Sound Hole Reinforcement question(s)

[Nigel Wickwire]

Roughly from the late eighties to the late nineties and maybe longer, Guild used a heavy plate sound hole reinforcement on some guitars. A pentagon-shaped piece that completely surrounds the sound hole.

Telenator touches on it briefly in the thread about his D15 rebuild:
http://letstalkguild.com/phpBB2/viewtopic.php?f=5&t=16537&start=0

Here is one of Telenator pic's (used without permission):

What is the general consensus of the value of this Reinforcement?

Is my time range correct? Or did they use them longer than that?

Edit: Was this used only on Dread's, or did this plate appear on other body styles?

Does it effectively turn a solid wood top into a plywood top, thereby diminishing the tone?

Or does in provide needed strength, reducing the chances of top cracks, particularly along the neck?

Anyone have any thoughts to share?

~nw

 

[devellis]

My guess is that it depends on everything else. The top is a unit that functions as a whole. Adding stiffness, in general, will boost trebles at the expense of bass. But if using this reinforcement plate allows the braces to be lighter, then that could offset those effects. Even without that plate, the area of the top in question isn't going to be the liveliest portion of the soundboard. The upper legs of the X brace, the heavy tapered brace where a "popsicle" brace often lives, the diagonal extensions beyond that brace, and the fingerboard extension are all going to dampen the upper bout to a petty substantial degree, leaving the lower bout as the primary contributor to sound. I don't know enough about how these things were built to offer much more of an answer than that. To echo my initial comment, though, putting in or taking out a single element of a top system will not typically replicate the voice of a top designed from the get-go with that element (either its presence or absence) as part of the original plan.

 

[taabru45]

Some times a little crack develops from the soundhole to the end of the edge of the fretboard, by the pickguard....perhaps this is a 'crack preventer???' Steffan

 

[Taylor Martin Guild]

I have a picking partner that plays an older maple Guild Dred. [1978?]
The top is sinking in at the sound hole up by the neck.
The sound hole brace pictured would possibly have prevented this from happening.
That may be why it's there now.

I gave him a humidifier to use and it has helped a little but the sinking top is still present and noticeable.

 

[Nigel Wickwire]

Steffan, TMG - I think you are probably right. Cracks by the sound hole could certainly be stopped or slowed down by that plate:

~nw

 

[plaidseason]

I have a fingerboard crack on my DV4 and it is basically pre-stablized by the existing bracing. My luthier examined it and said, "I don't think that's going anywhere."

-Chris

 

[capnjuan]

Steffan, TMG - I think you are probably right. Cracks by the sound hole could certainly be stopped or slowed down by that plate

Hi Nigel: probably so and one of these would stop those cracks too ... a 'spider' ... part of Guild's neck-block system:

 

[Nigel Wickwire]

My guess is that it depends on everything else. The top is a unit that functions as a whole. Adding stiffness, in general, will boost trebles at the expense of bass. But if using this reinforcement plate allows the braces to be lighter, then that could offset those effects. Even without that plate, the area of the top in question isn't going to be the liveliest portion of the soundboard. The upper legs of the X brace, the heavy tapered brace where a "popsicle" brace often lives, the diagonal extensions beyond that brace, and the fingerboard extension are all going to dampen the upper bout to a petty substantial degree, leaving the lower bout as the primary contributor to sound. I don't know enough about how these things were built to offer much more of an answer than that. To echo my initial comment, though, putting in or taking out a single element of a top system will not typically replicate the voice of a top designed from the get-go with that element (either its presence or absence) as part of the original plan.

Interesting insights, BD. I don't know if they lightened up the rest of the bracing or not, when they added the Sound hole plate.

Certainly with the "spider" reinforcement in CJ's pic, one would get the impression that the top bracing was designed with this in mind. The sound hole plate just kind of looks like an afterthought to me.

And what about Tone and Volume??

~nw

 

[devellis]

The effect could be big or small; only a comparison would tell. But I don't see how the guitar could get any bassier or louder as a result of adding the sound hole brace. So, if there's any appreciable change (which is an open question) I would expect it to be in the direction of brighter and softer. But guitars are strange beasts and what we expect isn't always what happens. For example, I've seen instruments that were louder with lighter gauge than heavier gauge strings, despite all that we might expect about a heavier string driving the sound board harder and thus producing more sound. These things are complex, integrated systems, so all sorts of unexpected things can happen.

 

[plaidseason]

You're absolutely right. Soundhole function is ridiculously complex. It's like that idea that a larger soundhole yields greater volume, when that's often not the case. Somewhere I read an article about the importance of the ratio of the soundhole vs. the overall size of the top, etc. It's crazy stuff. A soundhole with lighter bracing might create more volume, but it might also allow for less "focus."

Maybe.

-Chris