What do you want in a bass ?

[Ken McKay]

No I haven't noticed any correlation of F hole size to either volume or depth of sound. This is easy to test if you cover a portion of the soundhole, it either changes or not.

From what I have seen and heard, the things that do seem to matter are f-hole placement. This might be from their effect on the top plate resonances. Of course this is hard to prove. I am thinking that wider spacing effects the depth because of the flexibility of the plate goes up across the grain when spaced wider apart. This would effect depth of sound the most I think if the f holes are wider spaced. But the air inside needs to be able to reinforce the plate movement or it is wasted movement. So air volume and plate resonance needs to match. More of this can be heard as more fundamental to the tone.

Holes in the side of the upper bout don't seem to effect depth or volume much. I have played Arnold's ergo and I heard him say this also.

A hole in a place of maximum rigidity of the plates (tailblock) might theoretically highly effected sound. I have read that air pressure is highest there. Since the air pressure reinforces the plate vibration of both the top and back, a loss of pressure could decrease volume or depth.

[Arnold Schnitzer]

My non-scientific belief is that overly large f-holes are not good for tone. I will try to explain, based on a lengthy conversation I had about a decade ago with Tom Martin. We think that when the f-holes of a bass are really big, the sound jumps out of the bass quickly, creating the illusion of power. But when the f-holes are sized right, the sound has more time to roll around inside the corpus and it gets seasoned. Then the tone is more complex and woody, but the bass may not sound quite as loud in the immediate surrounding area. However, it will spread out into the hall and the audience will get more bass sound. Now this begs the question, "what is the right size?". My answer is, I know it when I see it. I think many of the Italian and English masters had it right, i.e., Panormo, the Testores, Ruggieri, etc. Contrarily, to my eye many of the Germans, Viennese, and some of the Americans make/made their f-holes overly large and open. And I have also had experience where very small f-holes seem to be holding back the power of a bass. I had the experience of enlarging them on a fine bass once, and I thought the instrument's power improved. Then again, other modifications were made, so I can't be sure.

[kurt muroki]

I always go for sound and volume before all else especially in chamber music where I am all alone and do not need to blend and my primary objective.

[Ken McKay]

Italians used proprotional geometry to place the f holes, Might that have a lot to do with them looking and sounding right?

Structuraly there is a lot going on in this area. The flexiblility of the plate in this area is highly effected by the placement of the f holes and their spacing, length, width of wings, slope and area. Arching, thickness and edge scoop also highly effect the structure of the top plate in this area. The bridge sits right in the middle and transmits the string movement directly to the top, right in the middle of the f holes. Theres a lot going on here!

Viols had C holes with a similar area as f holes. But the C holes covered much less horizontal grain so the plate was stiffer in that area. F holes evolved to create the more violin like sound that is now favored in larger concert halls.

So that is why I think f holes effect the sound a lot but not by air movement. The air pumping out of the box through the f holes creates a fullness to the sound. And I have noticed even cheap plywood basses have that whoomph, air sound. But the complex tone from a good bass comes from resonating of the bass body.

I just don't think the f hole size effects tone much by itself, unless they are too small or large. I am going to do some tests later this week.
edit: By allowing or not allowing air to pump, I should have said.

[Craig Regan]

How does f-hole placement effect the sound?

If the f-hole is moved closer to the center of the bass, is the sound deeper with more bass response?

Or does the bass have a more treble response if the f-holes are moved closer to the outer ribs?

This is just a theory; still looking for evidence.

[Arnold Schnitzer]

Originally Posted by Craig Regan

How does f-hole placement effect the sound?

If the f-hole is moved closer to the center of the bass, is the sound deeper with more bass response?

Or does the bass have a more treble response if the f-holes are moved closer to the outer ribs?

This is just a theory; still looking for evidence.

I would say you have that backwards. If the f-holes are close together, this necessitates a narrow bridge and then you have the bass bar and soundpost close together. When that is the case, the bass bar is constricted in its swinging. When the f-holes are farther apart, so can the bass bar and soundpost be, therefore resulting in a fatter, deeper sound. Also, when the f-holes are close to the corners you take advantage of the same effect that makes a bass player sound louder when playing out of a corner. I don't remember the name of this effect, but I bet Ken McKay does...

This does not mean you should place f-holes all the way to the edges, because your tonal balance will suffer. The f-hole upper holes should be spaced the same distance apart as the size of bridge you wish to use. What, design the instrument from the set-up backwards? Exactly.

[Martin Sheridan]

Thanks to all for input. Keep 'em coming.
martin

[Eric Rene Roy]

Originally Posted by Arnold Schnitzer

...What, design the instrument from the set-up backwards? Exactly.

Exactly what I did when designing our bass!