I found this photograph a few days ago and found it very interesting. It is the interior of a cello. I'd forgotten that there is a stick jammed between the front and back, which seems to have a lot to do with sound production. I know violins, although much smaller, have very similar construction. You luthiers will enjoy this, but I think anyone interested in fine woodworking will find it interesting.
Here's a discussion of the complexity and anatomy of the wood parts you see here:
What Is the Purpose of a Soundpost in a Violin?
The soundpost holds up the top plate of the violin and supports the treble foot of the bridge (the side of the bridge that holds the A and E strings). The soundpost helps give the violin a fuller sound by transferring the vibrations from the higher two strings from the front of the instrument to the backplate.
Thanks to the soundpost, the whole instrument vibrates and makes a sound, rather than just the top.
The left side of the bridge is supported by the bass bar
– a strip of wood glued on the underside of the top plate directly below the bass foot of the bridge (the side of the bridge that holds the G and D strings). The bass bar runs parallel to the lower two strings and helps transfer vibrations through the instrument, similar to the soundpost.
Without the soundpost and bass bar, the top of the violin could very likely cave in
from the pressure of the bridge and strings! These two smaller inner parts of the instrument are vital.
The soundpost stays in place from the pressure of the top and bottom plates of the violin. There’s no glue involved! For this reason, we should never remove all four strings at once – this takes off a lot of the tension that keeps the soundpost in place, and it can fall.
Never attempt to move or replace your own soundpost – this should always be done by skilled luthiers! If the length of the soundpost is too tall, it can separate the top and bottom plates of the instrument, causing lots of problems down the line. If the soundpost is too short in length, it won’t stay in place.
I also found this diagram of a violin showing the placement of the parts.
Here's the website. Violin Soundpost: The Soul of the Instrument - Violinspiration
The average thickness of the wood on the front and back of a violin is between 2 and 2.7mm. That is very thin, which is so it can vibrate. There are 120 separate wood parts in a violin. There is speculation about why Stratavaru has such a rich sound. Turns out there are a number of factors that go together. The Maple they used grew during a very cold period in Europe, which means the growth rings and wood density was extremely high. Stratavari also had a secret recipe for soaking the wood he used, as well as his formula for finishing the instrument.
Many modern instruments have sound quality that competes with the Stratavari instruments, but they are still mostly hand made. Same applies to cellos and violas.