Official Luthiers Forum!

I just love it when someone like Alan can give an explanation the way he does, it makes much more sense to me afterwards. I may not agree (not saying that I disagree here), but that would be because of my lack of experimentation and the use of my own musing that may be hard to change. I still value the input and appreciate the insight of experience and experimentation.

Thank you Alan for your enlightenment.

_________________
My Facebook Guitar Page

"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson

[QUOTE=Alan Carruth]
What does this mean in terms of tone? Well, remember, the 'cross dipole' is much less effective at producing sound than the 'main top' mode. If the dipole comes in close to the main mode in frequency it will tend to 'steal' energy from the 'main top' vibration, with the result that the spectrum of the guitar will 'fall off' quickly above the tall 'main top' peak. This tends to give a 'sharp', 'bright' or 'cutting' sound, so tapering the braces tends to go in that direction. Scalloping them increases the pitch seperation between the 'main top' and 'cross dipole' mode frequencies, and thus increases both the height and width of the 'main top' peak in the output. The tone tends to be 'warm', 'full' or 'bassy', but perhaps lacking in 'clarity'. The extra amplitude gives you a lot of 'punch'.
[/QUOTE]

Cool!! Dang, just what I am trying to understand. Thanks Al.

Jeff

Joe, i do agree with you but my road is somewhat different than many, i really struggled to build my first one, no plan, no teacher, not much English for me so there was a lot of translation and i even went against some well intended advice from Mario which was to build with real wood instead of plywood, anybody in it's right mind would have listened to him but i did not because i knew what kind of person i was and was aware of the costs involved ahead vs the poor woodworking skills i had. My aim was really humble, it was to obtain a loud soundbox which i did. it didn't matter what my first would look like, i knew it was just a test. For the second and 3rd, i'm now using a plan but it's just a matter of filling certain gaps in my knowledge with guitar components dimensions and obtain easy to create templates. Like you say, i'm the kind of guy who will go ahead and forge my own opinions on what to do but in the case of my second and 3rd, i do not want to take any chances, i just wanna do it right for they are gifts to loved ones. FWIW, i do intend to listen to my wood and even create my own bracing style one day, others have done it so why wouldn't i eh? i've always been curious , it's a natural gift i have but in my case, i sometimes have to stop and listen but stiil think that after15-20 guitars, i'll have a pretty good idea of what i'm doing. The moral of your story is great and i have this in common with you, i charge ahead no matter what, maybe the plan is just the break i needed after 9 months of searching the answers like crazy!

Thanks bud

Thanks Mr Carruth, it's always a pleasure to read and understand your posts!

Thanks for answering my questions guys. I appreciate the input. So much
to learn...

Ross

Changing the back bracing doesn't have as much of an effect on the tone as changing the top bracing. After all, the top is what produces most of the sound. In fact, it's plausible to think that the back mostly 'wastes' energy.

What I've found is that 'tuning' the main back resonant mode can help in the bass range, but that's about as far as I've been able to get with it. I use X bracing on my backs because I like to tune them before assembling the box, and that makes it easier. However, I change my back brace schemes around ones in a while. Each new one sounds a little bit 'different', but 'better' is one of those long words.....