Wren Build Thread ... last of 2018 ... Sitka/Koa

[Carey]

Beautiful, David. The contrast between the B/S wood and the binding is
particularly nice.

[BrunoBlack]

That’s a gorgeous guitar!

[TomB'sox]

I love the way the grain bends out into the lower bout. How did you do that haha?

[Ozzy the dog]

Originally Posted by David Wren

In this world of technology and precision machinery, it's great to see that perfection can still be achieved with a ball of string.

Just exactly how long is that piece of string?

[David Wren]

Originally Posted by Carey

Beautiful, David. The contrast between the B/S wood and the binding is
particularly nice.

Thanks Carey ... the customer wanted only spruce, koa and ebony on the body ... including the rosette ... we'll see how that works!

Originally Posted by Haasome

That’s a gorgeous guitar!

Thanks Paul!!!

Originally Posted by TomB'sox

I love the way the grain bends out into the lower bout. How did you do that haha?

The whole thing's just smoke and mirrors Tom!

Originally Posted by Ozzy the dog

In this world of technology and precision machinery, it's great to see that perfection can still be achieved with a ball of string.

Just exactly how long is that piece of string?

Hey Fred ... just long enough sometimes ... HA!

[David Wren]

[Tim McKnight]

Originally Posted by David Wren

Super clean work David. Are you tucking your braces and bridge plate? I can see a small bevel angle on the side finger braces and lower tone bars which lead me to believe that you do.

[j. Kinnaird]

Originally Posted by David Wren

Very pretty guitar David.
I would like to know what you do, if anything, at this stage of construction to make changes to the chaladni patterns.

[David Wren]

Originally Posted by Tim McKnight

Super clean work David. Are you tucking your braces and bridge plate? I can see a small bevel angle on the side finger braces and lower tone bars which lead me to believe that you do.

Hey Tim ... yes ... I notch the finger struts and the lower transverse tone bars into the X. I don't do the bridge plate though (if the plate ever needs to be replaced in future years, it'd be a nightmare if it was notched in).

[David Wren]

Originally Posted by j. Kinnaird

Very pretty guitar David.
I would like to know what you do, if anything, at this stage of construction to make changes to the chaladni patterns.

Hey John ... thanks for popping back in!

I very rarely make an instrument with sides (and back) with this low a mass (I'm usually using a heavy Dalbergia or similar), so I was curious to see how close to the edge the node line sat.

Once the box is closed, I don't do anything to it until the very end (once it's strung for a week or so). At that point, if there is too much admitance on a particular note, I'll use one of the techniques available to us to shift that resonant frequency. In the case of this instrument, if I think it lacks power, I might add mass (magnets usually) to the sides to move that node line and make the top (in theory) more efficient ... but I'll use my ears to make those decisions after string up.

[David Wren]

[David Wren]

[SJ VanSandt]

Originally Posted by David Wren

Hey John ... thanks for popping back in!

I very rarely make an instrument with sides (and back) with this low a mass (I'm usually using a heavy Dalbergia or similar), so I was curious to see how close to the edge the node line sat.

Once the box is closed, I don't do anything to it until the very end (once it's strung for a week or so). At that point, if there is too much admitance on a particular note, I'll use one of the techniques available to us to shift that resonant frequency. In the case of this instrument, if I think it lacks power, I might add mass (magnets usually) to the sides to move that node line and make the top (in theory) more efficient ... but I'll use my ears to make those decisions after string up.

Wow! Magnets! As a permanent part of the guitar? I've never heard of that - never even imagined it, actually. Do many luthiers do this?

[David Wren]

Originally Posted by SJ VanSandt

Wow! Magnets! As a permanent part of the guitar? I've never heard of that - never even imagined it, actually. Do many luthiers do this?

Hey Stan ... Trevor Gore has forgotten more than I'll ever know about this technique. I think of adding mass to the sides as a way to nudge the main resonant frequency of the top (and since everything is coupled, all the other main frequencies) without affecting structural integrity (shaving braces) or altering the response (adding mass to the top) ... and it can have the byproduct of moving that monopole node closer to the outside of the guitar (making the pumping action of that mode more efficient). I use magnets as a temporary way to see what effect more mass will do to the sound of the instrument and where it takes the main resonant frequencies (and by extension, if excessive admittance manifests on any notes associated with the main resonant frequencies). If more mass on the sides is ultimately decided on, usually you would glue in a two or four wood side struts with small bolts on them to accept steel washers of some description.

[David Wren]