Difference from flat back vs. arched back?

[Flat Bass]

Can anyone tell me the difference? I own a knilling 3/4 arch carved top flat back. My friends all have arch backs?

[SLaPiNFuNK]

flat backs tend to be more punchy sounding... they project sound better a little better but have a different tone to them... more direct...

I think...

[Aaron Saunders]

IIRC, they're hellish to maintain. Then again, I don't hang out in the basses forum here too much, so take my comment with a grain of salt.

[tbassist4]

I forget where I heard this from, but I was reading online about bass history and I beleive it said that rounded backs or flat backs made no difference in sound, as well as violin corners. It was talking about the point in time when the violin family first became prominant over the viola de gamba family of instruments. This may be unreliable, and I own only one bass, so from personal experience, I have no idea.

EDIT: Ah, right here on talkbass: Flatback vs. Roundback , it's post #6, the original comment from Paul Brun. True also about the violin corners...If the sources are correct. So it seems it may have a slight effect, but none really for the most part.

[5stringDNA]

Originally Posted by tbassist4

I forget where I heard this from, but I was reading online about bass history and I beleive it said that rounded backs made no difference in sound, as well as violin corners. It was talking about the point in time when the violin family first became prominant over the viola de gamba family of instruments. This may be unreliable, and I own only one bass, so from personal experience, I have no idea.

We have been over this issue on more than one occasion, and the consensus always seems to turn out that "it just depends on teh particular bass." I suppose it is possible to construction a complicated physics model and show which design woudl theoretically disburse sound better, but as Ken said, there are so many variables that issues becomes ridiculous.

As far the violin vs gamba thing, the only case I could see for that making a difference is the total internal volume. A bigger bass is going to have more room to reproduce the proper registers and get a fuller sound, so if the volume chang eis significant, it could matter, such as in the NS Clevland and La Scala. The caveat, however, is that on a comparison like that, the true difference is the size of the upper bout, which is FAR more significant than the corner style as far as volume and texture goes. All things compared, the type of corners probably has insignificant influence on the volume and tone, but I could be wrong...

[Just some guy]

An interesting related link...
http://iwk.mdw.ac.at/Forschung/pdf_d...ssertation.pdf

[Don Higdon]

Originally Posted by Just some guy

An interesting related link...
http://iwk.mdw.ac.at/Forschung/pdf_d...ssertation.pdf

I'm sure the guy meant well, but I regard a dissertation like this as essentially useless. So shoot me.

[5stringDNA]

Not too mention spending the tiem to read 140 pages of it.. yikes- no thanks!

[Don Higdon]

Originally Posted by KSB - Ken Smith

Now, on the Corners you can take any photo of any Bass and draw the other type of corner turning a Gamba into the Violin shape and Vicea versa. That's a nicea..

Ok.. Look at the blocks inside the corners and draw them on the front. Do this with both shapes to see if one takes up more or less of the airspace inside or only the corner extends inside the violin point of the corner. See if the only the outer shape changes rather than the inside as well or if there is change how much comparative air volume.

Flawed methodology. Totally. The only way to measure the volume is to fill the bass with water, then pump it into a tub and note the water line with a very fine pointed pencil.

[Mike Crumpton]

You know, the dissertation conclusions remind me of a test on wine tasting (I know he claims people didn't know what bass they were listening to but hey, they had a 50/50 chance and if the unused basses were in the same room?). When describing red wine, people and experienced critics talk about blacberries and plum and any darn fruit that is red so they put red dye into a whilte wine and asked them to describe it and guess what - all the descriptions used red fruits as comparitors.

So the round back basses sound 'round' and the flat backed basses sound 'flat' - (not me mate - i usually play sharp :-) ) and you can't always tell the differnce - well now, what can I say but agree with Donno.

Tallking of agreing with Donno, what's the betting that Ken is using hte Donno method to tes the internal volume of his basses? :-)

[Johnny L]

From my experience, the essential difference is that one back is flat while the other is arched.

[Don Higdon]

Originally Posted by Johnny L

From my experience, the essential difference is that one back is flat while the other is arched.

There you go again, generalizing.

[billyfalconer]

Originally Posted by Mike Crumpton

... When describing red wine, people and experienced critics talk about blacberries and plum and any darn fruit that is red so they put red dye into a whilte wine and asked them to describe it and guess what - all the descriptions used red fruits as comparitors.

So the round back basses sound 'round' and the flat backed basses sound 'flat' - (not me mate - i usually play sharp :-) ) and you can't always tell the differnce - well now, what can I say but agree with Donno.
...

Or bows with black hair sound darker than bows with white hair.

[drurb]

The comment by 5StringDNA:

"I suppose it is possible to construction a complicated physics model and show which design woudl theoretically disburse sound better, but as Ken said, there are so many variables that issues becomes ridiculous."

comes closest to the heart of the matter. I will not comment on the dissertation except to say that I would not dismiss it out of hand. In any case, this a matter of what is referred to as within- and between-variance. Here is what I mean. It may, indeed, be the case that, theoretically speaking, there are overall or general differences in the acoustics and the perceived sound of flat backs vs. round backs.

Think of them as forming two distributions, if you will, along the relevant dimensions. The question then becomes whether the variation measured across individual instruments within a class (the within-variance) is so large as to approach or overwhelm the variation measured between instruments across the two classes (between-variance). This is a fundamental concept in evaluating any hypothesis regarding meaningful differences.

Now, Ken's position, translated into scientific terms is that the ratio of these variances makes generalizations across the classes meaningless. He may be quite correct.

Here's a more intutive example. Are men taller than women? Well, indeed, as a group they are. If you, however, needed a person who is 5'10" tall, you would be wise, a priori, to choose a man if all you can do is specify man or woman. You could really get fooled though! You would have done better to directly choose a person of the required height. Likewise, it seems, that if you want a bass having particular sonic qualities, you would do well to choose that bass on the basis of just those qualities rather than setting out to buy a flat-back or a round-back.