first dreadnaught - bracing question

[deadedith]

I'm working on the one-month Ditson.
Re: bracing - this is the largest bodied guitar I've built, and I would like to ask experienced guys how to handle the bracing. I'll be using the standard bracing pattern, but reading up on it I ran across a persuasive (to me) article by Dana Bourgeois, in which he stated that in order to get a better treble response in dreds, he beefs up the treble end of that x-brace leg by not scalloping it; in other words, he only scallops the bass side.

Thoughts?

[Ken Hundley]

I did that on my first jumbo.....love the sound, but can't guranteee thats the reason for it.

[deadedith]

How is the treble response on that jumbo?

[kencierp]

Steve Klein most likely would tell you that the suggested change would have no effect? I would "guess" that if there is an audible difference its not an increase in the treble but rather a suppression of the bass response.

[kencierp]

Also, it been a while since I read his books, but I seem to remember that Roger Siminoff states that the pointy nodes on scalloped braces do nothing to impact sound -- and that over all "lighter" unrestricted bracing was/is the key to a well driven sound-board.

[tippie53]

As Ken points out , often things will appear more defined by restricting the opposite . One also needs to be careful that over scalloping can cause other issues . This is about getting a balance . Understanding the physics of what happens helps you to know what the cause and effects relationship are .
When you take material off the top or bracing you are allowing the top to move in different nodes . At the same time you are influencing the headroom. A guitar for a bluegrass flat picker will be a bit different than a blues fingerpicker .
There is no one perfect bracing scheme for all guitars . In the end it is about strength to weight ratio. When you get into the top and how the bracing works , look at the stress loading . You can be more efficient in load handling in tension than in compression . Look at how the top takes rotational load , compressive load and tensional loading.
Keep a building log and you will soon learn how to adjust the top for what you are looking for . Sound hole size can also affect bass response , and some builders like heavier tops than others . Many opinions and some experts can add more confusion . That is why this is an Art. there are so many variables .

[deadedith]

Here is a pic of Dana's bracing I was referring to.
Could this inhibit bass in your opinion? If so, it would theoretically allow the treble to stand out?

I have a BBE Sonic Maximizer for my stereo system. It is not an eq, but instead allows me to alter the time lapse between the treble hitting the speakers and the bass hitting the speakers. You don't hear a lapse, of course, or change eq, but the effect is to allow the treble to shine through before the bass signal. It makes a huge difference in sound. Maybe there is a parallel to the bass dampening effect of certain bracing.

[Tony_in_NYC]

A tighter soundboard will accentuate treble response, looser accentuates bass. I think Dana's bracing strikes a balance. Less bass means you hear more treble. Since it's a dread, the bass will be there unless you brace with 2x4's.

[kencierp]

Seems the sound board would have a little more mass - which not sure what the results might be -- interesting that the heavier non-scalloped brace is on the treble leg -- hmmm. There are several papers written that trash Michael Kasha's bracing theory and debunk the idea that there is a bass or treble side (section) to the sound board or bridge -- those that have seen the bridge will remember its radical shape. All the effort that went into the concepts were about "tuning" the tonal out-put of the instrument. Unfortunately, any validation was lost when Richard Schnieder hooked up with Gibson - the details of the ground work science were lost in an attempt at mass production.

[deadedith]

Here's a text clip from Dana's explanation - notice he does say 'beef up' the treble side. Interesting?

"Long ago, when I started building OMs, I became enchanted with their balance, clarity, and singing treble voice. For years I tried to get the same kind of voice out of larger guitars. Dreadnoughts naturally have a well-defined bass response, but rarely have equal presence in the treble register.

I realized that I had to beef up the treble side of the X in order to bring out the treble. Players like Bryan Sutton use every note on the fretboard. This is one of the most important ways to make sure he gets every note. We now use a variation of this design on every model we make, with the exception of the OM. "