks for the info. As I mentioned there aren't many that give a full on view. I have found one and will enlarge it to full size (good job I have a large monitor!) before tracing it. Oval hole ones are a little more difficult to find but I believe a member here did a blog of his build but I can't find that at the moment. On the IV kit I believe the body starts around fret 13/14. I'll check for sure when I'm back in the shed.

[rcc56]

The top edge of the oval hole on both a real F-4 and a real A-4 is 9 7/16" from the tail end of the top; in other words the southern most point on the top. The oval is 2 7/16" in horizontal width and 1 7/16" in vertical length.

While I can confirm that the upper edge of the oval hole lines up with the 22nd fret on an A model, I will note that it is halfway between frets 20 and 21 on the F model. To the original poster, be aware that these measurements from old Gibson oval mandolins are all for mandolins with short necks. If you have a long neck kit [which is probable], you are going to have to decide whether you want to adjust the soundhole position to accommodate the longer neck. If you leave it in the same place in relation to the tail of the instrument, you will be reducing the distance from the soundhole to the bridge. I don't know how that will affect the tone. If you move it up to accommodate the new fingerboard position, it will have a different effect on the tone. I don't have an answer to which solution is better for the tone of the instrument.

On an F-5, a vertical line drawn from the outside edge of the 4 3/8" wide bridge base should intersect the center of the upper circle of the f hole. If you want to do the math, you can find the distance from the centerline-- I'm feeling too lazy right now. The extreme upper edge of the f hole is approximately 8 1/4" above the tail end of the top, measured vertically. Any good F-5 blueprint should clarify this.

[Willie Poole]

I am not a builder but from what I have seen on mandolins with the FF sound holes the little notches in them are positioned so they line up with the bridge placement which is 13-7/8 in from the nut.....I am sure that if you were to do a search here on the Café you could find some photos with a more accurate info...

Willie

[HoGo]

On F-5 the line on which bridge sits is 6" from crosspiece. The 15th fret is just at the upper edge of crosspiece so I would say 6 1/16" from where your 15th fret will be.