Responsive top and Responsive back

[Bob Moore]

Watching Ervin Somogyi today, in the videos elsewhere on this forum, I got interested in his talking about having the top and the back work together - from the experiment he showed with the rubber band and weight.
How do you go about doing that? How can you tweak both or either to make them complimentary?
Another question that came from reading about a build that Ray Kraut did. I got to listen to the buyer playing the guitar in the discussion. Here's the video of it: http://www.youtube.com/watch?v=PUsybHhC ... e=youtu.be

I was struck by the way each string sounded separate from the others. Like, as was said, each string was part of an orchestra.
What techniques can you use to try to get that separation? To make it simpler, how do you "voice" a guitar to equalize the treble with the bass?
I'm betting the answers would fill volumes and volumes.
Thanks,
Bob

[Herman]

Hey Bob,

I doubt if anyone here can give you the answers you're looking for. If there was a reciepe to do this, we would know by now. I guess there will be different approaches from our friend here.
My way to do it is to leave the top a bit on the thick side up till the box is closed. Then I tap all around and hear i fi like the sound. A "thud"is "too thick"and I start sanding the places where this appears. Along the way the top gets to sound like "poing". Then I stop.

The back I'll approach the same way, but I stay on the thick side. I have no way to "match" the top to the back.
I have a hard workboard where I let the body sit on its side. When I do work on, let's say, the neck, the body resonates to the sanding/hammering. If that occurs, I'm done. Then I believe in the future the body will move to external vibrations from strings. Not that sophisticated, is it?

About the video: It sounds to me that there is a lot of deceptive reverb used. Plus it sounds like there is an internal mike/piezo. My guess it's not only an external microphone. But nice sounds though.

Other visions, guys?
Herman

[Dave Bagwill]

I agree with Herman on the video. That is a really processed signal. No doubt the guitar sounds very good anyway, but if this was a comparison test, I think other quality instruments playing through the same rig would sound equally wonderful. It is a great sound!

Bob's question is beyond my knowledge to answer. Way beyond.

[ken cierp]

Way way way way --- processed! String and note seperation has a lot to do with "Bone tone" and that is the player's technique and tools -- stroke, nails, picks, strings matching the top flex and other subtlities. Playing a guitar without it touching one's torso has a huge affect on volume, tone, balance and seperation. Siminoff explains how the top needs to able to respond to the slighest vibration of each string -- shows how to build a fixture to test that out before the top is glued to the rim. BTW I do not think the rubber band demo thing is valid science. And many, including Irving, believe that simply having the back made out of a hard reflecitve material goes a long way in getting the two plates to work together --- how many millions of good guitars simply have that feature?

[Bob Moore]

Thanks all. Makes a lot of sense to me. But, it seemed like something to look at.
The guy in the video also was using a lower tuning. It was like CGCGDC or something way down.
And as was said it was processed.
As few guitars as I'll ever make, I won't be able to try this, try that. I'll just make my bracing as light as I can and see if it flies apart at some point.
Again, Thanks,
Bob

[Dave Bagwill]

An interesting and new internal mic from Baggs. Seems to overcome the drawbacks of previous internal mics.
http://youtu.be/Nzt3IHBTjLA
Also a clip from Phil Keaggy direct to board, no studio mic, just the lyric:




Bob - thanks for the posting - processed or not, that was a gorgeous sound.

[Ray Ussery]

An interesting and new internal mic from Baggs. Seems to overcome the drawbacks of previous internal mics.
http://youtu.be/Nzt3IHBTjLA
Also a clip from Phil Keaggy direct to board, no studio mic, just the lyric:




Bob - thanks for the posting - processed or not, that was a gorgeous sound.

VERY interesting...thanks for the post!