This isn't something I'm doing

[Danl8]

As a Guitar Building Procedure, this isn't something I'm doing, but this caught my eye at the factory and I'm curious about what others think about cutting into the top like this. Is it that this model doesn't have the usual geometry facilitating a proper neck angle or is something else being done? (pics below)

[JLT]

I've done this to preserve the neck angle while lowering the entire neck so that the unfretted fingerboard lines up (more or less) with the top of the bridge. I'm not sure if it's the best way to go, but it was my only way to get the geometry where I wanted it.

[MaineGeezer]

Seems as though you are just asking for the top to split next to the fingerboard. Splits happen there even with a full-thickness top, and that notch is going to be a huge stress concentrator.

But I'm mostly ignorant about guitar building, so maybe not.

[tippie53]

I am a Martin repair tech and I can tell you what this is
On the standard models D 18 and higher they are still using the dovetail joint. These are still hand fit.
In the 15 style and lower they are using what they are calling a simple dovetail joint. This is done by CNC and it will cut a slight pocket in the top and heel to accommodate the angle. In a way you can say the set the body to the neck on these. This took the place of the older tenon neck joint.