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Sit ups:)


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I will add this also.... Don't close your eyes to the fact that in the end - you are voicing "A Guitar" and not just "A Top."

There are a lot of knobs you can twiddle if you are that sort of person who can't leave well enough alone... We have talked about a few here.... But as I have made instruments - I have been amazed at how it is possible to "tune things in" somewhat... And then you start seeing some of the "tricks" that factory guitars use to get the tone (or lack thereof) which they do...

For example - the bridge is a critical component of the voicing of a guitar..... The weight and stiffness distribution has a giant impact on tone... Bridge bolts have a significant impact on tone because they add weight without stiffness... Notice how "early" bridge bolts were just small nuts and bolts to protect a flat bridge from peeling off a curved top... But then the manufacturers realized that these bridge bolts add weight to the bridge - which can "increase" the bass response of an otherwise stiff instrument... And now you see bridge bolts which are quite long and their attachment nuts are big heavy brass things rather than standard machine nuts.. Hmmm... They act a bit like a low pass filter.... These guys are fiddling with this weight to push a stiff, trebley guitar towards having some bass without ruining warranty...

That also explains why some Gibson guitars with those abominable gigantic adjustable bridges can sound pretty good.. The weight rounds out the bass in an otherwise super stiff structure. Remove that half pound of hardware and it makes the guitar louder - but way more trebley.. Then - you have to do a lot more other voicing work to push the balance of the instrument back towards where it was to start with... But when you do - you will probably lose some of the characteristic sound it had previously...

For example - the bridge is a critical component of the voicing of a guitar..... The weight and stiffness distribution has a giant impact on tone... Bridge bolts have a significant impact on tone because they add weight without stiffness... Notice how "early" bridge bolts were just small nuts and bolts to protect a flat bridge from peeling off a curved top... But then the manufacturers realized that these bridge bolts add weight to the bridge - which can "increase" the bass response of an otherwise stiff instrument... And now you see bridge bolts which are quite long and their attachment nuts are big heavy brass things rather than standard machine nuts.. Hmmm... They act a bit like a low pass filter.... These guys are fiddling with this weight to push a stiff, trebley guitar towards having some bass without ruining warranty...

That also explains why some Gibson guitars with those abominable gigantic adjustable bridges can sound pretty good.. The weight rounds out the bass in an otherwise super stiff structure. Remove that half pound of hardware and it makes the guitar louder - but way more trebley.. Then - you have to do a lot more other voicing work to push the balance of the instrument back towards where it was to start with... But when you do - you will probably lose some of the characteristic sound it had previously...[/quote]

I would consider it quite an assumption that the factories are doing anything like that intentionally to manipulate tone. It might be a side effect, but I would very much doubt that that is the reason for doing any of those thing. Factory changes are usually based on cost and expediency. So unless you have heard a designer in a factory specifically state that that is the reason for those designs or spchanges, I would think it an assumption.

I don't know Ed... I think they know more than you think... Especially since they have to differentiate their product lines as part of selling stuff to customers for a living...

And Asia is not the same place it was 20 years ago. These guys are looking to play in the bog leagues - not just accept whatever leavings everybody else has...

Quite a few of these Asian guitar assemblers are hiring consultants (like our own Trevor) to help them understand the impact of the designs on tone... These aren't guys who are coming in to teach them high volume assembly or Lean/Indistrial engineering/Six Sigma/Quality to improve their efficiency, quality, and workmanship... These are guys coming in to

Thanks

Well, who, with an interest in making decent guitars, would ever use bridge bolts in the first place?

The ones looking to play in the bog leagues.......

Well, I do that, too. Previous lives and all that.

Funny thing is, when you get old, you find you've done a lot of different things...

The Asian factories work to whatever price point the brand requests. They can be just as good as anywhere else, if you want to pay the money.

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

Thread started Oct 28, 2017; This topic never gets old for me.
Multiple books, Visual Analyzer 32, Robbie O'Brian voicing class at Mark Adams School of Woodworking and 3 dreadnaughts, this is #4:

How do you know when to stop the process on a top?

I've stopped several times. I've stopped for good now, fearing I'll go too far. Nothing text book technical but going for, and achieved, strong, clear musical variety of tones and my version of "spring back" when flexed, Dana B. style.

But how do you know it's time to stop, without going too far?

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Measure Twice,

Karl Borum

One easy indicator that you've gone too far with a top is Trevor's '2-degree rule': if the bridge rotates more than 2 degrees under string tension the top is probably not as strong as it should be. It's an easy measurement to make.

Mass loading using something like poster adhesive can be handy. You drop the pitch of, say, the main top mode by adding weight to the bridge, and see when it stops being an improvement. Then you remove the weight and start shaving braces, keeping an eye as you go on the bridge rotation. Since shaving the braces reduces mass as well as stiffness it usually gives a 'better' sound when you get to the target frequency, but, of course, you can't change just one mode.

+1 for the bridge rotation check.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.